Characteristics of electrographic and behavioral seizures induced by chronic tetanization of the right caudate-putamen in rats / 中国应用生理学杂志

<p><b>AIM</b>The electrographic and behavioral kindling effects were induced by chronic tetanization of the right caudate-putamen (CPu) to study the target-behavior expression involved in the CPu or hippocampus (HPC) network abnormalities.</p><p><b>METHODS</b>Experiments were performed on 58 SD rats. Tetanization (60Hz,0.4 - 0.6mA, 2s) was delivered into the CPu or the HPC, once a day, for 7-12 days. Animal behaviors were observed every day and depth electrographs were recorded at the beginning or at the end of the experiments.</p><p><b>RESULTS</b>Chronic tetanization of the CPu or of the HPC induced: (1) Rhythmic sharp waves in the CPu and paroxysmal epileptiform events in the HPC electrographs. (2) Primary behavioral seizures, secondary behavioral seizures, and kindling effects, including wet dog shakes (WEDS), rearing, face washing, immobility, chewing and head nodding. (3) Lower rate of primary WEDS (P < 0.01), and higher rate of secondary WEDS (P < 0.01) in the CPu-tetanized rats. (4) Longer silent period of behavioral seizures before kindling appeared in the CPu-tetanized rats.</p><p><b>CONCLUSION</b>Kindling effects in the CPu-tetanized rats resembles those in the HPC-tetanized rats. The CPu might participate in the origin of epileptic focus and be involved in reestablishment of limbic epileptic networks, which may be responsible for the target-behavioral seizures.</p>

Network interactions between caudate putamen and hippocampus contralateral to the right tetanized corpus callosum in rats / 中国应用生理学杂志

<p><b>AIM</b>To study the role of epileptic neural networks reestablished in contralateral caudate putamen (CPu)-hippocampus(HPC) by using chronic tetanization of the right corpus callosum (CTRCC).</p><p><b>METHODS</b>Experiments were performed on 50 SD rats under anaesthesia. The left CPu (LCPu) and the left HPC(LHPC) electrographs were synchronously recorded after acute tetanization following CTRCC (60 Hz, 0.4-0.6 mA, 2 s).</p><p><b>RESULTS</b>(1) In contralateralization to the side implanted interconvertible network inhibition between the CPu and the HPC were induced by combinedly using chronic and acute tetanization of the RCC. (2) Electrographic kindling in the LCPu or in the LHPC was recorded after CTRCC. (3) In case the LCPu or the LHPC electrographs were not kindled after CTRCC, hypsarrhythmia in the LCPu and reduced sharp waves in the HPC were induced b y repetitive tetanization of the RCC once again. Primary afterdischarges in the LCPu or in the LHPC electrographs were evoked by combinedly using chronic and acute tetanization of the RCC.</p><p><b>CONCLUSION</b>Pathophysiological neural networks in the CPu and in the HPC might be reestablished in another side of hemispheres by chronic over-activation of the right CC, which is related to epileptogenesis. Abnormal interactions between the two functional neural networks might be involved in formation of secondary epileptic focus.</p>

Effects of tetanization of the right caudate-putamen on the depth electrographs in the hippocampus or medial temporal lobe neocortex electrographs in rats / 中国应用生理学杂志

<p><b>AIM</b>To study the role of the caudate-putamen (CPu)-hippocampus (HPC)-medial temporal lobe neocortex (MTNC) neural pathway in re-establishment of pathophysiological neural networks related to epileptogenesis.</p><p><b>METHODS</b>Experiments were performed under anaesthesia on 45 SD rats. The right HPC, the right MTNC, bilateral HPC, the right HPC and the right MTNC depth electrographs were recorded with bipolar concentric electrodes. Tetanization (60 Hz, 2 s, 0.4 - 0.6 mA) of the right CPu or of the right HPC trains were used to establish acute rat epilepsy model. These depth electrographs were detected before or after tetani were delivered about 10 times at 10 min intervals.</p><p><b>RESULTS</b>Tetanization of the right CPu induced (1) primary afterdischarges and unilateral or bilateral HPC electrographic afterdischarges and kindling effect or inhibition-rebound-kindling effect were induced by repetitive tetani into the right CPu. (2) After injection of scopolamine (0.05 mg/kg i.p.), 3 Hz slow oscillations in HPC electrographs exhibited long-term potentiation followed by repetitive tetani into the right CPu. (3) After administration of scopolamine (i.p.) electrographic oscillations at 3Hz with synaptic modification in bilateral HPC were induced and epileptiform activities in the RHPC were synchronized with those in the RMTNC.</p><p><b>CONCLUSION</b>Pathophysiological neural networks from the Cpu into the HPC might be reestablished by overactivation of the right CPu, in which two hemispheres are involved while temporal lobe epileptogenesis was facilitated.</p>