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The quality and storability of iceberg lettuce (Lactuca sativa L.) is dependent on growing and storage conditions, which are not completely known. Lettuce was planted at approximately monthly intervals from Sept. 2006 to Feb. 2007. Crops were harvested at approximately monthly intervals from Nov. 2006 to May 2007 and held in storage at 3 and 13°C. Effects of harvest month and storage condition on storage quality—i.e., changes in textural quality, sugar and organic acid contents—as well as shelf-life in iceberg lettuce were examined. Higher values for puncture force and breaking energy and increased sugar content were found in the cooler than in the warmer months. Lower leaf crispness was recorded after one week of storage with a greater degree at 13°C. Total soluble sugar content declined by about 56% and 32% after one week of storage at 13°C in the outer and inner leaves, respectively. Organic acid content did not show any consistent trend. At the end of the harvest season, shelf-life declined by 40% and...

The changes in ammonia content as well as activity and gene expression of glutamate dehydrogenase (GDH; EC 1.4.1.2) were investigated in lettuce during storage. GDH amination activity increased with the increases in ammonia content in the outer leaf portion after 24 h of storage. GDH amination activity was substantially higher than deamination activity. The isolated partial cDNA clone referred to as LsGDH (Lactuca sativa glutamate dehydrogenase; AB334207) consisted of 757 nucleotides and was highly homologous with the GDH genes of other plants. Although the transcript of LsGDH was found in both the outer and inner leaves, the level of transcript gradually increased in the outer leaves with the progress of storage, but was only expressed in the inner leaves when higher enzyme activity was observed. Results suggest that GDH expression in lettuce is controlled by tissue specific manner and/or multiple levels of regulations.

The influence of the neonatal frontal lesion in unilateral cerebral hemisphere for the organization of intact forelimb motor cortex in the rat was investigated by intracortical microstimulation (ICMS). The relative size of the rostral forelimb area (RFL) compared to the caudal forelimb area (CFL) in the ipsilateral motor field of lesioned rat was significantly greater than those of contralateral in normal and lesioned rats. The optimal sites of the stimulation for ipsilateral responses in lesioned rats were located in the RFL, while the optimal sites for contralateral were located caudolaterally, as for those of normal rats. At the ipsilateral optimal sites within the RFL in the lesioned animals, the threshold for the ipsilateral responses was lower than that for the contralateral responses. That is, the intact hemisphere of the animal preferentially developed the RFL rather than the CFL, for the ipsilateral forelimb. This may suggest a critical role for the RFL in individual forelimb motor control within the normal hemisphere.

1. We developed a new kind of food search test that can measure murine nocturnal memory without handling hard work for setting up. 2. This apparatus has four food stations, but only one station had accessible food at any time. The one station with accessible food was changed at 4-h intervals. 3. We compared the performance of transient forebrain global Ischemic mice, which are a hippocampal lesion model, with the performance of control C57BL/6J mice. 4. The correct visit ratio, i.e., the ratio of the number of visits to the correct food station to the number of visits to all stations, gradually increased in the control mice, but did not change in the Ischemic mice. 5. This new system was demonstrated to be an additional and useful tool for studying memory-related performance in mice.

Nymphs ofNilaparvata lugens were experimentally reared from the 2nd instar in a cage covering part of the leaf sheath of an individual rice plant grown in a Wagner pot. Plants were covered with the cage from the water surface of the pot to 10 cm above the surface (lower cage-group) or from 10 cm to 20 cm above the surface (upper cage-group). Temperatures measured at three different parts of the cage remained fairly constant in both groups at around 25°C (23.7–25.2°C in mean value). In the lower cage-group, relative humidities measured at the three heights in the cage in (76.3–90.5% in mean value) markedly increased with the approach to the water surface. The nymphs of this group, particularly during the molting period, aggregated close to the surface. Eighty-two percent of the released nymphs emerged in this group. Relative humidities measured at three heights of the upper cage-group were 69.5–72.7% in mean value, and all the nymphs in this group died within 3 days after their release although half of them stayed on the rice plants within 6 h after their release. The role of relative humidity as a limiting factor on the range of the microhabitat and the population density ofN. lugens in rice fields was discussed on the basis of the results.

Action of habenular efferents on neurons of the ventral tegmental area (VTA) was studied with a slice preparation that preserved the habenula (Hb) and the VTA together with the interconnecting fiber bundle, the fasciculus retroflexus (FR). In the VTA, two types of neurons, presumably corresponding to the dopaminergic and nondopaminergic neurons, were discerned on the basis of the electrophysiological properties. Of 52 VTA neurons sampled, 42 [with the mean resting membrane potential of 56 ± 7 mV (mean ± SD)] responded with excitatory postsynaptic potentials (EPSPs) to FR stimulation. The EPSPs were monosynaptic in nature and rather weak in effect in the sense that they rarely triggered spikes. No significant differences in latency, duration and time to peak were noted between the EPSPs generated in different types of neurons. FR stimulation evoked inhibitory postsynaptic potentials (IPSPs) in only six neurons, their resting membrane potential being 51 ± 4 mV. The IPSPs frequently showed a fluctuation in latency. FR stimulation also produced antidromic responses in a few VTA neurons, but their long latencies precluded the possibility that the VTA-Hb projections contributed to the FR-evoked orthodromic responses in the VTA. EPSPs evoked by FR stimulation could be suppressed by kynurenic acid (1 mM). The findings indicate that the efferents of the Hb primarily have an excitatory effect on VTA neurons of any type and that the excitation may be mediated by amino acid receptors.

Objective: Acute corneal permeability change after instillation of benzalkonium chloride (BAC) was evaluated using a newly developed in vivo corneal transepithelial electric resistance (TER) measurement method. Method: Corneal TER was measured by Ag/AgCl electrodes placed in the anterior aqueous chamber and on the cornea of live rabbit eyes. TER was measured and TER change after instillation of 0.05% BAC solution was monitored. After TER measurement, cornea was excised and fixed for transmission and scanning electron microscopy. For the control study, physiologic saline was used instead of BAC. Results: The TER of normal rabbit cornea was 602.3 ± 195.0 Ωcm2. TER decreased instantly after instillation of 0.05% BAC. In 5 s, TER decreased to 58.3 ± 5.2%. In 60 s, TER decreased to 18.5 ± 3.2%. At all time points, TER after instillation of 0.05% BAC was significantly lower than that of the control (p < 0.0001). Dissociation of tight junctions and the destruction of superficial cell membranes were observed under electron microscopy. Conclusion: Corneal epithelial change with increased permeability is rapid and intense after the instillation of highly concentrated BAC solution, accompanied by disorder of tight junctions and cell membranes of superficial cells. The newly developed in vivo corneal TER measurement method is suitable for assessing acute corneal change after drug instillation.

To investigate the neural mechanisms underlying the mammalian photic entrainment of circadian rhythms, the response of neuronal extracellular firing activity to retinal light stimulation was investigated in the suprachiasmatic nucleus (SCN) of anesthetized mice during nighttime and daytime. In nighttime, most recorded SCN cells (83%) increased their firing frequency in response to retinal illumination. Some SCN cells (11%) responded by decreasing their firing rate. In daytime, the retinal illumination increased the firing rate in only 26% of the SCN cells, and no response was observed in the remaining cells. The light intensity threshold for the activation of SCN cells at zeitgeber time (ZT) 16 was approximately 3 × 10 11 photons cm −2 s −1 and the maximum response was observed at approximately 1 × 10 14 photons cm −2 s −1 . Therefore, photic response in the firing of mouse SCN cells may be phase-dependent and have a higher threshold, which corresponds to properties of the photic entrainment in locomotor activity of mice.

1. We developed a new kind of food search test that can measure murine nocturnal memory without handling hard work for setting up. 2. This apparatus has four food stations, but only one station had accessible food at any time. The one station with accessible food was changed at 4-h intervals. 3. We compared the performance of transient forebrain global Ischemic mice, which are a hippocampal lesion model, with the performance of control C57BL/6J mice. 4. The correct visit ratio, i.e., the ratio of the number of visits to the correct food station to the number of visits to all stations, gradually increased in the control mice, but did not change in the Ischemic mice. 5. This new system was demonstrated to be an additional and useful tool for studying memory-related performance in mice.

The present work demonstrates that the cortical reactivity of the rat, monitored by thalamocortical responses, can be enhanced by repetitive transcallosal volleys (5-20 Hz). This effect can be completely inhibited by callosotomy. We believe that the interhemispheric epileptogenesis and the suppressive effect of callosotomy for intractable epilepsy can be explained by this facilitatory effect of the corpus callosum on the cerebral cortex.

On stimulation of the medial prefrontal cortex (mPFC) of the rat, the amygdala neurons projecting to the mPFC exhibited an IPSP, which caused IS-SD blockage in the antidromic spikes of these neurons. The IPSP was not preceded by EPSP, but was not monosynaptic in nature. Its onset latencies were mostly confined to within 10 ms, which was shorter than the time for orthodromic conduction from the mPFC to the amygdala. The findings indicated that the IPSP was produced via recurrent collaterals of the amygdalo-cortical projection neurons. In view of the wide range of distribution of the time for antidromic conduction in the amygdalo-cortical projection neurons (3.4-27.2 ms), the projection neurons with a fast-conducting axon were considered to be responsible for the mPFC-evoked recurrent IPSP.

Responses generated in the prelimbic-infralimbic cortices (areas 32 and 25) by stimulation of the basolateral amygdala were studied by means of laminar field potential recordings. Based on the analysis of wave forms and depth potential profiles of the responses, three constituent responses were identified: (1) a surface-positive potential with a short onset latency (mean, 4.5 ms) and a long duration (ca. 70 ms) that reversed the polarity at a depth of 400 microns; (2) a surface-positive potential with a mean onset latency of 15 ms and a duration of 20 ms that reversed to a negative potential at a depth of 300 microns; and (3) a long-latency (ca. 20 ms) superficial-negative potential that reversed to a positive potential at depths below 400 microns. Lesion experiments ruled out the possibility that impulse traffic via the thalamic mediodorsal nucleus (MD) contributed to the responses. Amygdala stimulation also produced responses in the insular cortex, but they did not contaminate the responses in the mesial cortex. It is proposed that impulses originating from the amygdala provide excitation for cortical pyramidal cells at a short latency at deeper layers, but with considerable delays at upper and superficial layers, in the medial prefrontal cortex (mPFC).

The quality of The Journal of Headache and Pain depends on the qualified and regular collaboration of renowned scientists, who devoted their time to constructively review the submitted articles. We are indebted to the following experts who reviewed papers that completed the peer-reviewing process within 2014. M.A. Al-Jumah (Riyadh) A.P. Andreou (London) A. Antal (Gottingen) F. Antonaci (Pavia) R. Arcioni (Rome) A. Ashkenazi (Doylestown) M. Ashina (Copenhagen) S. Ashina (New York) T. Bartsch (Kiel) E. Beghi (Milano) A.C. Belin (Stockholm) L. Bendtsen (Copenhagen) R. Benoliel (Jerusalem) L. Berliocchi (Catanzaro) M. Bjorn Russell (Oslo) A. Bozzao (Rome) Correspondence: valerio.deangelis@uniroma1.it Assistant to the Editor, The Journal of Headache and Pain, Via di Grottarossa 1035, 00189 Rome, Italy © 2015 De Angelis; licensee Springer. This is an Attribution License (http://creativecommons.or in any medium, provided the original work is p F. Brighina (Palermo) O. Bruni (Rome) J.M. Bugnicourt (Amiens) R. Cady (Springfield) L. Cao (Biddeford) S. Ceruti (Milan) S. Cevoli (Bologna) A. Charles (Los Angeles) T.C. Chaves (Ribeirao Preto) G. Coloprisco (Rome) G. Coppola (Latina) S. Cortese (Verona) C. Costa (Perugia) M. Davis (Rochester) M. de Tommaso (Bari) C. Di Lorenzo (Latina) V. Di Piero (Rome) Open Access article distributed under the terms of the Creative Commons g/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction roperly credited. De Angelis The Journal of Headache and Pain (2015) 16:16 Page 2 of 3 H.C. Diener (Essen) A. Donnet

Two types of neurons were differentiated, on the basis of electrophysiological properties, in the substantia nigra pars compacta of the guinea pig maintained in slices. While the majority of neurons, presumably dopaminergic neurons, produced a broad spike accompanied by a relatively long-lasting after-hyperpolarization, a small number of neurons were characterized by the generation of a depolarizing after-potential (DAP) following a fast spike. The DAP was depressed by a slight depolarizing shift of the resting membrane potential and by the removal of Ca2+ from the bathing medium, which suggested that it was a low-threshold Ca2+-dependent response. Intracellular staining revealed that the neurons producing DAP were smaller than the major neurons.

Effects of quinidine (25 microM-1mM) and its stereoisomer, quinine (1-5 mM), on the excitability of CA3 pyramidal neurons were investigated in guinea-pig hippocampal slices using intracellular recording techniques. At concentrations of quinidine higher than 100 microM (and higher than 1 mM for quinine), 1) the resting potential shifted to the depolarizing direction with an increase of the input resistance, 2) the spike duration was prolonged, 3) the spike amplitude was decreased, 4) the late component of the afterhyperpolarization (AHP) (caused by the activity of the Ca2+-mediated K conductance) were suppressed, and 5) finally, neurons became inexcitable. The results indicate that the blocking action of quinidine and quinine is not specific to the Ca2+-mediated K conductance in mammalian hippocampal neurons, and that this conductance is much less sensitive to the drugs in comparison with other preparations.

The response to ramp current stimulation was studied in the pars compacta neurons in guinea pig substantia nigra slices. Although accommodation was not seen with current duration up to 1000 ms, a threshold peak emerged on the threshold-latency curve at 30-400 ms when the cell was hyperpolarized. The appearance of the peak was closely correlated with an inflection in the potential trajectory before the spike. A voltage-dependent, fast inactivating outward current may underlie these responses. They persisted in Ca2+-free solution, but disappeared when Cd2+ (0.4 mM) or Co2+ (5 mM) ions were applied extracellularly.

In guinea pig hippocampal slices, 4-aminopyridine (4-AP) in concentrations of 100-500 microM reduced the adaptation of CA3 pyramidal neurons to depolarizing stimuli, resulting in a prolongation of repetitive firing during injection of long-lasting depolarizing currents. Concurrently, there was a decrease in the 'sag' of potential after spike bursts. Furthermore, 4-AP decreased or abolished the hyperpolarizing potential (the afterhyperpolarization) which normally followed repetitive firing of the neurons. The findings suggest that 4-AP could interfere with the Ca2+-activated K+ current in hippocampal CA3 pyramidal neurons.