Search

Corticotropin-releasing hormone (CRH) is expressed in Barrington's nucleus (BarN), which plays an essential role in the regulation of micturition. To control the neural activities of BarN, glutamatergic and GABAergic inputs from multiple sources have been demonstrated; however, it is not clear how modulatory neurotransmitters affect the activity of BarN neurons. We have employed knock-in mice, CRH-expressing neurons of which are labeled with a modified yellow fluorescent protein (Venus). Using whole cell patch-clamp recordings, we examined the responses of Venus-expressing (putative CRH-expressing) neurons in BarN (BarCRH), as well as non-CRH-expressing neurons (BarCRH-negative), following bath application of cholinergic agonists. According to the present study, the activity of BarCRH neurons could be modulated by dual cholinergic mechanisms. First, they are inhibited by a muscarinic receptor-mediated mechanism, most likely through the M2 subclass of muscarinic receptors. Second, BarCRH neurons are excited by a nicotinic receptor-mediated mechanism. BarCRH-negative neurons also responded to cholinergic agents. Choline transporter-immunoreactive nerve terminals were observed in close proximity to the neurites, as well as the somata of BarCRH. The present results suggest that BarN neurons are capable of responding to cholinergic input.NEW & NOTEWORTHY This study investigates the effects of bath-applied cholinergic agonists on Barrington's nucleus (BarN) neurons in vitro. They were either excitatory, through nicotinic receptors, or inhibitory, through muscarinic receptors. Putative corticotropin-releasing hormone (CRH)-expressing neurons in BarN, as well as putative non-CRH-expressing neurons, responded to cholinergic agonists.

Barrington's nucleus (Bar), which controls micturition behavior through downstream projections to the spinal cord, contains two types of projection neurons, BarCRH and BarESR1, that have different functions and target different spinal circuitry. Both types of neurons project to the L6-S1 spinal intermediolateral (IML) nucleus, whereas BarESR1 neurons also project to the dorsal commissural nucleus (DCN). To obtain more information about the spinal circuits targeted by Bar, we used patch-clamp recording in spinal slices from adult mice in combination with optogenetic stimulation of Bar terminals. Recording of opto-evoked excitatory postsynaptic currents (oEPSCs) in 1,1'-dilinoleyl-3,3,3',3'-tetramethylindocarbocyanine, 4-chlorobenzenesulfonate (DiI)-labeled lumbosacral preganglionic neurons (LS-PGNs) revealed that both Bar neuronal populations make strong glutamatergic monosynaptic connections with LS-PGNs, whereas BarESR1 neurons also elicited smaller-amplitude glutamatergic polysynaptic oEPSCs or polysynaptic opto-evoked inhibitory postsynaptic currents (oIPSCs) in some LS-PGNs. Optical stimulation of BarCRH and BarESR1 terminals also elicited monosynaptic oEPSCs and polysynaptic oIPSCs in sacral DCN neurons, some of which must include interneurons projecting to either the IML or ventral horn. Application of capsaicin increased opto-evoked firing during repetitive stimulation of Bar terminals through the modulation of spontaneous postsynaptic currents in LS-PGNs. In conclusion, our experiments have provided insights into the synaptic mechanisms underlying the integration of inputs from Bar to autonomic circuitry in the lumbosacral spinal cord that may control micturition.NEW & NOTEWORTHY Photostimulation of BarCRH or BarESR1 axons in the adult mouse spinal cord elicits excitatory or inhibitory postsynaptic responses in multiple cell types related to the autonomic nervous system including preganglionic neurons (PGNs) in the lumbosacral intermediolateral nucleus and interneurons in the lumbosacral dorsal commissure nucleus. Integration of excitatory inputs from Bar and from visceral primary afferents in PGNs may be important in the regulation of micturition behavior.

We investigated the effects of ibandronate, a bisphosphonate; eldecalcitol, an active vitamin D3 analogue; and combination treatment with both agents on secondary osteoporosis and arthritis using rats with adjuvant-induced arthritis. Arthritis was induced in 8-week-old male Lewis rats. Rats were randomized into four treatment groups and an untreated normal control group: ibandronate, eldecalcitol, ibandronate + eldecalcitol, vehicle, and control. Paw thickness was measured to evaluate arthritis. Joint destruction was evaluated histomorphometrically by the ankle joint stained with Fast Green and safranin O. The femur and lumbar spine were scanned using dual-energy X-ray absorptiometry, and the distal femur was scanned using micro-computed tomography for bone mineral density (BMD) and trabecular microstructural evaluations. Ibandronate and/or eldecalcitol increased BMD in both the lumbar vertebrae and femur and improved several microstructural parameters (bone volume/total volume, structure model index, trabecular number, and trabecular separation of the distal femur). In addition, there was an additive effect of combination treatment compared with single treatments for most trabecular parameters, including BMD and bone volume. However, ibandronate and/or eldecalcitol did not inhibit arthritis and joint destruction. Combination treatment with ibandronate and eldecalcitol may be effective for secondary osteoporosis associated with arthritis.

The release of ATP from the epithelium of the urinary bladder (urothelium) in response to mechanical/chemical stimuli contributes to the visceral sensation in the micturition reflex. The nitric oxide (NO)‐mediated induction of cyclic guanosine monophosphate (cGMP) has been detected in urothelial cells and may inhibit the micturition reflex. However, the function of the NO‐cGMP pathway in the regulation of urothelial ATP release remains poorly understood in contrast to its effects on smooth muscles or primary afferent nerves. Therefore, we investigated the relevance of the NO‐cGMP pathway to ATP release on the mucosal side in the present study. The administration of l‐arginine (NO precursor) or NOC 12 (NO donor) significantly reduced ATP release to the mucosal side at a physiologically normal urine storage pressure (5 cmH2O). L‐NAME (NO synthase inhibitor) significantly increased the distention‐induced release of ATP. The phosphodiesterase‐5 inhibitor, sildenafil, which increases cGMP levels, inhibited distention‐induced ATP release. Furthermore, sildenafil significantly reduced ATP release in response to the administration of lipopolysaccharide. These results suggest that the NO‐cGMP pathway inhibited urothelial ATP release during the storage phase under both physiological and pathological conditions., The release of ATP from the epithelium of the urinary bladder (urothelium) contributes to the visceral sensation in the micturition reflex. We showed that nitric oxide‐cyclic guanosine monophosphate (NO‐cGMP) pathway inhibited the bladder ATP release in response to distention or lipopolysaccharide. Our study suggested that the NO‐cGMP pathway suppressed the micturition reflex during the storage phase by reducing urothelial ATP release under physiological and pathological conditions.

Objective To demonstrate the antinociceptive and antihypersensitivity mechanisms of Cris-104 (1-{2-[5-(4-fluorophenyl)-1H-pyrazol-4-yl]ethyl}piperidine), a novel selective α4β2* nicotinic acetylcholine receptor (nAChR) agonist, in rodent acute/inflammatory and chronic pain models. Materials and methods Hot-plate and formalin tests in mice were used to examine Cris-104-induced antinociceptive effects on thermal/inflammatory pain. Cris-104 effects on hypersensitivity, norepinephrine (NE) release in the spinal dorsal horn, and neuronal activity in the locus coeruleus (LC) were examined in rats with lumbar spinal nerve ligation using behavioral, microdialysis, and extracellular recording methods. Cris-104 effects on spontaneous locomotion were examined in an open-field test. Results Cris-104 induced dose-dependent antinociception effects in hot-plate and formalin tests, and these effects were blocked by the general nAChR antagonist mecamylamine, the selective α4β2* nAChR antagonist dihydro-beta-erythroidine, and the α2-adrenoceptor antagonist yohimbine, but not by the α1-adrenoceptor antagonist prazosin. Systemic and spinally perfused Cris-104 increased NE concentrations in microdialysates from the spinal cord in both normal and SNL rats. Systemic Cris-104 increased neuronal activity in the LC of normal rats. Mecamylamine blocked the effects of Cris-104 on spinal NE release and LC neuronal activity. Systemic Cris-104 did not affect locomotor activity significantly. Conclusion The α4β2 neuronal nAChR agonist, Cris-104, was effective for treatment of pain via descending noradrenergic inhibition of pain signaling.

Glucagon-like peptide-1 (GLP-1) is a peptide hormone and member of the incretin family. GLP-1 related drugs, such as liraglutide, are widely used to treat diabetic patients and work by stimulating pancreatic β cells to increase glucose-dependent insulin secretion. However, extrapancreatic effects, such as appetite suppression or emesis, are observed in response to GLP-1 receptor agonists. In this study we used the in vitro patch-clamp method in acute brainstem preparations of mice and demonstrated that GLP-1 acts directly on area postrema neurons. It is known that activation of the area postrema is related to the induction of homeostatic autonomic nervous systems, including nausea. Approximately,half of the neurons tested in the area postrema were excited by GLP-1 in the presence of tetrodotoxin, and is thought to be through adenylate cyclase-cAMP pathways. Excitation was not frequently observed in nucleus tractus solitaries neurons or in area postrema neurons from GLP-1 receptor knock-out mice. These results indicate that GLP-1 receptor agonists excite area postrema neurons and potentially leading to the expression of extra-pancreatic effects. This is the first study to show that GLP-1 directly activates area postrema neurons.

Operant methods that allow animals to avoid painful stimuli are interpreted to assess the aversive quality of pain; however, such measurements require investigator-initiated stimuli to animals. Here we developed a shuttle maze test to repeatedly assess activity associated nociception without forced stimulation. Rats ambulate back and forth between two treat feeders by taking either a short route with a prickly surfaced arch or a longer route with a smooth floor. L5–L6 spinal nerve ligation (SNL) reduced the preference for the short route with the arch, correlated with hypersensitivity in the hind paw. Oral gabapentin restored the short route preference and reduced hypersensitivity in SNL rats, and blockade of spinal α2-adrenoceptors reduced gabapentin’s effects on hypersensitivity but not on preference index. These results suggest that SNL injury alters behavior in the shuttle maze test and that the shuttle maze test shows comparable results to reflexive hypersensitivity after SNL in magnitude and response to gabapentin.

Noradrenergic modulation has been frequently discussed in the context of neural activities that are related to pelvic organs. The sacral preganglionic nucleus (SPN) is a spinal nucleus containing parasympathetic preganglionic neurons that send fibers to pelvic nerves. In spite of the abundant presence of noradrenergic fibers around the SPN, the effects of noradrenaline (NA) remain obscure. To explore this issue, NA (50 μM) was applied to parasympathetic preganglionic neurons in the SPN during whole-cell patch clamp recording. The SPN was labeled with the retrograde tracer, DiI. These neurons demonstrated two classes of firing patterns (delayed and regular) in terms of initiation of firing. Independent of these firing patterns, NA induced inward (56%) or outward (32%) currents in labeled SPN neurons. Phenylephrine, an α1 receptor agonist, induced an inward current, and clonidine, an α2 receptor agonist, induced an outward current, indicating the existence of both α1 and α2 adrenoreceptors in DiI-labeled SPN neurons. NA also modulated synaptic currents according to the firing patterns. In delayed firing neurons, NA inhibited both spontaneous excitatory post-synaptic currents (sEPSCs) and spontaneous inhibitory post-synaptic currents (sIPSCs). Hence, NA facilitated sEPSCs and sIPSCs in about a half of regular firing neurons. Bath application of phenylephrine facilitated sEPSCs and sIPSCs, and clonidine inhibited them. These results support the hypothesis of multiple effects of NA in the SPN, and may suggest functional differences among SPN neurons.

Serotonin [5-hydroxytryptamine (5-HT)] is involved in both motor and sensory functions in hollow organs, especially in the gastrointestinal tract. However, the involvement of 5-HT in visceral sensation of the urinary bladder remains unknown. Because distention-induced ATP release from the urothelium plays an essential role in visceral sensation of the urinary bladder, we investigated the regulation of urothelial ATP release by the 5-HT signaling system. RT-PCR and immunohistochemical analyses of the urothelium revealed specific expression of 5-HT1D and 5-HT4 receptors. The addition of 5-HT did not affect urothelial ATP release without bladder distention, but it significantly reduced distention-induced ATP release by physiological pressure during urine storage (5 cmH2O). The inhibitory effect of 5-HT on distention-elicited ATP release was blocked by preincubation with the 5-HT1B/1D antagonist GR-127935 but not by the 5-HT4 antagonist SB-204070. mRNA encoding tryptophan hydroxylase 1 was detected in the urinary bladder by nested RT-PCR amplification, and l-tryptophan or the selective serotonin reuptake inhibitor citalopram also inhibited ATP release, indicating that 5-HT is endogenously synthesized and released in the urinary bladder. The addition of GR-127935 significantly enhanced the distention-elicited ATP release 40 min after distention, whereas SB-204070 reduced the amount of ATP release 20 min after distention. These data suggest that 5-HT4 facilitates the distention-induced ATP release at an earlier stage, whereas 5-HT1D inhibits ATP release at a later stage. The net inhibitory effect of 5-HT indicates that the action of 5-HT on the urothelium is mediated predominantly by 5-HT1D.

Overactive bladder is one of the major health problem especially in elderly people. Adenosine triphosphate (ATP) is released from urinary bladder cells and acts as a smooth muscle contraction and sensory signal in micturition but little is known about the role of ATP release in the pathophysiology of overactive bladder. To assess the relationship between ATP and overactive bladder, we used a partial bladder outlet obstruction (pBOO) model in rats. The bladder caused several changes by pBOO: An increase in bladder weight, hypertrophy of sub-urothelium and sub-serosal area, and frequent non-voiding bladder contraction during urine storage. Basal ATP release from urothelium and serosa of pBOO rats was significantly higher than that of normal rats. Distentioninduced ATP release from urothelium of normal and pBOO rats had no significant change. However, distention-induced ATP release from serosa of pBOO rats was higher than that of normal. These findings may identify ATP especially released from serosa as one of causes of non-voiding contractions and overactive bladder symptoms.

Noradrenergic modulation has been frequently discussed in the context of neural activities that are related to pelvic organs. The sacral preganglionic nucleus (SPN) is a spinal nucleus containing parasympathetic preganglionic neurons that send fibers to pelvic nerves. In spite of the abundant presence of noradrenergic fibers around the SPN, the effects of noradrenaline (NA) remain obscure. To explore this issue, NA (50 μM) was applied to parasympathetic preganglionic neurons in the SPN during whole-cell patch clamp recording. The SPN was labeled with the retrograde tracer, DiI. These neurons demonstrated two classes of firing patterns (delayed and regular) in terms of initiation of firing. Independent of these firing patterns, NA induced inward (56%) or outward (32%) currents in labeled SPN neurons. Phenylephrine, an α1 receptor agonist, induced an inward current, and clonidine, an α2 receptor agonist, induced an outward current, indicating the existence of both α1 and α2 adrenoreceptors in DiI-labeled SPN neurons. NA also modulated synaptic currents according to the firing patterns. In delayed firing neurons, NA inhibited both spontaneous excitatory post-synaptic currents (sEPSCs) and spontaneous inhibitory post-synaptic currents (sIPSCs). Hence, NA facilitated sEPSCs and sIPSCs in about a half of regular firing neurons. Bath application of phenylephrine facilitated sEPSCs and sIPSCs, and clonidine inhibited them. These results support the hypothesis of multiple effects of NA in the SPN, and may suggest functional differences among SPN neurons.

Overactive bladder is one of the major health problem especially in elderly people. Adenosine triphosphate (ATP) is released from urinary bladder cells and acts as a smooth muscle contraction and sensory signal in micturition but little is known about the role of ATP release in the pathophysiology of overactive bladder. To assess the relationship between ATP and overactive bladder, we used a partial bladder outlet obstruction (pBOO) model in rats. The bladder caused several changes by pBOO: An increase in bladder weight, hypertrophy of sub-urothelium and sub-serosal area, and frequent non-voiding bladder contraction during urine storage. Basal ATP release from urothelium and serosa of pBOO rats was significantly higher than that of normal rats. Distentioninduced ATP release from urothelium of normal and pBOO rats had no significant change. However, distention-induced ATP release from serosa of pBOO rats was higher than that of normal. These findings may identify ATP especially released from serosa as one of causes of non-voiding contractions and overactive bladder symptoms.

Distention of the bladder during urine storage induces ATP release from urothelium, thereby facilitating transmission of visceral sensory signals to afferent nerve fibers. An excess of urothelial ATP release was found in interstitial cystitis, a condition accompanied by hyperesthesia of the urinary bladder; it remains unclear which signals are involved in this upregulation. The present study demonstrated that the adenylyl cyclase pathway enhances distention-induced ATP release in mouse bladder. In the absence of distention, adenylyl cyclase activation by forskolin or cyclic AMP increases by rolipram did not induce significant ATP release. However, forskolin or rolipram significantly enhanced ATP release from urothelium by a physiologically normal urine storage pressure (5 cmH(2)O). Blockade of adenylyl cyclases did not alter pressure-induced ATP release in normal condition. Thus, the adenylyl cyclase-cAMP pathway might be activated in pathological conditions and cause an excess of ATP release.

Takahashi H, Sugawara K, Satake M, Shioya T, Kagaya H, Kawatani M. Effects of low-intensity exercise training (Chronic Obstructive Pulmonary Disease Sitting Calisthenics) in patients with stable Chronic Obstructive Pulmonary Disease. Jpn J Compr Rehabil Sci 2011; 2: 5�12. Objective: The purpose of this study was to investigate the effectiveness of pulmonary rehabilitation (PR), consisting of chronic obstructive pulmonary disease (COPD) sitting calisthenics (CSC), which are performed in a seated position by outpatients with stable COPD. Methods: Sixty-seven males with stable COPD undergoing outpatient treatment were recruited. They were randomly assigned to either a calisthenics group (n = 35), which underwent PR consisting of CSC performed at home for 3 months and an educational program at the outpatient department, or a control group (n = 32) that underwent only a monthly outpatient educational program. Results: The peak oxygen uptake (VO 2 ) values for the aerobic CSC performed at target dyspnea ratings of 2 were 39.4�52.1% of the peak VO 2 values obtained

α1-Adrenergic receptor subtypes are widely distributed in the central nervous system and are involved in autonomic functions such as micturition. We investigated the presence and the role of supraspinal and/or spinal α1-adrenergic receptors in modulating the micturition reflex in conscious female Wistar rats. The expression of α1-adrenergic receptor subtypes in rat brain and lumbosacral spinal cord was studied using RT-PCR. Continuous-infusion cystometrograms were obtained in conscious rats, and α1-adrenergic receptor antagonists were administered via intracerebroventricular or intrathecal routes. The mRNA expression of α1A-, α1B-, and α1D-adrenergic receptors was detected in rat brain (midbrain and pons) and lumbosacral spinal cord (dorsal and ventral parts of spinal cord). In addition, intracerebroventricular injection of the α1-adrenergic receptor antagonist tamsulosin (1–10 μg), the selective α1A-adrenergic receptor antagonist silodosin (1–10 μg), and the selective α1D-adrenergic receptor antagonist BMY 7378 (1–10 μg) significantly prolonged the intercontraction interval (ICI) but did not alter maximum voiding pressure (MVP). Although intrathecal injection of BMY 7378 (0.0001–10 μg) did not affect ICI, tamsulosin and silodosin prolonged ICI in a dose-dependent manner. MVP was significantly reduced by intrathecal injection of tamsulosin (10 μg) but not by silodosin or BMY 7378 (0.0001–10 μg). Supraspinal α1A- and α1D-adrenergic receptors are apparently important for the regulation of reflex-bladder activity in conscious rats. Noradrenergic projection from the brain stem to the lumbosacral spinal cord may promote the afferent limb rather than the efferent limb of the micturition reflex pathway via α1A-adrenergic receptors.

Previous studies using specific antagonists have shown that α1-adrenergic receptors (AR) in the urinary bladder epithelium (urothelium) serve as a regulator of micturition reflex. To confirm the urothelial adrenergic effect on the micturition reflex, we investigated the functional role of the α1D-AR subtype in the urothelium on micturition reflex using α1D-AR knockout (α1D-KO) mice. An immunohistochemical analysis showed that the α1D-AR was localized to the umbrella cells in the mouse urothelium. Cystometry using wild-type mice demonstrated that the intravesical infusion of noradrenaline (NA) into the urinary bladder shortened the intercontraction interval (ICI) in a dose-dependent manner, without changing the maximum voiding pressure (MVP). In contrast, α1D-KO mice exhibited no change in the ICI in response to the intravesical infusion of NA. These results indicate a predominant involvement of the α1D-AR in facilitation of micturition reflex by NA. Interestingly, the intravenous injection of NA did not alter the ICI and the MVP in wild-type mice. Thus, locally releasing NA might play an important role in the facilitation of micturition reflex via the urothelial α1D−AR subtype.

It has been suggested that dopamine (DA) and serotonin (5-HT) and their receptors, particularly D(2)-like and 5-HT(2C) receptors, may play a significant role in the control of male sexual function. The purpose of this study was to investigate whether the combination of a dopamine receptor agonist apomorphine and a 5-HT(2) receptor agonist m-CPP would potentiate penile erection and ejaculation in male rats. Systemic administration of either apomorphine (0.01-0.1 mg/kg, s.c.) or m-CPP (0.01-0.3 mg/kg, i.p.) dose-dependently elicited penile erections, but did not induce ejaculation. When combined, there was a drastic increase in both the incidence of ejaculation and the amount of ejaculated seminal materials, while the proerectile effect induced by each drug was not potentiated. The proejaculatory effect induced by the combination of apomorphine (0.1 mg/kg, s.c.) and m-CPP (0.3 mg/kg, i.p.) was completely blocked by pretreatment with the D(2)-like receptor antagonists haloperidol and sulpiride, but not by the D(1)-like receptor antagonist SCH-23390. The synergistic action for ejaculation was also blocked by domperidone, the D(2)-like receptor antagonist that dose not cross the blood-brain barrier. The rats pretreated with the 5-HT(2C) receptor antagonist SB242084 did not show the synergistic action by the combination of apomorphine and m-CPP, whereas the rats pretreated with the 5-HT(2A) receptor antagonist ketanserin and the 5-HT(2B) receptor antagonist SB204741 showed the combination-induced synergistic action. These results suggest that the combination of a small dose of apomorphine and m-CPP potently and selectively facilitates the ejaculatory response through the activation of D(2)-like and 5-HT(2C) receptors, respectively. The D(2)-like receptors involved in the synergistic action may be, at least in part, located in the peripheral sites.

We examined the effects of loxoprofen, a cyclooxygenase inhibitor, and ONO-8711, an EP1-receptor antagonist, on afferent nerve activity during acetic acid (AA, 0.1% v/v)-induced inflammation of the rat urinary bladder. Distension stimulation was performed (vesical pressure of 30 cm H2O) for 2 min. The neuronal discharge was recorded from L6 dorsal root filaments. The discharge was observed just after the beginning of distension and increased gradually thereafter. When the vesical pressure returned to control value, the discharge diminished abruptly. AA infusion increased the total number of spikes to 198 +/- 38.8% of control values. AA infusion also produced asynchronous discharge in 39% of the animals. Loxoprofen administration (1 mg/kg, i.v.) reduced the number of spikes to 40.3 +/- 14.8% of control values. ONO-8711 administration (1 and 3 mg/kg, i.v.) reduced the number of spikes to 81.6 +/- 1.6% and 32.2 +/- 7.4% of control values, respectively. These data indicate that loxoprofen or EP1-receptor antagonist inhibit the inflammation-related neuronal activity. EP1 receptors in the peripheral afferent nerve terminal and/or urothelium may facilitate the primary afferent nerve activity, which elicits the inflammation-induced micturition reflex.

Aim: There is increasing evidence that non-steroidal anti-inflammatory drugs are effective for the treatment of nocturia. In this study, we attempted to investigate the role of loxoprofen sodium (loxoprofen) in the therapeutic management of patients with nocturia. Methods: Fifteen benign protastatic hyperplasia and/or overactive bladder patients (13 males and 2 females, 71.1 ± 1.5 years old) with three or more voids per night were involved. These patients had received standard drug therapy. Although these patients had received standard drug therapy for more than half a year, they had still three or more episodes of nocturia. The patients took a single dose of 60 mg of loxoprofen at night prior to sleep. Before and 1 week after the initiation of this therapy, the effects of this treatment were assessed by frequency volume chart and a questionnaire. Results: In the questionnaire, seven patients answered as excellent, six patients demonstrated improvement of their symptoms, two patients did not show a significant change in their symptoms and no patients demonstrated a deterioration in the symptoms. In frequency volume chart, total void per day, total void per night, total urine volume per day, total night urine volume per day and single voided volume in the night before and after this treatment were 9.97 ± 0.81 and 8.99 ± 0.74 per day, 3.82 ± 0.25 and 1.82 ± 0.27 per night, 1349 ± 81 and 1258 ± 91 mL per day, 567 ± 46 and 325 ± 51 mL per night, and 143 ± 13 and 149 ± 10 mL, respectively. Conclusions: Loxoprofen can be effective and useful for patients with nocturia. Our data suggest that the main mechanism of this effect is to decrease urine production during a night's sleep.

This study assessed the potential application and the effectiveness of functional magnetic stimulation (FMS) for preventing skeletal muscle atrophy in adult rats. FMS using magnetic stimulator was performed to rat soleus muscle by placing a round magnetic coil on the back of 3rd-5th lumbar vertebral level at 20 Hz frequency for 60 min/day up to 10 days. A reverse transcriptase-polymerase chain reaction was applied to evaluate relative amounts of mRNAs specific to four myosin heavy chain (MHC) isoforms [MHCIbeta, MHCIIa, MHCIIb, and MHCIId(x)] in rat soleus muscle during contractile activity by magnetic stimulation. Ten-day unloading by hindlimb suspension induced a drastic decrease of MHCIbeta and MHCIIa mRNA expressions, while MHCIIb and MHCIId(x) mRNA was not decreased. The magnetic stimulation resuscitated the down-regulation of the mRNA levels of MHCIbeta and MHCIIa. These results suggest that magnetic stimulation on acute atrophied muscles is useful for preventing the muscle atrophy.

Prostaglandins (PGs) are well known as one of the chemical mediators of inflammation. Nonsteroidal anti-inflammatory drugs (NSAIDs), PG synthesis inhibitors, are used for anti-nociception and/or anti-inflammation. We examine the effect of loxoprofen, an NSAID, on micturiton in acetic acid-induced bladder inflammation of the rats. In cystometrogram study with saline infusion into the urinary bladder, loxoprofen did not alter the interval of bladder contraction (IC, 107% of the control). IC was shortened by acetic acid infusion (65% of the control) and loxoprofen prolonged the IC (162% of acetic acid infused period). This prolonged IC was approximately same as the control. Loxoprofen did not alter the threshold pressure and the maximal voiding pressure. These data suggest that PGE2 might not play a part of normal micturition and may play a part of the micturition reflex during acetic acid infusion. That is, loxoprofen might be useful for pathological hyperreflex of the micturition.

Pituitary adenylate cyclase-activating polypeptide (PACAP) has been reported as a strong neurotrophic factor in the various sites of nervous system. The facial nerve injury is one of the common problems in patients at the Otolaryngology since the nerve damage could occur easily due to the anatomical characteristics. Once it happens, the regeneration is little observed and functional recovery is poor. Thus, we investigated that PACAP might have some influence for regeneration after the facial nerve transaction in the guinea pig. PACAP treatment accelerated time for the appearance of compound muscle action potentials (CMAP) after the nerve transaction (first appeared at 1 versus 2 weeks in control) and shortened the latency at 4 weeks. The number of myelinated fibers increased at 4 weeks. Histochemical demonstration of GAP-43, a growth cone protein, was observed at the injury area at 2-4 days. PACAP increased the level of glial cell line-derived neurotrophic factor (GDNF), a neurotrophin, in facial target muscles at 1 day-4 weeks. These data indicated that PACAP promotes the regeneration factors and increases the possibility of functional recovery following the facial nerve injury.

Prostaglandin E (PGE) induces the penile erection in the mammalians. Receptors for PGE were characterized to 4 different subtypes (EP1—4). The effects of agonists for EP1—4 receptors were studied on phenylephrine (PE, 1 μM)-induced contractions in the rabbit penile corpus cavernosum smooth muscle. The EP4 receptor agonist, ONO-AE1-329 (1 pM—10 μM), markedly relaxed the pre-contracted smooth muscle strips in a concentration-dependent fashion (−65 ± 16% relaxation at 10 nM). The EP2 receptor agonists, ONO-AE1-259-01 (1 nM—10 μM) or butaprost (1 nM—10 μM), also relaxed the smooth muscle strips in a concentration dependent fashion (−58 ± 10% relaxation at 10 μM or −53 ± 10% relaxation at 10 μM). The EP1 receptor agonist, ONO-DI-004 (0.01—10 μM), increased the contractility in the smooth muscle strips. A 12 ± 6% increase was observed with 10 μM of the agonist. The EP3 receptor agonist, ONO-AE-248 (0.01—10 μM), however, did not alter the contractility of the smooth muscle strips. The selective EP4 receptor antagonist, ONO-AE3-208 (0.1 μM), inhibited a relaxant response to ONO-AE1-329 (the EP4 receptor agonist) but did not affect a relaxant response to ONO-AE1-259-01 (the EP2 receptor agonist). It is likely that the relaxant effect of ONO-AE1-329 acts on the EP4 receptor. Neither a nitric oxide synthase (NOS) inhibitor, L-NAME (300 μM), nor a soluble guanylyl cyclase inhibitor, ODQ (30 μM), affected the relaxant responses to ONO-AE1-259-01 (0.1—10 μM) or ONO-AE1-329 (0.01 nM—1 μM). In summary, EP4 and/or EP2 receptors mediate relaxations in rabbit corpus cavernosum smooth muscle, and the EP4 relaxant system is higher in relaxant potency than the EP2 system. Furthermore, the relaxations are independent from a nitric oxide (NO)/cGMP signalling pathway.

The purpose of this study was to examine the ventilatory responses during a six-minute walk test (6MWT), an incremental shuttle walking test (ISWT), and a cycle ergometer test (CET) in patients with chronic obstructive pulmonary disease. Twelve subjects (11 male, age 72.2 years, with a forced expiratory volume in one second of 53.6% of the predicted normal) took part in the study. Throughout the three exercise tests, oxygen uptake (V'O 2 ), carbon dioxide production (V'CO 2 ), minute ventilation (V'E), and heart rate (HR) were measured using a portable breath-by-breath system. Oxygen saturation (SpO 2 ) and breathlessness were recorded at the end of each minute during the tests. There were no significant differences among the three exercise tests in terms of the peak values for V'O 2 , V'CO 2 , V'E, HR, and breathlessness. SpO 2 was significantly lower in both walking tests (6MWT: 89.8 ′ 3.3%, ISWT: 88.9 ′ 3.8%) compared to values in the CET (93.3 ′ 2.3%) (p < 0.05). V'O 2 during the 6MWT increased sharply for 2 minutes, and then showed a steady-state profile. During the CET and the ISWT, however, V'O 2 increased with respect to workload. In conclusion, the three tests clearly measure different aspects of exercise tolerance and should be considered complementary.

Excitatory pathways from the dorsal commissure (DCM) to L6–S1 parasympathetic preganglionic neurons (PGN) were examined using whole-cell patch-clamp recording techniques in spinal cord slices from neonatal rats. PGN were identified by retrograde axonal transport of a fluorescent dye injected into the intraperitoneal space. Excitatory postsynaptic currents (EPSCs) were evoked in PGN by stimulation of DCM in the presence of bicuculline methiodide (10 μM) and strychnine (1 μM) to block inhibitory pathways. Electrical stimulation of DCM evoked two types of inward currents. In the majority of PGN ( n = 66), currents (mean amplitude, 47.9 ± 4.7 pA) occurred at a short and relatively constant latency (3.8 ± 0.1 ms) and presumably represent monosynaptic EPSCs (Type 1). However, in other neurons ( n = 20), a different type of EPSC (Type 2) was noted, consisting of a fast monosynaptic component followed by a prolonged inward current with superimposed fast transients presumably representing excitatory inputs mediated by polysynaptic pathways. Type 1 EPSCs were pharmacologically dissected into two components. A fast component was blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 5μM) and a slowly decaying component was blocked by 2-amino-5-phosphonovalerate (APV, 50 μM). The fast component of Type 1 EPSCs had a linear current-voltage relationship and reversed at a membrane potential of −7.6 ± 1.3 mV ( n = 5). The fast component of Type 2 EPSCs was also blocked by 5 μM CNQX and the remaining slower component was blocked by 50 μM APV. When the DCM was stimulated in the presence of 50 μM APV, the time to peak and decay time constant in Type 1 EPSCs were 1.9 ± 0.2 and 4.1 ± 0.8 ms, respectively. Examination of the NMDA receptor-mediated component of the EPSCs in the presence of 5 μM CNQX revealed a current-voltage relationship that had a region of negative slope conductance (from −20 to −80 mV), which was abolished in Mg2+-free external solution. The time to peak and decay time constant of this component were 14.2 ± 2.0 and 91.0 ± 12.4 ms, respectively. Type 1 EPSCs in some PGN responded in an all-or-none manner and presumably represented unitary synaptic responses; whereas Type 2 EPSCs always exhibited a graded stimulus intensity–response relationship. Paired-pulse facilitation (50-ms interstimulus intervals; 141 ± 5.6% increase, n = 8) of EPSCs was observed. These results indicate that PGN receive monosynaptic and polysynaptic glutamatergic excitatory inputs from neurons and/or axonal pathways in the DCM.

Prostaglandin E(2)(PGE(2)) elicits a variety of effects by activating four subtypes of receptors, EP1, EP2, EP3 and EP4. We examined receptor subtypes mediating the effects of PGE(2) on parasympathetic preganglionic neurons that regulate the activity of pelvic visceral organs. In tonic parasympathetic preganglionic neurons in neonatal rat spinal slices, PGE(2) increased the firing frequency to depolarizing current pulses, induced after-discharges and inhibited spike after-hyperpolarization. PGE(2) did not affect phasic preganglionic neurons. An EP1 agonist inhibited after-hyperpolarizations and induced after-discharges, whereas EP4 agonist reduced after-hyperpolarization and increased evoked firing but did not induce after-discharges. EP2 and EP3 agonists were inactive. These results indicate that PGE(2) acting via EP1 and/or EP4 receptors modulates the excitability and/or excitatory synaptic input to tonic parasympathetic preganglionic neurons.

An immunohistochemical examination of cultured corpus cavernosum cells of the rabbit showed that they were composed of many smooth muscle cells retaining α-smooth muscle actin and a few of endothelial cells. Application of noradrenaline (NA, 0.5–100 μM) to the culture dose-dependently increased cytosolic concentrations of Ca 2+ ([Ca 2+ ] i ) in smooth muscle cells. The NA (10 μM)-induced [Ca 2+ ] i increase was dose-dependently inhibited by phenoxybenzamine (1 nM–1 μM). The inhibition was 71% at 0.1 μM and was completely made at 1 μM. An α 1 -adrenoceptor antagonist, prazosin (0.1 μM), inhibited the [Ca 2+ ] i response by 42%, and propranolol (1 μM) enhanced the response by 118%. These adrenoceptor antagonists showed almost the same effects on a contractile response of corporal tissue strips to NA (10 μM) as the effects on the [Ca 2+ ] i response. Our results suggest that NA-induced [Ca 2+ ] i increase was mixed with a large increase through α 1 -adrenoceptors and a small decrease through β-adrenoceptors. The increased [Ca 2+ ] i could play a role of intracellular messenger for leading to contraction of cavernosal smooth muscle cells.

We examined the inhibitory effects of loxoprofen, a cyclooxygenase inhibitor, and glycine, a major inhibitory neurotransmitter, on the micturition reflex in conscious rats and hypothesized that these drugs would interact synergistically to inhibit micturition. Voiding behaviors were assessed using a metabolic cage. Oral loxoprofen decreased the urinary frequency, and only a high dose(10 mg/kg) significantly reduced the voided volume. With cystometry, intravenous loxoprofen(0.1-3 mg/kg) and glycine (30 and 100 mg/kg) prolonged the intercontraction intervals (ICI) in adose-dependent manner, but did not change the maximum voiding pressure (MVP) in conscious rats. The combination of loxoprofen (3 mg/kg) and glycine (100 mg/kg) strongly prolonged the ICI more than with either drug alone. The lowest dose of loxoprofen (0.1 mg/kg) and glycine(30 mg/kg) did not affect either the ICI or the MVP, but their combination resulted in a significant increase in the ICI. These results suggest that the combined administration of loxoprofen and glycine produced a synergistic inhibitory effect on the micturition reflex.

Excitatory postsynaptic currents (EPSCs) in parasympathetic preganglionic neurons (PGNs) were examined using the whole cell patch-clamp recording technique in L6and S1spinal cord slices from neonatal rats (6–16 days old). PGNs were identified by labeling with retrograde axonal transport of a fluorescent dye (Fast Blue) injected into the intraperitoneal space 3–7 days before the experiment. Synaptic responses were evoked in PGNs by field stimulation of the lateral funiculus (LF) in the presence of bicuculline methiodide (10 μM) and strychnine (1 μM). In approximately 40% of the cells (total, 100), single-shock electrical stimulation of the LF elicited short, relatively constant latency [3.0 ± 0.1 (SE) ms] fast EPSCs consistent with a monosynaptic pathway. The remainder of the cells did not respond to stimulation. At low intensities of stimulation, the EPSCs often occurred in an all-or-none manner, indicating that they were mediated by a single axonal input. Most cells ( n = 33) exhibited only fast EPSCs (type 1), but some cells ( n = 8) had fast EPSCs with longer, more variable latency polysynaptic EPSCs superimposed on a slow inward current (type 2). Type 1 fast synaptic EPSCs were pharmacologically dissected into two components: a transient component that was blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 5 μM), a non-NMDA glutamatergic antagonist, and a slow decaying component that was blocked by 2-amino-5-phosphonovalerate (APV, 50 μM), a NMDA antagonist. Type 2 polysynaptic currents were reduced by 5 μM CNQX and completely blocked by combined application of 5 μM CNQX and 50 μM APV. The fast monosynaptic component of type 1 EPSCs had a linear current-voltage relationship and reversed at a membrane potential of 5.0 ± 5.9 mV ( n = 5), whereas the slow component exhibited a negative slope conductance at holding potentials greater than −20 mV. The type 1, fast synaptic EPSCs had a time to peak of 1.4 ± 0.1 ms and exhibited a biexponential decay (time constants, 5.7 ± 0.6 and 38.8 ± 4.0 ms). In the majority of PGNs ( n = 11 of 15 cells), EPSCs evoked by electrical stimulation of LF exhibited paired-pulse inhibition (range; 25–33% depression) at interstimulus intervals ranging from 50 to 120 ms. These results indicate that PGNs receive monosynaptic and polysynaptic glutamatergic excitatory inputs from axons in the lateral funiculus.

The effects of PACAP-38 on phasic and tonic preganglionic neurons (PGN) in L6 and S1 spinal cord slices from neonatal rats (5--11 days old) were studied using the whole-cell patch clamp technique. PGN were identified by retrograde axonal transport of a fluorescent dye (Fast Blue, 5 microl of 4% solution) injected into the intraperitoneal space 3--7 days prior to the study. Bath application of pituitary adenylate cyclase activating polypeptide (PACAP) (20 nM) increased the frequency of spontaneous excitatory postsynaptic potentials (EPSPs) and spontaneous firing in both types of PGN. PACAP markedly increased the number (200--800%) and frequency of action potentials elicited by depolarizing current pulses in phasic PGN, but had a smaller effect on tonic PGN. PACAP decreased the threshold for action potential generation by approximately 25% in both types of neurons (e.g. -34.0+/-1.5 to -38.4+/-1.7 mV from a holding potential of -50 mV in phasic PGN, P

The effect of dibutyryl cGMP (dbcGMP), a membrane permeant cGMP analogue, on cytosolic concentrations of Ca2+ ([Ca2+]i) was studied in cultured nodose ganglion neurons of the rabbit using fura-2AM and microfluorometry. Application of dbcGMP (10-1000 microM) increased [Ca2+]i in 42% of neurons (n=67). The effect was observed in a dose-dependent fashion. The threshold dose was 100 microM and the increase at 500 microM averaged 117+/-8%. Removal of extracellular Ca2+ abolished the dbcGMP effect. Application of Ni2+ (1 mM) or neomycin (50 microM), a non-L-type voltage-gated Ca2+ channel (VGCC) antagonist, eliminated the dbcGMP effect. omega-conotoxin GVIA (2 microM), the N-type Ca2+ channel antagonist, or L-type Ca2+ channel antagonists (D600, 50 microM, or nifedipine, 10 microM) did not alter the dbcGMP effect. Ryanodine (10 microM) did not alter the effect of dbcGMP. Therefore, cGMP could play a part of role of an intracellular messenger in primary sensory neurons of the autonomic nervous system.

Spinal cord injury disrupts micturition reflexes, which produces morbidity. The contribution of endogenous opioid systems to urinary retention were assessed in chronic spinal cats by administering the opioid receptor antagonist, naloxone (5-500 micrograms kg-1, i.p.), to unanesthetized paraplegic cats while monitoring lower urinary tract function and observing hind limb reflexes. While naloxone had no overt effect in acute spinal cats, in chronic spinal cats naloxone induced the release of large volumes of urine and produced marked hind limb hyper-reflexia. Prominent tachyphylaxis and tolerance to the effects of naloxone were evident. Immunohistochemical studies indicated a marked increase in leucine enkephalin and dynorphin in sacral spinal neurons. Together, these data indicate hyperactivity of the endogenous spinal opioid system following recovery from spinal cord injury and, furthermore, suggest that the spinal neural circuitry may become 'dependent' upon elevated levels of endogenous opioid peptides.

Afferent neurons projecting to the clitoris of the cat were identified by WGA-HRP tracing in the S1 and S2 dorsal root ganglia. An average of 433 cells were identified on each side of the animal. 85% and 15% of the labeled cells were located in the S1 and S2 dorsal root ganglia, respectively. The average cross sectional area of clitoral afferent neuron profiles was 1,479 +/- 627 micron2. Unilateral transection of the pudendal nerve reduced the number of labeled cells to 1% of that on the control side. Central projections of clitoral afferents were identified in the lumbo-sacral segments (L7-S3) of the spinal cord. HRP labeled fibers were located in the marginal zone on the medial side of dorsal horn and extended into the dorsal half of the dorsal gray commissure. Electrophysiological recordings detected axonal volleys in the pudendal nerve and S1 dorsal root in response to electrical stimulation (threshold, 1-4 V) of the clitoral surface. Estimated axonal conduction velocities at the two sites ranged from 7-27 m/s and 0.6-30 m/s, respectively. Multi-unit recordings from dorsal roots in the lumbo-sacral segments revealed that non-noxious pressure stimulation of the clitoris evoked discharges in the S1 dorsal root. Small increases were also detected in the S2 and L7 roots. Single unit discharges recorded from S1 dorsal roots were activated by electrical stimulation of the clitoral surface at thresholds of 0.6-1.2 V and latencies of 1.5-1.8 ms (estimated conduction velocities of 24-30 m/s.(ABSTRACT TRUNCATED AT 250 WORDS)

A Ga-Al-As diode system that produces low-energy red light (830 nm, 40 mW) has been used for the treatment of many kinds of pain. The mechanism of action of this new laser irradiation for analgesia was studied in anesthetized rats. The effect of laser irradiation of the saphenous nerve was studied by recording neuronal activity at the L4 dorsal root filaments after the injection of a chemical irritant, turpentine. Laser irradiation inhibited both the asynchronous firing by that was induced by turpentine and increased part of the slow components of the action potentials. Thus, the laser irradiation selectively inhibited nociceptive signals at peripheral nerves.

Epithelial cells in the urinary bladder (urothelium) trigger sensory signals in micturition by releasing ATP in response to distention of the bladder wall. Our previous study revealed the distinct roles of extracellular Ca2+ and the Ca2+ stores in the endoplasmic reticulum (ER) in urothelial ATP release. In the present study, we investigated the regulation of urothelial ATP release by Ca2+ influx from the extracellular space and Ca2+ release from the ER using a distention assay of the mouse bladder wall in a small Ussing chamber. Stimulation of Ca2+ release from the ER in the mucosal side of the bladder induced significant ATP release without distention. Blockade of the inositol 1,4,5-triphosphate receptor reduced distention-induced ATP release, suggesting that Ca2+ release from the ER is essential for the induction of urothelial ATP release. On the other hand, blockade of store-operated Ca2+ entry (SOCE) from the extracellular space significantly enhanced distention-induced ATP release. Thus Ca2+ release from the ER causes urothelial ATP release and depletion of Ca2+ stores in the ER, which in turn causes the depletion-inducing SOCE to suppress the amount of urothelial ATP released.

Accumulating evidence shows that the epithelial cells in urinary bladder (urothelium) serve as a sensory organ in micturition and/or in nociception pathway by releasing ATP in response to mechanical and/or chemical stimuli. Here, we compared the effects of capsaicin, acetylcholine, and prostaglandin E(2) receptor EP1 agonist (ONO-DI-004) on the urothelial ATP release in primary cultured mouse urothelial cells in low Ca(2+) medium. All of these chemicals induced a gradual ATP release from urothelium, implying that the downstream Ca(2+) release from endoplasmic reticulum could trigger the ATP release. Consistent with this suggestion, blockade of inositol 1,4,5-triphosphate receptor reduced the distention-induced ATP release from urothelial tissues. The distention-induced ATP release was not affected by tetrodotoxin. However, an increase in extracellular Ca(2+) diminished both chemical- and distention-induced ATP release from urothelium. Thus raising the extracellular Ca(2+) concentration was found to inhibit stimulation-evoked ATP urothelial release.

The current study was undertaken in an attempt to characterize the functional properties of urothelial alpha1A adrenergic receptors, especially in modulating the micturition reflex. The expression of alpha1A receptors in rat bladder was analyzed by immunohistochemistry and Western blotting. As a functional study, we obtained continuous infusion cystometrograms in conscious rats using noradrenaline (NA) and subtype selective alpha1 adrenergic receptor antagonists, tamsulosin (alpha1A/alpha1D selective) and silodosin (alpha1A superselective). Alpha1A receptors were immunohistochemically detected in rat urothelium. Intravesical infusion of NA (60 microM) significantly shortened the intercontraction interval (ICI). Pretreatment with tamsulosin at a dose of 0.4 microg/kg i.v. abolished intravesical NA infusioninduced reduction of ICI. Neither intravesical infusion of tamsulosin (20 microM) nor that of silodosin (0.2 microM) significantly altered ICI. After intravesical infusion of silodosin, intravesical NA infusion did not affect ICI. Urothelial alpha1A receptors might modulate bladder afferent activity under pathophysiological conditions with augmented concentrations of NA in blood or urine.

We investigated the presence of EP1 receptor in the urothelium and its role in micturition reflex by examining the effect of intravesical administration of prostaglandin E(2) (PGE2), an EP1 agonist (ONO-DI-004), acetic acid, and capsaicin. Age-matched EP1-KO mice and C57BL/6 wild-type (WT) mice were used. Western blots and standard immunohistochemical procedures were performed. Cystometrygram (CMG) was performed without anesthesia in a restraining cage. ATP release from the cultured urothelium cells was performed using luciferin-luciferase luminometry. The EP1 receptor was found to be present in the urothelium. In WT mice, PGE2 infusion shortened the intercontraction interval (ICI) in a dose-dependent fashion; however, it did not alter the ICI in EP1-KO mice. The EP1 agonist significantly shortened the ICI in WT mice, but not in EP1-KO mice. Acetic acid and capsaicin shortened the ICI in both WT mice and EP1-KO mice. EP1 agonist, PGE2 and capsaicin provoked ATP release from cultured urothelial cells. These results suggest that EP1 receptor was present in bladder urothelium, and could be activated by PGE2 to release ATP. EP1 receptor in urothelium might be important for reflex voiding in pathological conditions.

Endogenous opioids tonically regulate micturition in adult mammals. The present study sought to determine if opioids regulate micturition in neonatal kittens. Naloxone (up to 2 mg/kg given i.p. or i.v. to unanesthetized/ketamine-anesthetized or chloralose-anesthetized kittens, respectively), an opioid receptor antagonist, produced no effects in unanesthetized, ketamine-anesthetized, or chloralose-anesthetized kittens that had been prepared for bladder pressure recording, until 3 weeks of age. This indicates that endogenous opioids are not tonically regulating micturition in neonatal kittens. From 3 weeks up to at least 6 weeks of age, naloxone (100 μ/kg i.p. or i.v.) weakly facilitated bladder activity by transiently μ/kg i.p. or i.v.) weakly facilitated bladder activity by transiently increasing the amplitude and/or duration of bladder contractions, but no effect on frequency of contractions was recorded. Morphine (up to 2 mg/kg given i.p. or i.v. to unanesthetized/ketamine-anesthetized or chloralose-anesthetized kittens, respectively), an opioid agonist, did not inhibit bladder contractions in unanesthetized or ketamine-anesthetized neonatal kittens, but it did inhibit (at a threshold dose of 100 μ/kg) and completely abolished (at a dose of 300 μ/kg) bladder activity in chloralose-anesthetized kittens in a dose-dependent, naloxone-reversible manner. Surprisingly, following morphine administration to unanesthetized or ketamine-anesthetized neonatal kittens, naloxone now produced an adult-like enhancement of bladder activity. These latter results indicate that opioid receptors, whose inhibitory effects are anesthetic-dependent, are present along the micturition reflex pathway in neonates. Immunohistochemical studies of the sacral spinal cord revealed that opioid peptides are distributed similarly in neonatal and adult cats.

Catchlike property is the force enhancement produced when a brief, high-frequency burst of pulses is added to a constant low-frequency stimulation. In functional electrical stimulation, constant low-frequency stimulation of approximately 20 Hz has primarily been used to reduce muscle fatigue. The purpose of this study was to investigate the effects of catchlike-inducing intermittent stimulation on muscle fatigue in relation to continuous intermittent low-frequency stimulation. Twenty-two adult male Wistar ST rats were randomly assigned into the constant frequency stimulation (CFS) group or the catchlike-inducing stimulation (CIS) group. In the CFS group, constant low-frequency stimulation of 20 Hz was applied intermittently (4 seconds "ON"/15 seconds "OFF"). In the CIS group, a single electrical burst of 100 Hz was applied at the start of the every 4-second period of stimulation. The muscle fatigue test lasted for 16 min and isometric muscle force, muscle fatigue, and muscular workload were evaluated. CIS significantly increased the maximum muscular force (under fatigued condition) and workload, and significantly decreased muscle fatigue (p0.05). The results of this study suggest that catchlike-inducing intermittent electrical stimulation is useful in the clinical administration of functional electrical stimulation.

We studied the movement of center of gravity (CG) in young and aged subjects during maximum grip of right or left hand. Body-sway was recorded with stabilometry in rest-stand position and in maximum grip. The data from right-or left-handed young subjects were analyzed. Maximum grip power was not different between dominant hand and un-dominant hands. Total length (LNG) and total movement area of CG (REC AREA) during the measurements were significantly larger in maximum grip than in rest-stand. In right-handed subjects, LNG increased to 245% and 250% of rest-stand value, and REC AREA increased to 589% and 633% in right and left hand grip, respectively. In left-handed subjects, LNG increased to 186% and 188% of rest-stand value, and REC AREA increased to 400% and 533% in right and left hand grip, respectively. No significant difference of LNG and REC AREA was observed between right and left hand grip in either hand dominant subject Maximum grip did not affect CG in rest-stand. In aged subjects, maximum grip power was significantly less than in young subjects (48%). LNG and REC AREA in rest-stand were significantly larger in aged subjects than in young subjects (220% and 400%, respectively). They were not different during maximum grip with either hand. While aged subjects have difficulty of controlling CG in rest-stand, they have less problems to stabilize CG during maximum grip. These data indicated that dynamic movement of CG might be important to understand person's activity of daily living.

In most subjects with spinal cord injury, the spinal neurons below the level of injury are spared. Therefore, it is conceivable that the skeletal muscles innervated by these spinal nerves can be activated by applying therapeutic magnetic stimulation along the dorsal spine. The purpose of this study was to evaluate the ability of magnetic stimulation to prevent acute muscle atrophy in rats after hindlimb suspension. Forty adult male Wistar rats were randomly assigned to stimulated and non-stimulated (control) groups. Their hindlimbs were unweighted using a suspension method, causing muscle atrophy. In the stimulation group, magnetic stimulation (20 Hz, 60 min per day) was applied to the sciatic nerve for 10 days. After the stimulation period, the tibialis anterior (TA) and extensor digitorum longus (EDL) were surgically removed and histologically measured. The lesser diameters of type 1, 2A, and 2B muscle fibers were significantly greater in the stimulated group than in the non-stimulated group for both the TA and EDL (p < 0.05). The mean difference in lesser fiber diameter was 20% (range, 14%-27%). These results suggest that therapeutic magnetic stimulation is an effective method of preventing muscle atrophy.

The electrophysiological properties of parasympathetic preganglionic neurons (PGN) in L6 and S1 spinal cord slices from neonatal rats were studied using the patch clamp techniques. PGN were identified by retrograde axonal transport of a fluorescent dye (Fast Blue) injected intraperitoneally before the experiment. PGN in the intermediolateral region of the spinal cord were divided into two classes (tonic PGN and phasic PGN) on the basis of firing properties during prolonged (300 ms) depolarizing current pulses. Tonic neurons exhibited a prolonged discharge (average maximum: 5.6); whereas phasic PGN fired on average only 1.4 spikes during depolarizing pulses. PGN were usually oval in shape. The mean long axis of tonic PGN (20.7+/-0.5 microm) was significantly (P