电刺激蝙蝠小脑对下丘神经元听反应的影响

THE INFLUENCES OF ELECTRICAL STIMULATION TO CEREBELLUM ON THE ACOUSTICALLY EVOKED RESPONSES OF INFERIOR COLLICULAR NEURONS ES BAT

实验在34只长翼蝠(Miniopterus schrebersi)上进行.使用玻璃微电极在中脑下丘中央核记录听神经元电反应.电刺激点分别位于小脑蚓部、半球和绒球小结叶共观察了515个对超声刺激产生反应的下丘听神经元.当电刺激小脑时,有171个(占33.2%)神经元听反应受到影响.其中126个(占24.5%)表现为抑制,45个(8.7%)表现为易化.抑制效应表现为神经元所反应放电频数降低和反应潜伏期延长.易化效应则相反.抑制与易化潜伏期一般都在6毫秒以上.抑制效应与电刺激强度、声刺激强度以及声刺激和电刺激的时间间隔有关.抑制和易化性影响都是双侧性的.

The influence of electrical stimulation to the cerebellum on acoustically evoked responses of inferior collicular (IC) neurons of 34 FM bats, Miniopterus schrebersi, was studied with conventional auditory physiological techniques. Among 515 1C neurons isolated, responses of 171 (33.30%) IC neurons were affected by cerebellar stimulation. Responses of 126 (24.46%) IC neurons were inhibited an 45 (8.74%) were facilitated. The degree of inhibition was dependent upon the amplitude of both acoustic and electrical stimuli. Inhibition of IC neuron's activity was also dependent upon the time interval between the two stimuli. Both best inhibitory and facilitatory latencies ranged between 6.0 to 37.0 msec, they varied not only among individual IC neurons, but also with the stimulating portion of the cerebellum. Responses of both contralateral and ispilateral IC neurons were affected. Our findings suggest that different portion of cerebellum affects the activity of IC neurons through different multi-synaptic pathways.