In order to study the mechanisms of high frequency stimulation ( HFS), we designed an in vitro device to deliver extracellular electrical stimulation to live cells in culture, using the same parameters as in the surgical treatment of Parkinson's disease (PD). The system was made of a 24 wells culture plate electrified with titanium wire bridges or two titanium wires placed parallel in a culture dish of 10 centimetres diameter. The extremities of the series of wells were connected to a constant current generator. The result showed that this system had no toxicity on GH3 and PC12 cell cultures. Preliminary experiences demonstrate that this system is suitable for the study with DNA and protein chip technologies.

In this study, we treated transgenic Huntington's disease (tgHD) model rat with deep brain stimulation (DBS) and evaluated the cognitive and motor outcome. The results showed that the surgery of implanting electrode improved cognition, increased correct rate and decreased response bias in choice reaction time (CRT) task, with similar extent on various genotypes. After long-term DBS to globus pallidus externa( GPe), correct rate was enhanced. The enhancement was genotype related. Additionally, the motor time and reaction time in CRT task reflecting the movement initiation kept the same value, but the chorea-form movement of homozygous rats was rectified prominently after the treatment of DBS. The present results demonstrated that the operation of long-term DBS to globus pallidus externa can improve the cognition and motor outcome of tgHD rats, which implied DBS operation might shed light on HD patients in the future.

The neurochemical features of the nitrergic and peptidergic innervation of the porcine esophagus were investigated by means of immunohistochemical methods combined with vagotomy. Neuronal cell bodies in both the submucosal and the myenteric plexus (MP) were detected immunoreactivities for nNOS, VIP, GAL, NPY, PACAP, L-ENK, SP, 5-HT and CB, while CGRP- and SOM-immunoreactive (ir) somata were not encountered. In addition, nNOS- and CB-ir myenteric neurons constituted the separate enteric subpopulations.Double immunostainings with a general neuronal marker (PGP9.5 ) and the specific markers, such as nNOS, VIP and SP revealed (1)nNOS-ir myenteric neurons in the porcine esophagus accounted for a higher percentage (63 % ) of all esophageal intrinsic PGP9.5-ir neurons in comparison of VIP-ir (36%) and SP-ir populations (28%); (2) An increasing rostrocaudal gradient in the number of myenteric neurons per ganglion as well as a significantly higher number of enteric ganglia within both plexuses in the abdominal segment; ( 3 ) The densest nerve fibers within the esophageal musculature were VIP-/GAL-/NPY-ir, some of which also co-expressed nNOS and/or PACAP immunoreactivity. The number of L-ENK- and/or SP-ir fibers was significantly higher in lamina muscularis mucosae ( LMM ) than in tunica muscularis externa (TME). In contrast to reports in other species, CGRP-ir fibers within the porcine esophagus constituted a very limited population and were extrinsic; (4) Vagotomy experiments revealed an obvious decrease of PACAP-and 5-HT-ir nerve fibers within the MP,suggesting that these fibers originate from the vagal nerve, while these nNOS- and/or VIP-/GAL-/NPY-ir fibers innervating both the TME and the LMM did not appear to be significantly affected by the vagotomy procedure, possibly being the intrinsic origin.

In order to characterize the neurochemical features of nitrergic myenteric neurons in the rat esophagus and to disclose some possible cause of nitrergic neuronal cell loss in the rat esophagus during aging, whole-mount preparations from different esophageal segments of different age- and strain-groups were studied by double immunohistochemistry of neuronal nitric oxide synthase (nNOS) and calbindin (CB). We found for the first time co-localization of nNOS and CB in myenteric neuronal bodies with a specific distribution pattern along the entire length of rat esophagus: significantly higher percentage of nNOS/CB immunoreactive (ir) myenteric neurons (ca 30%-40%) were found in the abdominal segment in comparison with the other segments of the organ (P<0.001). Nitrergic myenteric neurons in the rat esophagus could be subdivided at least into two groups: nNOS+/CB+ and nNOS+/CB-. Moreover, the majority of CB-ir myenteric neurons,especially in the abdominal esophagus expressed nNOS-ir (ca 95%-100%). All these features were persisted in all age and strain groups of rats studied. The relative percentages of the nNOS-/CB-ir neurons among the total nitrergic population varied strain-dependently during aging. Regression analysis yielded a significant negative correlation between the percentage of nNOS-/CB-ir neurons found in the young Sprague-Dawley rats and percentage of nitrergic neuronal loss during aging (correlation coefficient 0.99; P< 0.05). However, the functional significance of the regional differences in nNOS-/CB-ir neurons along the rat esophagus remains to be elucidated.

Extracellular single-unit discharge recording technique was used to examine the effects of Ginkgolide B (BN52021) on the discharges of neurons in CAI area of hippocampal slices and to elucidate the mechanisms involved.The results showed that:(1) In response to the application of ginkgolide B (0.1,1,10 βμmol/L; n =43) into the perfusate for 2 rain,the spontaneous discharge rates (SDR) of 42/43 (97.67%) neurons were significantly decreased in a dose-dependent manner; (2) Pretreatment with L-glutamate (L-Glu,0.2mmol/L) led to a marked increase in the SDR of all 10 (100%) neurons in an epileptiform pattern.The increased discharges were suppressed significantly after ginkgolide B (1 μmol/L) was applied into the perfusate for 2 rain; (3) In 8 neurons,perfusion of the selective L-type calcium channel agonist,Bay K 8644 (0.1 μmol/L),induced a significant increase in the discharge rate of 8/8 (100%) neurons.Ginkgolide B (1 μmoL/L) applied into the perfusate inhibited the discharges of 7/8 (87.5%) slices; (4) In 8 neurons,the broad potassium channels blocker,tetraethylammonium (TEA,1 mmol/L) completely blocked the inhibitory effect of ginkgolide B (1 μmol/L).These results suggest that ginkgolide B can inhibit the electrical activity of CAI neurons.The inhibitory effect may be related to the blockade of L-type voltage-activated calcium channel and may be concerned with delayed rectifier potassium channel (KDR),which indicated that ginkgolide B play a protective role on the central neurons.

Previous studies showed that the Vodm-LRF-including the dorsomedial part of the subnucleus oralis of the spinal trigeminal nucleus and its adjacent lateral reticular formation--contained the second-order neurons on the central pathway of the trigeminal proprioceptive sensation of the rat and the "zone-shaped area"-including the caudolateral part of the supratrigeminal nucleus (Vsup-CL). The dorsomedial part of principal sensory trigeminal nucleus (Vpdm) and two newly found nuclei: the areaventral to the motor trigeminal nucleus (AVM) and the area dorsal to the superior olivary nucleus (ADO)-contained the third order neurons of this pathway. Parvalbumin (PV) is one of the calcium-binding proteins, In this pathway, many PV-like immunoreactive (PV-LI) neurons were observed in Vodm LRF and the "zone-shaped arena", hut there has been no reports so far regarding whether these PV-LI neurons are projection neurons responsible for the transmission of proprioceptive information or the interneurons serving the modulatory function, in the present study, our aim was to solve the problem by a double labeling study by using retrograde tracing method combined with immunofluorescence histochemistry. The results showed that: (1) following the unilateral Fluoro-Gold (FG) injections into the ventral posteromedial nucleus (VPM) of the thalamus and the separated parts of the "zone-shaped area", viz, Vpdm, ADO and AVM, many FG-labeled neurons were always found contralaterally in the "zone-shaped area" and ipsilaterally in the Vodm-LRF, respectively; (2) in either the "zone-shaped area" or the Vodm-LRF, a substantial number of the FG retrogradely labeled neurons showed PV-LI. In the Vsup-CL, Vpdm, AVM and ADO, about 57%, 55%, 11% and 4% of the neurons projecting to the VPM of the thalamus showed pV-LI, respectively. Of the total population of PV-LI neurons in the Vsup-CL, Vpdm. AVM and ADO, about 23%, 79%, 53% and 16% were labeled by FG, respectively. Most of these PV/FG double-labeled neurons were medium- to small-sized, round, piriform or irregular in shape. On the other hand, in the Vodm-LRF, approximately 33%, 34% and 50% of the neurons which projected to the Vpdm, AVM and ADO expressed PV-LI, respectively. The percentage of PV/FG double-labeled neurons to the total number of the PV-LI neurons in Vpdm, AVM or ADO were 26%, 17% or 11%, respectively, The present results indicated that PV might play an important role in the transmission of the trigeminal proprioceptive information of the rat from Vndm-LRF to the contralateral VPM of the thalamus through the "zone-shaped area".

It has been known that the Alzheimer's disease(AD)is related closely with a synaptic failure,and the p21-activated kinase(PAK)is well documented to play an important role in the regulation of the synaptie functions.However,the relationship between thePAK and the pathology of AD is unclear.In the present study,we examined the expressions of the PAK3(one subtype ofPAK),phospho-rylated-PAK(pPAK) and β-amyloid42(Aβ42,β-amyloid with 42 peptides)in an APP/PS1 double transgenie mouse model of AD andthe morphologies of geurOtlS in the hippocampus at different ages.The Western Blot results showed that the expression of PAK remainedunchanged,while,the expression of pPAK decreased largely at the age of 32 weeks and further decreased significantly with aging in thehippocampus of the APP/PS1 transgenic mouse.A1342 levels in the hippocampus were detected to increase as early as the age of 22 weeks,and kept the increase to continue with aging.The morphological results showed no obvious neuron loss in the sections of Nissl staining,while serious distonion and disorder of the dendrites of the hippocampal neurons were observed on the sections of Gelgi staining in theAPP/PS1 transgenic mouse.The present results suggested that it seemed something wrong in the processes of phospholization of PAK,butnot in the expression of the PAK itself;the toxic Aβ42 might affect the PAK in its phospholization,which in turn directly influence thedendritic development in the hippocampal neurons and cause the dendrites distorting and disordering.

To investigate whether HIV3B and HIV Ada-M can infect cultured human dorsal root ganglion (DRG) neurons, organotypic and dissociated human fetal DRG cell culture models were established. On the 14th day, organotypic cultured DRG explants were exposed to HIV3B or HIV Ada-M for another 14 days. Outgrowth and morphology of neurites were observed with phase contrast microscope at different time of cultured age. On the 3rd day, dissociated cultured DRG cells were exposed to HIV3B or HIV Ada-M for another 3 days. After that, dissociated DRG cells were processed for microtubule-associated protein 2 (MAP2) labeling and observed with fluorescent microscopy. DRG explants on the 28th day and dissociated DRG cells on the 6th day, the samples were processed for electronic microscopic observation. Both organotypic and dissociated DRG cultures were cultured continuously in culture media as controls. Immature HIV-like particles were found in organotypic cultured DRG neurons. Many HIV-like particles were found in dissociated cultured DRG neurons. HIV infection could not cause morphological and ultrastruc( )l alterations on both organotypic and dissociated cultured DRG neurons. These discoveries will be valuable for studies on pathogenic (mee)hanisms of HIV infection and/or HIV associated peripheral neuropathies.

With the aim to examine the distribution of high-affinity neurotrophin receptors (tyrosine kinase receptors, TrkA, TrkB and TrkC)in the rat Scapa's ganglion ( vestibular ganglion, VG), Avidin-Biotin-peroxidase Complex ( ABC ) method of immunohistochemistry with diaminobenzidine (DAB) as the chromogen to identify the immunoreactivities was employed in the present study. The results showed that many VG neurons were immunoreactive to each Trk isoform. The receptors were localized in the neuronal somata. The intensity of immunoreactivity for each Trk receptor was different among neurons, ranging from weak, moderate to intense. For each individual Trk receptors, the labelled neurons were of different size; the result sfatistical of analysis showed that the mean areas for neurons immunoreative to TrkA, B and C were 330.8 ± 7.6, 303.89 ± 10.6 and 355.05 ± 8.3 μm2 , respectively. The present study provids morphological substrate for the important roles played by Trk receptors in maintaining the survival and stabilizing the phenotype of VG neurons.

The structure and 5-HT immunoreactivity in the brain and suboesophageal ganglion of three beetles, Ambrostoma quadriimpressum, Henosepilachna vigintioctomaculata and Oxycetonia jucunda, were first studied by means of colophony-paraffin embedding serial section technique and strepteavidin-peroxidase immunohistochemical method. The results showed that the brains of these three taxonomically closely related beetles were remarkably different in composition and size. Mushroom bodies and antennal lobes in Oxycetonia jucunda were conspicuous. Calyces and lobes of the mushroom bodies.were much developed. In contrast, calyces of Ambrostoma quadriimpressum and Henosepilachna vigintioctomaculata were extremely undeveloped. However, the postretinal fibres and circumpharyngeal nerves of Ambrostoma quadriimpressum were highly developed. In the three beetles, 5-HT immunoreactivity was present in all neuropils of the brain and the suboesophageal ganglion. The pattern of 5-HT immunoreactivity and the localization of immunoreactive somata which often clustered into groups were similar among these beetles, while the immunoreactivity intensity was distinct, especially in the lamina. The results suggest that the three beetles have given rise to adaptive radiation under the evolutionary pressure because of the long-term different life styles and living environments in which the taxonomic status of Ambrostoma quadriimpressum is relatively low. The similarity of the pattern of 5-HT immunoreactivity and localization of some positive somata among the three beetles raise the possibility that 5-HT seemes to serve similar physiological function in different insects. Furthermore, 5-HT might be involved in modulating the ingestion by regulating muscular activity and visual sensitivity.