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Background: The rat has served usefully as a model for fecal incontinence and exploration of the mechanism of action of sacral neuromodulation. However, there is a gap in knowledge concerning representation(s) on the primary sensory cortex of this anatomical region., Methods: Multi-electrode array (32 channels) and intrinsic optical signal (IOS) processing were used to map cortical activation sites following anorectal electrical stimulation in the rat. A simple method for expanding a 32-electrode array to a virtual 2700 array was refined., Key Results: The IOS method identified activation of parietal cortex following anorectal or first sacral nerve root (S1) stimulation; however, the signal was poorly localized and large spontaneous vasomotion was observed in pial vessels. In contrast, the resulting high-density maps showed two anatomically distinct cortical activation sites to anorectal stimulation., Conclusions & Inferences: There are two distinct sites of activation on the parietal cortex following anorectal stimulation in the rat. The implications for sacral neuromodulation as a therapy for fecal incontinence are discussed., (© 2019 John Wiley & Sons Ltd.)

Objective: The aim of this study was to identify the facial areas defined by thermal gradient, in individuals compatible with the pattern of normality, and to quantify and describe them anatomically., Methods: The sample consisted of 161 volunteers, of both genders, aged between 26 and 84 years (63 ± 15 years)., Results: The results demonstrated that the thermal gradient areas suggested for the study were present in at least 95% of the thermograms evaluated and that there is significant difference in temperature between the genders, racial group and variables "odontalgia", "dental prothesis" and "history of migraine" (p < 0.05). Moreover, there was no statistically significant difference in the absolute temperatures between ages, and right and left sides of the face, in individuals compatible with the pattern of normality (ΔT = 0.11°C)., Conclusions: The authors concluded that according to the suggested areas of thermal gradients, these were present in at least 95% of all the thermograms evaluated, and the areas of high intensity found in the face were medial palpebral commissure, labial commissure, temporal, supratrochlear and external acoustic meatus, whereas the points of low intensity were inferior labial, lateral palpebral commissure and nasolabial.

The ventral medulla oblongata is critical for cardiorespiratory regulation. Here we review previous literature relating to sites within the ventral medulla that have been identified as having a 'cardiovascular' or 'respiratory' function. Together with the maps generated here, of sites from which cardiovascular and respiratory responses were evoked by glutamate microinjection, specific 'cardiovascular' regions have been defined and delineated. Commonly investigated regions, including the vasopressor rostral ventrolateral medulla (RVLM) and vasodepressor caudal ventrolateral medulla (CVLM), or areas only described by others, such as the medullary cerebral vasodilator area, are included for completeness. Emphasis is given to the caudal medulla, where three pressor regions, the caudal pressor area (CPA), the intermediate pressor area (IPA) and the medullo-cervical pressor area (MCPA), caudal to the vasodepressor CVLM were defined in the original data provided. The IPA is most responsive under pentobarbitone rather than urethane anaesthesia clearly delineating it from both the rostrally located CPA and the caudally located MCPA. The description of these multiple pressor areas appears to clarify the confusion that surrounds the identification of the 'CPA'. Also noted is a vasopressor region adjacent to the vasodepressor CVLM. Apart from the well described ventral respiratory column, a region medial to the pre-Bötzinger is described, from which increases in both phrenic nerve frequency and amplitude were evoked. Limitations associated with the technique of glutamate microinjection to define functionally specific regions are discussed. Particular effort has been made to define and delineate the regions with respect to ventrally located anatomical landmarks rather than the commonly used ventral surface or dorsal landmarks such as the obex or calamus scriptorius that may vary with the brain orientation or histological processing. This should ensure that a region can easily be defined by all investigators. Study of defined regions will help expedite the identification of the role of the multiple cell groups with diverse neurotransmitter complements that exist even within each of the regions described, in coordinating the delivery of oxygenated blood to the tissues.

The authors investigated the influence of pregnancy and gender on the density of trigeminal and sympathetic perivascular nerves in posterior cerebral arteries (PCA) and the reactivity to norepinephrine and calcitonin gene-related peptide (CGRP). PCAs were isolated from nonpregnant, late-pregnant, postpartum, and male rats, mounted and pressurized on an arteriograph chamber to obtain concentration-response curves to norepinephrine and CGRP. Arteries were immunostained for CGRP-, tyrosine hydroxylase-, and protein gene product 9.5 (PGP 9.5)-containing perivascular nerves, and nerve density was determined morphologically. Pregnancy had a trophic effect on trigeminal perivascular innervation (P < .01 vs male); however, this was not accompanied by a change in reactivity to CGRP. Sympathetic and PGP 9.5 nerve densities were not altered by pregnancy or gender, and there were no differences in reactivity to norepinephrine. Together, these results suggest that the increase in trigeminal innervation during pregnancy is more related to nociception than in controlling resting cerebral blood flow.

Pericytes are contractile smooth muscle-like cells that surround descending vasa recta (DVR) and provide their capability for vasomotion. The importance of the medullary pericyte derives from the role of DVR to distribute most or all of the blood flow from juxtamedullary cortex to the renal inner and outer medulla. Physiological processes that are likely to be influenced by pericyte constriction of DVR include the urinary concentrating mechanism and pressure natriuresis. Oxygen tensions in the medulla are low, so that subtle variation of pericyte vasomotion might play a role to abrogate hypoxia and prevent insult to the medullary thick ascending limb of Henle. Known vasoconstrictors of DVR include angiotensin II, endothelins, norepinephrine, acetylcholine, and adenosine. Vasodilators include prostaglandin E2, adenosine, acetylcholine, bradykinin, and nitric oxide., (Copyright 2001 S. Karger AG, Basel)

Unlabelled: Detailed information on the outflow pathway of sympathetic vasoconstrictor fibers to the upper extremity is lacking. We studied the organization of the sympathetic innervation of the forelimb resistance vessels and of the sinoatrial (SA) node in the decerebrated, artificially respirated cat. The distal portion of sectioned individual rami T1-8 and the sympathetic chain immediately caudal to T8 on the right side were electrically stimulated while the right forelimb perfusion pressure (forelimb perfused at constant flow) and heart rate were recorded. Increases in perfusion pressure were evoked by stimulation of T2-8 (maximal response T7: 55 +/- 2.3 mm Hg). Responses were still evoked by stimulation of the sympathetic chain immediately caudal to T8 (44 +/- 15 mm Hg). Increases in heart rate were evoked by the stimulation of more rostral rami (T1-5; maximal response T3: 55.2 +/- 8 bpm). These vasoconstrictor and cardioacceleratory responses were blocked by the cholinergic antagonists hexamethonium and scopolamine. Sectioning of the vertebral nerve and the T1 ramus abolished the vasoconstrictor response. Stimulation of the vertebral nerve and of the proximal portion of the sectioned T1 ramus increased perfusion pressure (69 +/- 9 and 34 +/- 14 mm Hg, respectively), which was unaffected by ganglionic cholinergic block. These data suggest that forelimb resistance vessel control is subserved by sympathetic preganglionic neurons located mainly in the middle to caudal thoracic spinal segments. Some of the postganglionic axons subserving vasomotor function course through the T1 ramus, in addition to the vertebral nerve., Implications: Forelimb vasculature is controlled by sympathetic preganglionic neurons located in middle to caudal thoracic spinal segments and by postganglionic axons carried in the T1 ramus and vertebral nerve. This helps to provide the anatomical substrate of interruption of sympathetic outflow to the upper extremity produced by major conduction anesthesia of the stellate ganglion or spinal cord.

Background and Purpose: The primary goal of these studies was to understand and investigate the capacity of perivascular nerves to influence the tone of human pial arteries and to compare them with other human cephalic arteries, the superficial temporal and middle meningeal., Methods: Responses to electrical activation of intramural nerves and related features of fresh segments of human cephalic arteries-the pial (PA; 478+/-34 microm ID), middle meningeal (MMA; 540+/-41 microm ID), and superficial temporal (STA; 639+/-49 microm ID)-obtained from patients aged 15 to 82 years during surgical procedures were studied on a resistance artery myograph., Results: The PA segment responses to electrical nerve activation and to norepinephrine (NE; 10[-5] mol/L) were 1% and 21% of tissue maximum, respectively, compared with 6% and 34% for the MMA and 14% and 90% for the STA. Tissue maximum was defined as the force increase to 127 mmol/L KCl plus arginine vasopressin (1 microm). All arteries dilated well to acetylcholine. Possible explanations for the PA marginal neurogenic responses were assessed. NE ED50 was 5.4+/-2.2 X 10(-7) mol/L and did not vary with age or diameter. NE responsiveness did not increase in vessels with spontaneous or raised potassium-induced tone. Relaxation to isoproterenol was variable and propranolol did not increase the neurogenic response. Neither N(G)-monomethyl-L-arginine, N(G)-nitro-L-arginine methyl ester, endothelium removal, nor indomethacin consistently influenced the contractions to NE or neurogenic reactivity. The weak PA neurogenic response is in keeping with its poor innervation. As determined by catecholamine histofluorescence, innervation in the PA is sparse, with density increasing in the order PA, MMA, and STA. The incidence of nerve structures in the PA adventitio-medial junction was only 3% of those in the STA, and these were situated more than 3 microm from the closest smooth muscle cell., Conclusions: We conclude that the weak neurogenic response of adult human pial artery reflects its poor innervation and responsiveness to NE, implying that these features are not important in the regulation of its diameter.

We compared conducted vasomotor responses in juxtamedullary microcirculation in normotensive Sprague-Dawley (SD) and spontaneously hypertensive rats (SHR). The goals of the study were as follows: 1) decide whether internephron coupling is facilitated by conducted vasomotor responses; 2) determine whether the magnitude of induced vasoconstriction decreases with increasing distance from the stimulation site; and 3) determine whether the response is stronger in SHR than in SD rats. Microapplication of KCl to the distal afferent arteriole caused local vasoconstriction that was rapidly conducted (speed > 3.0 mm/s) into the cortical radial artery and neighboring afferent arterioles in SD and SHR. The strength of the response was significantly greater (approximately 40%, P < 0.025) in SHR than SD, and the magnitude decreased monotonically with increasing distance from the stimulation site in both strains. Mechanical length constants were similar in SD and SHR (approximately 325 microm), indicating that the signal responsible for the effect decays at the same rate in both strains. We conclude that internephron coupling strength is significantly greater in SHR and that internephron coupling is due to vascular events conducted along the preglomerular vasculature.

Aminergic and cholinergic vasomotor nerves in vessels of the human optic nerve were studied morphologically. Aminergic nerve fibers were observed by the glyoxylic acid method. Cholinergic nerve fibers were observed by light microscopy after acetylcholinesterase staining by the Karnovsky-Roots method and Tago's modified method. In the retrobulbar optic nerve behind the bulbus, aminergic and cholinergic vasomotor nerves were observed to be dense in the central retinal artery and vein and posterior ciliary arteries. A large number of vasomotor nerves were also demonstrated in vessels in the septum of the optic nerve, but they were sparse in pial vessels. Further centrally, a few vasomotor nerves were found in pial vessels of the intracanalicular and intracranial optic nerve, but few were observed in the septum of the optic nerve. At the optic chiasm they were densely distributed in pial vessels.

Microinjection of L-glutamate into a subregion of the gigantocellular nucleus of the rat medulla oblongata significantly lowers arterial pressure. This vasodepressor area, the gigantocellular depressor area, is topographically distinct from other vasoactive areas of the medulla. We sought to determine the efferent projections of the gigantocellular depressor area and compare these to the efferent projections of sympathoexcitatory neurons within the rostral ventrolateral medulla. The anterograde tracer Phaseolus vulgaris-leucoagglutinin was deposited into sites in the gigantocellular depressor area or rostral ventrolateral medulla (pressor area) functionally defined as vasodepressor or vasopressor by microinjections of L-glutamate. Following Phaseolus vulgaris-leucoagglutinin injections into the gigantocellular depressor area, labeled punctuate fibers were seen bilaterally within distinct areas of a number of autonomic regions including the nuclei of the solitary tract, subcoeruleus area, parabrachial complex, the medial medullary reticular formation of the medulla and pons, and laminae 7 and 10 of the thoracic spinal cord. Following deposits into the rostral ventrolateral medulla (pressor area), labeled fibers were seen in many of these same autonomic nuclei; however, efferents from the gigantocellular depressor area to the nucleus of the solitary tract, the parabrachial complex and the reticular formation were medial to rostral ventrolateral medulla (pressor area) efferents to these same areas. These data indicate that neurons within the gigantocellular depressor area and the rostral ventrolateral medulla (pressor area) project to autonomic nuclei throughout the central nervous system and further suggest a heterogeneity of function with regard to autonomic control both within the reticular formation and its efferent targets. In addition, these data support the view that the gigantocellular depressor area may be a novel reticulospinal sympathoinhibitory area.

The complex vasculature of the human nasal mucosa plays an important role in the protection of the lower respiratory airways. It has to react to different external and internal stimuli and is under control of the autonomic nervous system. The aim of our study was to detect the precise localisation of neural structures in human nasal mucosa vessels under physiological conditions. Silver impregnation and histochemical staining techniques only allowed a partial aspect of autonomic innervation. Modern immunostaining methods with antibodies to neuron-specific enolase (NSE) and S-100 protein proved to be better for the demonstration of nerve structures. Tissue samples were taken from inferior turbinates received at mucotomy in 42 patients. After fixation the samples were embedded in paraffin wax and cut into serial sections. Additionally frozen sections were performed. The immunocomplexes were visualised by the avidin-biotin-complex (ABC) or by the alkaline phosphatase anti-alkaline phosphatase (APAAP) technique. A high density of S-100 and NSE immunoreactivity of neuronal and glial components of autonomic innervation could be demonstrated in the vessels of human nasal turbinates. Branching off relatively thick nerve bundles of the lamina propria fibres extended to the adventitia of the arteries near the periost and formed a periarterial nerve plexus. Fibres of this plexus supplied the smooth muscle tissue of the tunica media. Around veins only a few single nerve fibres could be demonstrated. By using immunocytochemical techniques it is possible to correlate the localisation of the classical neurotransmitters and multiple vasoactive neuropeptides with the corresponding innervation structures of the complex vasculature in human nasal mucosa.

The sympathetic vasomotor innervation of the skin of the human hand was studied in 47 subjects who underwent local anaesthetic block of ulnar, median or radial nerves at elbow or wrist levels. Areas of cutaneous anaesthesia were compared with cutaneous territories of paralytic vasodilatation delineated by infrared telethermography. It was found that: (1) during ulnar nerve block the area of vasodilatation matched the area of anaesthesia in all 15 cases; (2) median nerve block induced paralytic vasodilatation which, in 14 of 15 cases, matched the area of cutaneous anaesthesia in median territory, but also extended to the unanaesthetised lateral part of the dorsum of the hand; (3) no vasodilatation developed during radial nerve block in 17 of 18 cases, whereas areas of sympathetic sudomotor paralysis matched the area of radial sensory loss in all 5 subjects in whom sweating function was studied. It is concluded that: (1) the ulnar nerve supplies vasomotor fibres to its cutaneous sensory territory, no less and no more; (2) the median nerve normally provides supplementary vasomotor innervation to the skin of the radial aspect of the dorsum of the hand; (3) the radial nerve supplies sudomotor innervation for the lateral aspect of the dorsum of the hand, but (4) does not normally contribute vasomotor sympathetic fibres to the skin of the hand.

Histochemical, biochemical and electron microscopic studies of vasomotor innervation in onto- and phylogenesis of vertebrates reveal basic trends in evolution of the adrenegric apparatus of the blood vessels. In evolutionary row of animals, together with the development of hemodynamics, constant development of vasomotor innervation takes place, which reveals itself in the increase of the density of the adrenergic plexus and its mediator content. It was demonstrated that nerve-muscle relationships in vascular wall are not constant and depend on the degree of contraction of vascular muscles. Also inconstant are intercellular contacts of plain muscle fibers, their number and total surface being also dependent on the degree of vascular constriction. It is suggested that rearrangement of nerve-muscle and intermuscular relationships within the vascular wall during contraction-relaxation cycle automatically affects functional parameters of the blood vessel and provides for autoregulation purposes.

Adrenergic and cholinergic innervation of frog arteries and veins has been studied histochemically using glyoxilic acid and the method of Karnovsky--Roots. It was shown that the vessels studied differ in catecholamine-containing structures, the intensity of fluorescence of adrenergic nerve endings, the density of nervous plexus and the direction of nerve fibers. It was found that adrenergic innervation is present not only in the arteries, but in the veins as well. Morphometrical analysis indicates that the density of adrenergic plexus per volume unit of vascular wall in the veins investigated is higher than the density of adrenergic nerves in the arteries. This finding suggests that the nervous control of the veins appears in evolution beginning from amphibians, but not from reptiles. It was reliably demonstrated that aorta thoracica and pulmonary artery receive cholinergic innervation, the density of cholinergic plexus in the latter being twice higher than that of adrenergic one.

Unilateral preganglionic cervical sympathetic stimulation in the anaesthetized cat evoked vasoconstriction in both nasal cavities, dependent on stimulation frequency. Vasoconstriction in the contralateral cavity was 15--20% of that of the stimulated side. Similar findings were obtained on unilateral Vidian nerve stimulation. Vasoconstriction evoked in the sympathectomized nasal cavity by stimulating the opposite cervical chain was reduced but not abolished by sectioning the posterior nasal and ethmoidal nerves of the stimulated side. It is suggested that vasoconstrictor fibres reach the opposite cavity either in these nerves or by way of blood vessels, but more likely that sympathetic fibres from these pathways innervate blood vessels which supply both nasal cavities.

The autonomic outflow and sensory structures in the ovary and accessory reproductive organs of the hamster are described by means of specific fluorescence and enzyme histochemical techniques for the demonstration of catecholamine and acetylcholinesterase (AChE), respectively. Sympathetic nerves accompany branches of the major blood vessels in the mesentery of the ovary, oviduct and tubal uterine horn and invest the vascular bed in each of these organs. Vasomotor fibers predominate in the ovary and oviduct, though occasional adrenergic axons supply thecal and interstitial tissues in the ovary and the longitudinal smooth muscle of the oviduct. Fluorescent myomotor axons run in the suspensory ligament and outer myometrial layer of the uterus, but most of the numerous sympathetic and AChE-fibers in the tubal third of the horn supply the intramural and submucosal vascular plexuses. A limited electron microscopic study of the central spiral (preplacental) arteries of the endometrium indicates that the surrounding terminal AChE-fibers are identical to the fluorescent and granular vesicle-bearing adrenergic axons which form neuromuscular junctions with these vessels. Based on the discovery of specialized sensory endings in the walls of the large collecting veins which drain the hamster uterus, a mechanism is proposed to account for the regulation of blood flow through maternal placental vessels which are devoid of an arteriolar neuromuscular apparatus.

Microinjections of sodium glutamate solution (which excites neuronal cell bodies but not axons of passage) into a circumscribed region within the dorsal reticular formation in the rostral medulla oblongata evoked a large increase in arterial pressure due to wide-spread vasoconstriction. In spontaneously breathing animals, glutamate stimulation of the pressor region did not affect respiratory activity and evoked only a very small and transient increase in electromyographic activity of axial skeletal muscles. The pressor response was not reduced by decerebration or decerebellation, indicating that the pathway connecting the dorsomedial pressor region to the spinal sympathetic outflow is intrinsic to the lower brainstem and spinal cord. Anatomical observations in the present study, combined with those from previous studies, indicate that neurons in this region do not project directly to the spinal cord and do not receive direct afferent inputs from the nucleus tractus solitarius. It is concluded that there exists a circumscribed group of vasopressor neuronal cell bodies within the rostral dorsomedial medulla. The anatomical connections of these neurons, however, are markedly different from those of a previously described group of vasopressor neurons in the rostral ventrolateral medulla, suggesting that the two groups may have different functional roles in cardiovascular regulation.

The responses of isolated, perfused uterine arteries from two species of macaques to perivascular nerve stimulation and to vasoactive drugs have been compared with those previously obtained using similar preparations from men. Uterine arteries from nonpregnant monkeys exhibited dilator responses to nerve stimulation and to acetylcholine, and contained few, if any, beta-adrenoceptors. These properties are not shared by the uterine artery of man and cast doubt on the widely held premise that the physiological characteristics of sub-human primates are similar to those of humans.

Maxillary canine pulpar pressure was recorded on anesthetized dogs by means of a small bore cannula threaded into a hole drilled through the lateral surface of the tooth. Vasoconstriction was brought by the electrical stimulation of the cranial cervical ganglion. Vasodilation was induced by stilmulation of the pterygo-palatine ganglion. This vasodilation was inhibited by atropine. Most often, constrictor fibres follow the course of the pterygo-palatine nerve, when dilator fibres follow the infraorbital nerve. However, both sorts of fibres may be found in the infraorbital nerve.

Dual innervation of snake cerebral blood vessels by adrenergic and cholinergic fibres was demonstrated with the use of histochemical methods. Although the nerve plexuses are somewhat less dense, the essential features of innervation of the blood vessels are similar to those of mammals with the exception that the adrenergic plexuses are more prominent than the cholinergic plexuses. The major arteries of the cerebral carotid system have a rich nerve supply. However, the innervation is less rich in the basilar and poor in the spinal (vertebral) arteries. Although the arteries supplying the right side of head are poorly developed, three pairs of arteries, cerebral carotids, ophthalmics and spinals, supply the snake brain. The carotids and ophthalmics are densely innervated and are accompanied by thick nerve bundles, suggesting that the nerves preferentially enter the skull along those arteries. Some parenchymal arterioles are also dually innervated. Connection between the brain parenchyma and intracerebral capillaries via both cholinergic and adrenergic fibres was observed. In addition cholinergic nerve fibers, connecting capillaries and the intramedullary nerve fibre bundles, were noticed. Capillary blood flow may be influenced by both adrenergic and cholinergic central neurons. The walls of capillaries also exhibit heavy acetylcholinesterase activity. This may indicate an important role for the capillary in the regulation of intracerebral blood flow.

Based on wheat germ agglutinin-conjugated horseradish peroxidase histochemistry in Sprague-Dawley rats, we identified a reciprocal and bilateral connection between the nucleus reticularis rostroventrolateralis (NRRVL) and the nucleus ambiguus. The rostral ventrolateral medulla also received bilateral inputs from the nucleus reticularis gigantocellularis (NRGC) and nucleus reticularis medullae oblongatae, a projection from the caudal ventrolateral medulla, and had a close relationship with the NRGC pars lateralis. Thus, apart from its well-established projection to the spinal sympathetic preganglionic neurons and innervation from the nucleus tractus solitarius, the NRRVL may also have rich connections with many medullary sites that participate in cardiovascular regulations.

The anteroventral third ventricle (AV3V) region is necessary for the development of a variety of models of experimental hypertension. Neuroanatomic studies have identified descending projections from this region to the mesencephalic central gray and tegmentum. This study was done to identify functionally the projections involved in cardiovascular regulation from the AV3V region to the mesencephalon. Regional hemodynamic responses to electrical stimulation of the AV3V region were compared with responses to stimulation of the rostral central gray, and these responses were compared before and after ablation of mesencephalic tissue. Stimulation of the AV3V region elicited hindquarter, vasodilation and renal and mesenteric vasoconstriction associated with a depressor response and bradycardia. These responses were partially dependent on adrenal catecholamines since adrenalectomy reduced hindquarter, mesenteric, and depressor responses. Regional hemodynamic responses to central gray stimulation were qualitatively similar and also demonstrated a partial dependence on adrenal catecholamines. After electrolyte ablation of central gray tissue, significant reductions in hindquarter, mesenteric, and depressor responses to AV3V stimulation were observed. These observations suggest that a cardiovascular control system important for the development of several models of hypertension may be dependent on neuronal projections from the rostral medial hypothalamus through the mesencephalic central gray.

We examined two functionally and anatomically distinct subregions of rostral ventral medulla, rostral ventrolateral medulla (RVLM, 2 mm lateral to midline) and an area we term rostral ventromedial medulla (RVMM, 1mm lateral to midline). Reducing tidal volume attenuated the depressor response to microinjection of lidocaine (200nl, 4%) into RVLM, but not into RVMM. Lidocaine reduced renal (RVR), mesenteric (MVR), and hindquarter (HQVR) vascular resistances, when injected into both sites, however HQVR was markedly reduced when RVMM was blocked. Selective stimulation with microelectrodes increased RVR, MVR, and HQVR, with RVMM producing the strongest response in HQVR and RVLM the strongest effect on RVR. Cardiovascular responses to stimulation of RVLM required the integrity of RVMM, however, the converse was not found. The integrity of RVMM, but not RVLM, was required for the cardiovascular responses produced by electrical stimulation of lateral hypothalamus. Together, these data suggest that RVLM and RVMM are both important for tonic regulation of vasomotor tone, however, these sites differ in their responses to afferent input and in the control of regional vascular resistances.

Retrograde dye staining, enkephalin immunocytochemistry and nerve lesion paradigms were used to determine if penile neurons in the pelvic plexus are innervated by fibers in the hypogastric nerve. In the intact major pelvic ganglion of the rat, some 80% of penile neurons are enclosed by an enkephalin-positive fiber plexus. Following surgical interruption of the pelvic nerve, 20% of penile neurons were still surrounded by an enkephalin plexus. After interruption of the pelvic nerve and the hypogastric nerve, the enkephalin plexus in the ganglion was virtually absent, including the plexus around penile neurons. Therefore, possible intrinsic sources of the enkephalin fibers such as enkephalin-positive principal neurons and small intensely fluorescent cells, do not account for the delicate enkephalin fiber system in the pelvic ganglion. It is concluded that the pelvic nerve is the major source of preganglionic innervation to penile neurons in the major pelvic ganglion. However, it is significant that the hypogastric nerve is preganglionic to about 20% of penile neurons. The pathway through the hypogastric nerve may represent an alternate vasodilator system to penile erectile tissue.

We sought to establish whether neurons of the C1 area of the rostral ventrolateral medulla (RVL) mediate changes in arterial pressure and heart rate evoked by topical application of drugs to the ventral medullary surface of the rat. Animals were anesthetized, paralyzed, and ventilated. The ventral surface was mapped with L-glutamate, and a restricted zone was identified from which L-glutamate, as well as kainic acid, bicuculline, strychnine, carbachol, or physostigmine, increased arterial pressure and heart rate. The hypertensive effects of carbachol and physostigmine were blocked by previous local application of atropine but not hexamethonium. Application of gamma-aminobutyric acid (GABA) or glycine to this area produced hypotension and bradycardia. Located caudal to the trapezoid bodies and lateral to the pyramids, this area corresponded to points with lowest threshold for pressor responses evoked by electrical stimulation and overlapped the distribution of epinephrine-synthesizing cells of the RVL. Processes arising from these neurons were identified reaching and contacting the ventral surface. Unilateral lesions involving the C1 area or phenylethanolamine-N-methyltransferase-labeled descending axons derived from this area imparied by greater than 70% the response to ipsilateral application of L-glutamate, GABA, or glycine to the ventral surface. We suggest that neurons within the C1 area of RVL adjacent to or including epinephrine cells may mediate cardiovascular changes elicited from a restricted chemosensitive zone of the ventral medullary surface of the rat.

In anesthetized cats, the cold block or coagulation of intermediate zones of the bulbar ventro-lateral surface (BVLS) resulted in profound decrease of the blood pressure (BP) level. The descending tonic activation of spinal vasomotor mechanism in formed by spontaneous discharges of antidromically identified output sympatho-activating neurons with mean firing rate about 14.4/sec. After coagulation of the intermediate zone, pressure reflexes of the BP and late somato-sympathetic response in white rami disappear whereas the spino--bulbo--spinal somato--somatic reflex remains unchanged. The reflex discharges of single sympatho--activating neurons were within the time limits of the late somato--sympathetic response and followed by the silent period. The preferable inhibition of the long-latency white rami discharges elicited by BVLS stimulation arise 200-250 msec after R-wave of the ECG. The inhibition of long-latency discharges was observed during the increase of the BP level induced with vasoconstrictor drugs. The intermediate zone structures of BVLS seem to play the key role in supporting of the BP level and organization of pressure reflexes. These structures are suggested to be the actual elements of the bulbar vasomotor center.

The authors sum up the anatomical aspects of the arteries of the hand. They emphasise the fact that, by the side of the classical description; there is a lot of variations. These can be explained by organogenesis, showing that hand arteries pass over several stages, before reaching the terminal one. Generally, it seems that the classical diagram correspond to the majority of cases, and that there is a main flow for hand's arteries: this are the superficial and deep arches, which give common and proper digital arteries. About the innervation, this structures are very richly innervated, but this sympathetic innervation is not so precisely delimited in its topography, and for that reason, its seems to be difficult to give an clear diagram of its origin and distribution. That can explain surgical treatment's failure in vasomotor syndromes of upper limbs.

The projections of the retrofacial portion of nucleus paragigantocellularis lateralis (retrofacial PGCL) were mapped in the rat with the Phaseolus vulgaris leucoagglutinin anterograde tracing technique. This structure projects to a restricted number of bulbar or spinal nuclei involved in autonomic regulation, principally the intermediolateral cell column of the spinal cord, the nucleus tractus solitarius complex, the lateral parabrachial and Kolliker-Fuse nuclei and the ventrolateral medulla. Retrofacial PGCL also densely innervates the locus coeruleus. This projection originates in large part from phenylethanolamine-N-methyltransferase-immunoreactive cells (C1 adrenergic cluster) as demonstrated by immunohistochemistry combined with the retrograde transport of rhodamine-tagged microbeads. A very small suprabulbar projection of retrofacial PGCL was also detected in some cases.

The sympathetic nerve pathways to the nasal vasculature were examined in 8 cats by recoding the effects of section of the orbital nerves on vasoconstriction produced by cervical sympathetic nerve stimulation. No sympathetic fibres were found in the sphenopalatine and infraorbital nerves. The majority were conveyed by either the Vidian or ethmoidal nerves, the remaining fibres are believed to reach the nasal cavity by the periarterial plexus.

Analysis of the arterial pressure responses to electric stimulation of the spinal cord structures at T1 to L3 showed two zones of the maximal pressure activity in the lateral and medial parts of the lateral funiculus. After destruction of the lateral part at T1-T2 level, a decrease in the systemic arterial pressure occurred after stimulation of the pressor zone of the vasomotor center and structures of the spinal cord at the levels of C5 and ischiatic nerve. These and previously obtained data suggest that the pressor responses to stimulation of the lateral part of the lateral funiculus of the spinal cord are of the reticulospinal origin. Participation of the propriospinal fibers in the pressor responses to stimulation of the medial zone of the lateral funiculus is discussed.