大鼠下丘脑室旁核大细胞自发电活动及对去甲肾上腺素反应的增龄性变化

应用神经垂体逆向电刺激，于下丘脑室旁核内用玻璃微电极细胞外记录的方法寻找室旁核神经内分泌大细胞，并观察了３ 月龄、１２ 月龄及２６ 月龄三组大鼠室旁核大细胞的自发放电及对脑室注射去甲肾上腺素（Ｎｏｒｅｐｉｎｅｐｈｒｉｎｅ ，ＮＥ）反应的增龄性变化。结果发现，不同月龄组室旁核大细胞中呈慢不规则、快连续及位相型放电的神经元的比例相似；随增龄室旁核大细胞的自发放电频率增加；室旁核中加压素与催产素神经元对脑室注射ＮＥ的反应发生增龄性变化。这些结果提示：下丘脑室旁核大细胞电生理特性发生增龄性变化，并可能因此导致其分泌功能的变化

AGING CHANGES OF SPONTANEOUS ELECTRICAL ACTIVITIES AND RESPONSES TO NOREPINEPHRINE OF MAGNOCELLULAR PARAVENTRICULAR NUCLEUS NEURONS IN RAT HYPOTHALAMUS

By antidromic stimulation of neurohypophyseal and microelectrode extracellular recording of action potentials(APs), the magnocellular neurons in paraventricular nucleus (PVN) of hypothalamus in 3,12 ,and 26 months rats were identified , then the spontaneous discharge of these neurons and their responses to intracerebralventricle injected norepinephrine were observed.The results showed that the percentages of neurons displaying slow irregular, fast continuous and physic firing patterns of discharge were similar in different age groups,but the firing frequencies of all three firing patterns in aged group were significantly elevated.In addition ,the responses of oxytocin and vasopressin secreting neurons in PVN to intracerebralventricle injected norepinephrine in different age groups were changed.These findings suggest that the spontaneous discharge characterisitics of magnocellular paraventricular neurons and their responses to norepinephrine changed with aging ,and this may give rise to changes of neurosecreting function of these neurons.