Study of the effects of alpha2 adrenoceptor on the development of epileptogenesis in immature rats

抑制性和兴奋性神经递质的失衡在人类和动物癫痫发作模型的发生发展中起着重要作用。据报道，中枢去甲肾上腺素能系统可以抑制点燃的发展。然而，去甲肾上腺素能系统在出生后阶段与成年期相比是不成熟的。因此，为了阐明α-2肾上腺素受体在幼年期癫痫发生发展中的作用，我们观察了不同年龄大鼠(出生后14天、21天、28天和70天)杏仁核点燃发展的影响。α-2激动剂可乐定抑制了28日龄幼鼠和成年大鼠点燃的发展。然而，可乐定促进了14日龄幼鼠点燃行为的发展。联合应用可乐定和α-2拮抗剂育亨宾、咪唑克生或鲁沃西新可阻断可乐定对14日龄幼鼠点燃的促进作用。去甲肾上腺素前体多巴不影响14日龄或21日龄大鼠点燃行为的发生。组氨酸前体1-组氨酸对成年和14、21日龄幼鼠的点燃发育均有抑制作用。目前的药理学研究表明，α-2肾上腺素受体对杏仁核点燃发育的影响具有年龄特异性。

The imbalance in inhibitory and excitatory neurotransmitters plays an important role in the development of epileptic seizures in human and animal models. Central noradrenergic systems are reported to suppress the development of kindling. However, noradrenergic systems are immature in postnatal period compared with in adult period. Therefore, to elucidate the effect of alpha-2 adrenoceptor on the development of epileptogenesis in immature period, we investigated the effects on the development of amygdaloid kindling in various aged rats (postnatal 14 days, 21 days, 28 days, and 70 days).1. Alpha-2 agonist, clonidine, suppressed the development of kindling in 28-day-old young rats as well as in adult rats. However, the development of kindling was facilitated by clonidine in 14-day-old pup rats.2. Facilitative effect of development of kindling by clonidine in 14-day-old pup rats was blocked with combined administration of clonidine and alpha-2 antagonist such as yohimbine, idazoxan or rauwolscine.3. Noradrenaline precursor droxydopa did not affect the development of kindling in 14-or 21-day-old rats.4. Histamne precursor 1-histidine caused inhibitory effects on the development of kindling in both adult and 14-, 21-day-old pup rats.The present pharmacological studies indicate that the effects of alpha-2 adrenoceptors on the development of amygdaloid kindling are age specific.