Differences of horizontal collateralizations in commissure and association neurons

细胞内记录2/3层锥体神经元对声刺激的反应。在耳穴麻醉下，在单耳和/或双耳条件下，对猫的外耳道施加纯音、滴答声、白噪声和一定带宽的噪声。在许多神经元中，在记录后注入生物细胞素以追踪记录的神经元的轴突的轨迹。以最佳或接近最佳的频率诱导兴奋性突触后电位(EPSPS)。常与动作电位相关的EPSP伴随着膜电位的超极化偏转(IPSP)，这在第3层神经元中比第2层神经元更为明显。在一些神经元中，如果声强增加，IPSP偏转增加，动作电位数目减少，表现出非单调反应特性。在一些深层3层神经元中，以最佳或接近最佳频率或有噪声的双耳刺激比单耳刺激双耳诱发的棘波更少，从而揭示了EI反应的特性。为了比较有IPSP和不有IPSP的神经元的轴突轨迹，我们重建了一些记录到的神经元，然后注入了生物细胞素。这些结果和一些相关的数据已经以摘要的形式和/或全文发表。

Responses of layer 2/3 pyramidal neurons to sound stimuli were recorded intracellularly. Under a light Nembutal anaesthesia, pure tones, clicks, white noises, and noises with a defined band width were applied to cats' external meatus under monaural and/or binaural conditions. In many neurons, biocytin was injected after the recording to trace the courses of axons of the recorted neurons.Excitatory postsynaptic potentials (EPSPs) were induced with best or nearbest frequencies. EPSPs, often associated with action potentials, were followed by hyperpolarizing deflection of the membrane potential (IPSP), which was more conspicous in layer 3 neurons than in layer 2 neurons. In some neurons, if sound intensity was increased, IPSP deflection was increased together with the decreased number of action potentials, revealing the non-monotonic response properties. In some deep layer 3 neurons, binaural stimulation with the best or near-best frequencies or with noise induced less spikes than monaural stimulation of either ear, revealing the EI response properties. Then stronger IPSPs were associated with the binaural stimulation than monaural stimulaiton, and seem to reduce the number of binaurally-induced spikes.In order to compare axonal trajectories of the neurons with IPSP and without IPSP, some of the recorded and then biocytin-injected neurons have been reconstructed.These results and some related data have been published in abstract forms and/or in full papers.