Morin C, Molotchnikoff S
Département de Sciences Biologiques, Université de Montréal, Québec, Canada.
Eur J Neurosci. 1994 Jul 1;6(7):1063-71. doi: 10.1111/j.1460-9568.1994.tb00603.x.
The goal of this study was to examine the role of horizontal connections in rabbit striate neurons. Anaesthetized rabbits were prepared in the usual fashion for single-cell recordings in area 17 of the visual cortex. We compared responses evoked by moving and stationary stimuli prior to, during and after recovery from lateral microinjection of either lidocaine (n = 61), gamma-aminobutyric acid (GABA, n = 18) or bicuculline (n = 8) 2 mm from the recording site. This procedure allows evaluation of the contribution of neighbouring neurons in visual responses. Results showed that striate neurons are dependent on the adjacent cells' excitability. Modification of responses to stationary targets suggests that lateral interactions play a role in the generation of discharges to fixed stimuli. Lateral inactivation preferentially influenced non-directional over direction-selective units. This influence usually resulted in the non-directional neuron becoming directional by attenuation of the visually driven response in one direction. Simple and complex cells tended to be influenced differently by lateral inactivation. Simple cells became less responsive, whereas complex cells became more responsive. This dichotomy among cellular types suggests that simple cells receive mainly excitatory horizontal influences, while complex cells are contacted mostly by lateral inhibitory inputs.
本研究的目的是探讨水平连接在兔视皮层神经元中的作用。以常规方式对麻醉后的兔子进行准备，以便在视觉皮层17区进行单细胞记录。我们比较了在距记录部位2毫米处侧向微量注射利多卡因（n = 61）、γ-氨基丁酸（GABA，n = 18）或荷包牡丹碱（n = 8）之前、期间和恢复后，移动和静止刺激所诱发的反应。该程序可评估相邻神经元在视觉反应中的作用。结果表明，视皮层神经元依赖于相邻细胞的兴奋性。对静止目标反应的改变表明，侧向相互作用在对固定刺激的放电产生中起作用。侧向失活对非方向选择性单位的影响比对方向选择性单位的影响更大。这种影响通常导致非方向选择性神经元通过减弱一个方向上的视觉驱动反应而变成方向选择性神经元。简单细胞和复杂细胞受侧向失活的影响往往不同。简单细胞的反应性降低，而复杂细胞的反应性增加。细胞类型之间的这种二分法表明，简单细胞主要接受兴奋性水平影响，而复杂细胞主要受到侧向抑制性输入的影响。
