de Gortari P, Joseph-Bravo P, Monroy-Ruiz J, Martínez A, Cisneros M, Fernández Guardiola A
Instituto de Biotecnología of Universidad Nacional Autónoma de México, Mexico.
Epilepsia. 1998 Aug;39(8):897-903. doi: 10.1111/j.1528-1157.1998.tb01188.x.
Thyrotropin-releasing hormone (TRH), present in extra hypothalamic brain areas, has been proposed to have neuromodulatory functions and to be susceptible to change by electrical stimulation paradigms. We measured TRH concentrations of several brain areas during kindling development before its establishment and determined whether the changes detected in TRH levels were related to the behavioral stages of kindling, the number of stimulations required to reach these stages and, with the electrophysiological parameters characteristic of this paradigm (amygdaloid afterdischarge (AD) frequency, duration, and propagation).
Male Wistar rats were implanted stereotaxically with indwelling bipolar electrodes in the basolateral nucleus of the amygdala and with two stainless-steel electrodes epidurally in frontal cortex. Amygdaloid kindling was induced by daily electrical stimulation; AD frequency and duration were recorded and analyzed throughout the development of kindling. TRH was extracted from several regions and quantified by radioimmunoassay (RIA).
Modifications in TRH concentrations were detected, depending on the region assayed, from stage II of kindling. A positive correlation was noted between the levels of TRH and the frequency and propagation of AD, but not with the number of stimulations. The rate of change in TRH concentration in relation to AD frequency or duration was highest in frontal cortex followed by hippocampus and amygdala.
A graded response was noted in the increase in TRH concentration dependent on the increase of AD frequency and propagation. The rate of response correlated with the region's epileptogenic susceptibility.
促甲状腺激素释放激素（TRH）存在于下丘脑外的脑区，有人提出它具有神经调节功能，并且易受电刺激模式的影响而发生变化。我们在点燃发展确立之前测量了几个脑区的TRH浓度，并确定在TRH水平检测到的变化是否与点燃的行为阶段、达到这些阶段所需的刺激次数以及该模式的电生理参数（杏仁核后放电（AD）频率、持续时间和传播）有关。
将雄性Wistar大鼠立体定向植入杏仁核基底外侧核的留置双极电极以及额叶皮质硬膜外的两个不锈钢电极。通过每日电刺激诱导杏仁核点燃；在点燃发展过程中记录并分析AD频率和持续时间。从几个区域提取TRH，并通过放射免疫测定（RIA）进行定量。
从点燃的II期开始，根据检测区域的不同，检测到TRH浓度发生了变化。TRH水平与AD的频率和传播之间存在正相关，但与刺激次数无关。额叶皮质中TRH浓度相对于AD频率或持续时间的变化率最高，其次是海马体和杏仁核。
观察到TRH浓度的增加存在分级反应，这取决于AD频率和传播的增加。反应速率与该区域的致痫易感性相关。
