Hughes Cathryn R, Keele N Bradley
Department of Psychology and Neuroscience, Baylor University, One Bear Place, Waco, TX 76798-7334, USA.
Epilepsy Behav. 2006 Dec;9(4):557-63. doi: 10.1016/j.yebeh.2006.09.002. Epub 2006 Oct 12.
Temporal lobe epilepsy may be associated with emotional difficulties such as depression and anxiety. Because the amygdala is involved in both epilepsy and emotion, common neural mechanisms in this temporal lobe structure may underlie the emotional disturbances observed in people with epilepsy. The neurotransmitter serotonin (5-hydroxytryptamine, or 5-HT) is implicated in many psychopathologies, and 5-HT also modulates amygdala excitability. Therefore, the present study uses the fear-potentiated startle (FPS) paradigm to investigate the effect of neuronal excitability on fear behavior in rats treated with p-chlorophenylalanine (PCPA) to chronically inhibit 5-HT synthesis. PCPA treatment selectively enhanced FPS in individually housed rats. The exaggerated FPS response was reduced to control level by the anticonvulsant phenytoin at 10mg/kg, and phenytoin at 30mg/kg further decreased FPS behavior. These data suggest that a subseizure state of neuronal excitability mediated by low 5-HT in brain fear circuits may be associated with pathological fear behavior.
颞叶癫痫可能与抑郁和焦虑等情绪问题有关。由于杏仁核参与癫痫和情绪活动，颞叶结构中的共同神经机制可能是癫痫患者所观察到的情绪障碍的基础。神经递质血清素（5-羟色胺，或5-HT）与许多精神病理学有关，并且5-HT还调节杏仁核的兴奋性。因此，本研究使用恐惧增强惊吓（FPS）范式来研究神经元兴奋性对用对氯苯丙氨酸（PCPA）处理以长期抑制5-HT合成的大鼠恐惧行为的影响。PCPA处理选择性地增强了单独饲养大鼠的FPS。抗惊厥药苯妥英钠以10mg/kg可将过度的FPS反应降低至对照水平，而30mg/kg的苯妥英钠进一步降低了FPS行为。这些数据表明，大脑恐惧回路中由低5-HT介导的神经元兴奋性亚惊厥状态可能与病理性恐惧行为有关。
