ACETYLCHOLINESTERASE HISTOCHEMISTRY OF THE THALAMUS IN THE PRIMATE

Objective To observe the distribution of acetylcholinesterase activity in the thalamus of the monkey.Methods Histochemical method was used to detect the acetylcholinesterase activity in the thalamus.Results Acetylcholinesterase was found to be inhomogeneous distribution in the primate thalamus and to reveal previously uncovered inhomogeneity within certain thalamic nuclei and their subdivisions. The medial, ventral and posterior nuclear groups displayed markedly uneven acetylcholinesterase reaction.In the mediodorsal nucleus,three distinct sbudivisions were revealed by acetylcholinesterase histochemistry, medial magnocellular part, ventral sector of central parvicellular part and dorsolateral sector of lateral pars multiformity showed weak, moderate and strong acetylcholinesterase activity, respectively. In the ventral nuclear group, acetylcholinesterase histochemistry was strong in the medial part of ventral posterior nucleus, moderate in the magnocellular part of ventral anterior, caudal, medial, oral and pars postrema parts of ventral lateral nucleus, as well as lateral part of ventral posterior nucleus, poor and weak in the inferior part of ventral posterior nucleus, par compacta of the medial part of ventral posterior nucleus and parvicellular part of ventral anterior nucleus. In the pulvinar nucleus, acetylcholinesterase reaction ranged from weak, moderate to strong in the parts of the oral, medial and lateral, as well as inferior of this nucleus, respectively. Regional variations of acetylcholinesterase activity within the thalamic nuclei and their subdivisions can help to identify them by acetylcholinesterase histochemistry. In addition, the dark patches of strong acetylcholinesterase activity contrasting with a lighter surrounding matrix were revealed within the parvicellular part and pars multiformis of mediodorsal nucleus, paracentral nucleus, central lateral nucleus, pars postrema part of ventral lateral nucleus and medial habenula nucleus, as well as medial part of pulvinar necleus, respectively.Conclusion Acetylcholinesterase histochemistry can serve as useful marker for delineating the thalamic nuclei and their sbudivisions. The different distribution of acetylcholinesterase histochemistry implies the activity of thalamic nuclei may be modulated by cholinergic systems.

Effect of anterior nucleus of thalamus stimulation on glucose metabolism in hippocampus of epileptic rats

Background Electrical stimulation of seizures. In this study, we investigated epileptic rats. the anterior nucleus of the thalamus （ANT） appears to be effective against changes in glucose metabolism during high-frequency stimulation of ANT in Methods Three groups of rats were used： （1） a stimulation group （n=12）, （2） a sham stimulation group （n=12） with seizures induced by stereotactic administration of kainic acid （KA）, and （3） a control group （n=12） with sham surgery. Concentric bipolar electrodes were stereotaxically implanted unilaterally in the ANT. High-frequency stimulation was performed in each group except the sham stimulation group. Microdialysis probes were lowered into the CA3 region of the hippocampus unilaterally but bilaterally in the.stimulation group. The concentrations of glucose, lactate, and pyruvate in dialysate samples were determined by an ISCUS microdialysis analyzer. Results The extracellular concentrations of lactate and lactate/pyruvate ratio （LPR） of epileptic rats were significantly higher than in control rats （P=0.020, P=0.001; respectively）. However, no significant difference in the concentration of glucose and pyruvate was found between these groups （P 〉0.05）. Electrical stimulation of ANT induced decreases in lactate and LPR in the ipsilateral hippocampus （KA injected） of the stimulation group （P 〈0.05）, but it did not influence the glucose metabolism in the contralateral hippocampus （P 〉0.05）. Conclusions This study demonstrated that the glycolysis was inhibited in the ipsilateral hippocampus of epileptic rats during electrical ANT stimulation. These findings may provide useful information for better understanding the mechanism of ANT-deep brain stimulation.

High-frequency stimulation of anterior nucleus thalamus improves impaired cognitive function induced by intra-hippocampal injection of Aβ1-40 in rats

Background The advent of brain stimulation techniques to treat movement disorders and psychiatric diseases has shown potential to decode the neural mechanism that underlies the cognitive process by modulating the interrupted circuit.Here,the present investigation aimed at evaluating the influence of deep brain stimulation of the anterior nucleus thalamus （ANT-DBS） on memory.Methods Thirty-two rats were randomized into phosphate buffer saline （PBS） group （n=8,rats received PBS injections without implantation of electrodes into the ANT）,Alzheimer＇s dementia （AD） group （n=8,rats received Aβ1-40 injections without implantation of electrodes into the ANT）,ANT sham stimulation group （n=8,rats received Aβ1-40 injections with implantation of electrodes into the ANT but without stimulation） and ANT stimulation group （n=8,rats received Aβ1-40 injections with implantation of electrodes into the ANT and stimulation）.A Morris maze test was used for determining the effect of electrical stimulation on cognitive function in rats.The data were assessed statistically with one-way analysis of variance （ANOVA） followed by Tukey＇s tests for multiple post hoc comparisons.Results The data showed that in the training test,PBS group and AD group managed to learn the hidden-platform faster and faster while AD group needed a significantly longer time to reach the platform than PBS group （P ＜0.05）.Meanwhile,ANT stimulation group demonstrated a significantly shorter time to reach the platform （P ＜0.05） compared to the AD group,while there was no significant difference between the ANT sham stimulation group and the AD group （P ＞0.05）.On the probe test,the AD group spent less time （（10.15±2.34） seconds） in the target quadrant than the PBS group （（28.20±2.75） seconds） （P ＜0.05）.And the times of platform-traversing of the AD group （3.35±1.12） significantly decreased compared with the PBS group （8.69±2.87） （P ＜0.05）.However,the times of platform-traversing and the time spent in the target quadrant of the ANT stimulation group significantly increased compared to the AD group （P ＜0.05）,while times of platformtraversing or the time spent in the target quadrant was not significantly different between the ANT sham stimulation group and the AD group （P ＞0.05）.Conclusion Bilateral high-frequency stimulation of the ANT may be useful as a potential therapeutic modality for cognitive dysfunction in AD.

INFLUENCE OF 5-HYDROXYTRYPTAMINE MICRO INJECTED INTO PREOPTIC AREA ON ELECTRO ACTIVITIES OF PAIN RESPONSE NEURONS IN PARAFASCICULAR NUCLEUS OF THALAMUS IN RAT

Many research works through out the world show that the preoptic area(POA) is a region concerned with analgesia. Electric stimulation to this region could enhance markedly pain threshold and exert an analgesic effect. Central 5-hydroxytryptamine (5-HT) plays an important role in pain mediation. Acupuncture could accelerate the synthe-

Properties of oscillatory neuronal activity in the basal ganglia and thalamus in patients with Parkinson’s disease

Background:The cardinal features of Parkinson’s disease(PD)are bradykinesia,rigidity and rest tremor.Abnormal activity in the basal ganglia is predicted to underlie the mechanism of motor symptoms.This study aims to characterize properties of oscillatory activity in the basal ganglia and motor thalamus in patients with PD.Methods:Twenty-nine patients with PD who underwent bilateral or unilateral electrode implantation for subthalamic nucleus(STN)DBS(n=11),unilateral pallidotomy(n=9)and unilateral thalamotomy(n=9)were studied.Microelectrode recordings in the STN,globus pallidus internus(GPi)and ventral oral posterior/ventral intermediate of thalamus(Vop/Vim)were performed.Electromyography of the contralateral limbs was recorded.Single unit characteristics including interspike intervals were analyzed.Spectral and coherence analyses were assessed.Mean spontaneous firing rate(MSFR)of neurons was calculated.Analysis of variance and χ^(2) test were performed.Results:Of 76 STN neurons,39.5% were 4–6 Hz band oscillatory neurons and 28.9% were β frequency band(βFB)oscillatory neurons.The MSFR was 44.2±7.6 Hz.Of 62 GPi neurons,37.1% were 4–6 Hz band oscillatory neurons and 27.4% were βFB neurons.The MSFR was 80.9±9.6 Hz.Of 44 Vop neurons,65.9% were 4–6 Hz band oscillatory neurons and 9%were βFB neurons.The MSFR was 24.4±4.2 Hz.Of 30 Vim oscillatory neurons,70% were 4–6 Hz band oscillatory neurons and 13.3% were β FB neurons.The MSFR was 30.3±3.6 Hz.Further analysis indicated that proportion of βFB oscillatory neurons in STN and GPi was higher than that of similar neurons in the Vop and Vim(P<0.05).Conversely,the proportion of 4–6 Hz band oscillatory neurons and tremor related neurons in the Vim and Vop was higher than that of STN and GPi(P<0.05).The highest MSFR was for GPi oscillatory neurons whereas the lowest MSFR was for Vop oscillatory neurons(P<0.005).Conclusion:The alterations in neuronal activity in basal ganglia play a critical role in generation of parkinsonism.β oscillatory activity is more prominent in basal ganglia than in thalamus suggesting that the activity likely results from dopaminergic depletion.While both basal ganglia and thalamus have tremor activity,the thalamus appears to play a more important role in tremor production,and basal ganglia β oscillatory activity might be the trigger.

磷脂酶A_2(PLA_2)与G蛋白βr亚单位的作用

磷脂酶Ａ_２（ＰＬＡ_２）与Ｇ蛋白β_ｒ亚单位的作用据ＴＩＮＳＩＳ卷２期６４—６５页报道：早在１９８８年Ａｘｅｌｒｏｄ等提出Ｇ蛋白偶联受体能激活ＰＬＡ。，花生四稀酸（ＡＡ）及其代谢产物也可作为第二信使。当时未受重视，但近年来愈益受到重视与实验材料的支持?..

Three-Dimensional Heterogeneity of Cerebellar Interposed Nucleus-Recipient Zones in the Thalamic Nuclei

The cerebellum is conceptualized as a processor of complex movements and is also endowed with roles in cognitive and emotional behaviors.Although the axons of deep cerebellar nuclei are known to project to primary thalamic nuclei,macroscopic investigation of the characteristics of these projections,such as the spatial distribution of recipient zones,is lacking.Here,we studied the output of the cerebellar interposed nucleus(IpN)to the ventrolateral(VL)and centrolateral(CL)thalamic nuclei using electrophysiological recording in vivo and trans-synaptic viral tracing.We found that IpN stimulation induced mono-synaptic evoked potentials(EPs)in the VL but not the CL region.Furthermore,both the EPs induced by the IpN and the innervation of IpN projections displayed substantial heterogeneity across the VL region in three-dimensional space.These findings indicate that the recipient zones of IpN inputs vary between and within thalamic nuclei and may differentially control thalamo-cortical networks.

Deep brain stimulation of the subthalamic nucleus for essential tremor

Essential tremor （ET）, characterized by a postural and/or kinetic tremor and primarily manifested in theupper extremities, head, and other parts of the body, is one of the most common neurological disorders.1 The traditional target for the neurosurgical treatment of ET, the ventral intermedius nucleus （Vim） of the thalamus, has confirmed that chronic deep brain stimulation （DBS1 is an effective, standard, and primary procedure for ET. However, the loss of tremor suppression due to tolerance of chronic Vim stimulation, accompanied by other adverse effects, such as paresthesias, dysarthria, dysequilibrium, hyperhidrosis, and localized pain, has necessitated changes in the stimulation target in some patients.