海人酸对家兔海马和尾核神经元的作用

EFFECT OF KAINIC ACID ON HIPPOCAMPAL AND CAUDATE NEURONS IN RABBITS

本文比较了成年兔和幼年兔神经元对海人酸的敏感性,并观察了海人酸对家兔海马和尾核神经元的作用。主要结果为:1.成年兔侧脑室内注射不同剂量的海人酸后,海马不同部位的神经元有不同程度的损伤。注射剂量为0.8μg时,CA_(3)和CA_(4)区的大部分锥体细胞有明显的溃变,细胞皱缩,着色深,并有胶质细胞增生;同时尾核神经元也有严重损伤,胶质细胞大量增生。剂量为0.5μg或0.3μg时,CA_(3)和CA_(4)的锥体细胞约有1/2被破坏。剂量增至1μg时,锥体细胞损伤范围扩大,溃变更严重。2.幼兔侧脑室内注射0.1μg或0.2μg海人酸后,海马的锥体细胞有一定的损伤,但仪限于CA_(3)a区。3.向成年兔海马CA_(2)区注射0.3μg海人酸后,海马神经元即有明显的损伤,但只局限于注射的部位。成年兔尾核头部注射0.3μ海人酸后,可在注射部位观察到损伤的神经元和数在的胶质细胞。成年家兔海马锥体细胞对海人酸的敏感性较幼兔为强。海人酸对家兔海马锥体细胞的作用比较强,同时尾核神经元对海人酸也有一定的敏感性。

Kainic acid(KA)is now being widely used in neurobiology as a lesioning tool but,until recently,no neurohistological studies had been done on rabbits.The present study was undertaken to investigate the effect of kainic acid on hippocampal and caudate neurons in adult and young rabbits.Our results were as follows:1.Intraventricular injection of 0.8μg of KA caused destruction of the most of pyramidal cells in CA_(3)and CA_(4)in adult rabbits.At the same time damage to caudate neurons was also observed.After injection of 0.3 of 0.5μg of KA approximately one half of neurons in CA_(3)and CA_(4)was destroyed.Injection of KA with higher dose(1μg)caused more extensive damage to hippocampal neurons.However,after intraventricular injection of KA(0.1 or 0.2μg)in young rabbits(15~18 days old),the damage to some pyramidal ceils was observed only in CA_(3)a.2.Injection of 0.3μg KA into rabbit hippocampus caused destruction of neurons confined to the injected area.Intracaudate injection of KA with same dose(0.3μg)caused a small loss of caudate neurons,and the damage seemed less extensive.It was suggested that given proper care,KA can be also used to lesion selectively most perikarya in rabbit brain area.