Effect of serotonin depletion on seizures learning-memory in pilocarpine-induced epileptic rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the relationship between serotonin (5-HT) and epilepsy and the mechanism of learning-memory in pilocarpine (PILO)-induced epileptic rats after 5,7-dihydroxytryptamine (5,7-DHT) microinjection in median raphe nucleus.</p><p><b>METHODS</b>Adult S D rats were randomly divided into 3 groups: PILO group, PILO+ 5,7-DHT group, vehicle control group; PILO group was divided into two groups by status epilepticus (SE): PILO + SE group and PILO - SE group. The rats' seizures and cortex electroencephalography (EEG) were observed by video EEG. The rats' spatial learning-memory was evaluated by Morris water maze. Finally, serotonergic neuron in raphe nuclei was observed by immunohistochemistry.</p><p><b>RESULTS</b>After treatment of 5,7-DHT (PILO + 5,7-DHT group), the success rate, the mortality and the frequency of chronic spontaneous seizures in pilocarpine-induced epilepsy model were all improved. Compared with the control group, the number of serotonergic neuron in raphe nuclei was decrease in PILO + SE group (P < 0.05). Moreover, it's extremely decrease in PILO + 5,7-DHT group (P < 0.01). Compared with control group, the mean escape latency was prolonged, the times of crossing target was decreased and the retention time in target zone was shortened in PILO + SE group (P < 0.05), but there was no significant difference between PILO + SE group and PILO + 5,7-DHT group.</p><p><b>CONCLUSION</b>Depletion of serotonin may facility the rats' epileptic seizures, but we could not interpret which may cause epileptic rats' cognitive deficit.</p>

Analysis of CLCN1 gene mutations in 2 patients with myotonia congenita / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate chloride channel 1 (CLCN1) gene mutation and clinical features of 2 Chinese patients with myotonia congenita.</p><p><b>METHODS</b>Clinical data of a patient from a family affected with myotonia congenita in addition with a sporadic patient from Fujian province were analyzed. Exons of CLCN1 gene were amplified and sequenced.</p><p><b>RESULTS</b>The proband from the affected family was found to carry a c.1024G>A heterozygous missense mutation in exon 8, whilst the sporadic patient has carried a c.1292C>T heterozygous missense mutation in exon 11.</p><p><b>CONCLUSION</b>Detection of CLCN1 gene mutation is an effective method for the diagnosis of myotonia congenita. Exon 8 of CLCN1 gene may be a mutational hotspot in Chinese patients with myotonia congenita.</p>

The effect of high frequency stimulation of epileptic foci on the release of glutamate and gamma-aminobutyric acid in hippocampus of the kainic acid-kindled rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe the dynamics of hippocampal release of glutamate (Glu) and gamma-aminobutyric acid (GABA) in epilepsy (TLE) after administration with high frequency stimulation (HFS).</p><p><b>METHODS</b>The SD were divided into four groups (n =10): (1) Control group (KB) the rats were injected intraperitoneally with saline 0.9%. (2) Kainic acid (KA) group: the rats were injected with KA. (3) Pseudo-deep brain stimulation (DBS) group: the KA-induced rats were implanted with rheophores alone. (4) DBS group: KA induced-rats with DBS in hippocampal epileptic foci. We then collected hippocampal extracellular fluid by microdialysis and the levels of Glu and GABA were measured by high-performance liquid chromatography (HPLC) and fluorescence detection.</p><p><b>RESULTS</b>There was no difference in the baseline of Glu and GABA in the four groups. In contrast, a significant increase in the content of Glu and GABA was shown in the three periods of KA-kindled seizures. Electrical stimulation of hippocampus resulted in a decrease of hippocampal Glu contents, while there was no change in GABA contents. Additionally, HFS of hippocampus normalized the Glu/GABA ratio in the chronic period of seizures.</p><p><b>CONCLUSION</b>The high frequency stimulation of epileptic foci may protect against seizures by modulating the extracellular release of hippocampal Glu.</p>

Evaluation of brain dysfunction in chronic anoxic encephalopathy with evoked potentials / 中国应用生理学杂志

<p><b>AIM</b>To explore the relationship between evoked potentials (EPs) and chronic anoxic brain damage by chronic intermittent hypoxia (CIH), and provide theory evidence for diagnosis and treatment of anoxic encephalopathy.</p><p><b>METHODS</b>BAEP and SLSEP were recorded in rat model with CIH (hypoxia group) and rat with normoxia (normal group). Morris water maze was used to observe learning and memory ability. Immunohistochemical method was used to investigate the expression levels of caspase-3 in brain tissue.</p><p><b>RESULTS</b>The peak latency (PL) of wave I, III, V and the interpeak latency (IPL) of wave III - V, I - V in BAEP in hypoxia group were much longer than that of in normal group (P < 0.05). The PL of wave N1, P1 of SEP in hypoxia group were much longer than that of in normal group (P < 0.05). In the water mase test, the escape latency (EL) of hypoxia group was much longer than normal group (P < 0.01). The number of caspase-3 positive cells in hypoxia group was much larger than that of in normal group (P < 0.05). There was a positive correlation among BAEP, SLSEP, the number of caspase-3 positive neuron and EL of water mase.</p><p><b>CONCLUSION</b>The alteration of BAEP and SLSEP has an apparent correlation with chronic anoxic brain damage. This provides theory evidence for diagnosis and treatment of anoxic encephalopathy.</p>