Faculty of Pharmacy, Department of Pharmacology, Suleyman Demirel University, Isparta, Turkey.
Faculty of Medicine, Department of Pharmacology, Hacettepe University, Ankara, Turkey.
Synapse. 2020 Sep;74(9):e22155. doi: 10.1002/syn.22155. Epub 2020 Apr 3.
Epileptogenesis is a dynamical process that involves synaptic plasticity changes such as synaptic reorganization of excitatory and inhibitory systems and axonal sprouting in the hippocampus, which is one of the most studied epileptogenic regions in the brain. However, the early events that trigger these changes are not understood well. We investigated short-term and long-term synaptic plasticity parameters and T-type Ca channel activity changes in the early phase of a rat kindling model. Chronic pentylenetetrazole (PTZ) application was used in order to induce the kindling process in rats. The recordings were obtained from hippocampal slices in the CA1 region at 25th day of PTZ application. Tetraethylammonium was used in order to induce long-term potentiation and T-type Ca channel activity was assessed in the presence of mibefradil. We found that tetraethylammonium-induced long-term potentiation was not prevented by mibefradil in the kindling group in contrast to control group. We also found an increase in paired-pulse ratios in the PTZ-applied group. Our findings indicate an increase in the "T-type Ca channel component of LTP" in the kindling group, which may be an early mechanism in epileptogenesis.
癫痫发生是一个动态过程，涉及到突触可塑性变化，如兴奋性和抑制性系统的突触重组和海马中的轴突发芽，海马是大脑中研究最多的致癫痫区域之一。然而，触发这些变化的早期事件还没有被很好地理解。我们研究了大鼠点燃模型早期的短期和长期突触可塑性参数和 T 型钙通道活性变化。慢性戊四氮（PTZ）应用于诱导大鼠的点燃过程。在 PTZ 应用的第 25 天，从海马 CA1 区的脑片上进行记录。四乙基铵用于诱导长期增强，并用米贝地尔评估 T 型钙通道活性。我们发现，与对照组相比，米贝地尔并没有阻止点燃组中四乙基铵诱导的长期增强。我们还发现 PTZ 处理组的成对脉冲比增加。我们的研究结果表明，点燃组中“LTP 的 T 型钙通道成分”增加，这可能是癫痫发生的早期机制。
