Neurocomputing and Neurorobotics Research Group, Complutense University of Madrid, Avda Arcos de Jalon 118, 28037 Madrid, Spain.
Neuroscience. 2010 Aug 25;169(2):893-905. doi: 10.1016/j.neuroscience.2010.04.077. Epub 2010 May 7.
Oscillatory activity at both the single and multiunit levels has been reported in most central nervous system structures, and is postulated as a key factor in information processing and coding. Rats provide an excellent model for oscillation-based information processing, since tactile perception of the environment is achieved by rhythmic movements of their whiskers and information-related rhythmic activity has been identified in the thalamus and cortex. However, rhythmic activity related to information processing has never been reported in the sensory trigeminal complex (STC), the first brain stem relay station for whisker-related tactile information. In the present work, we demonstrate the existence of neural oscillations in the vibrissae-related neurons of the nuclei principalis (Pr5), oralis (Sp5o), interpolaris (Sp5i) and caudalis (Sp5c). Rhythmic activity was associated with the main task of each nucleus, prominent in nuclei responsible for tactile vibrissae information processing (up to 17% oscillating neurons in Pr5 and 26% in Sp5i) and less conspicuous in those concerned with pain (8% oscillating neurons in Sp5o and in Sp5c). The higher percentage of oscillating neurons and higher frequencies in Sp5i than in Pr5 suggests an active role for rhythmic activity in integrating multivibrissa inputs. Oscillations are generated within the brainstem; data obtained from decorticated animals suggest the existence of a differential cortical control of the rhythmic processes in STC nuclei. Corticofugal activity modifies oscillation frequency and synchronization strength of the rhythmic activity mainly during tactile stimulation of the vibrissae.
在大多数中枢神经系统结构中，都有报道称存在单神经元和多神经元水平的振荡活动，并且该活动被认为是信息处理和编码的关键因素。大鼠为基于振荡的信息处理提供了一个极好的模型，因为它们的胡须的有节奏运动实现了对环境的触觉感知，并且已经在丘脑和皮层中识别出与信息相关的节律性活动。然而，与信息处理相关的节律性活动从未在感觉三叉神经复合体（STC）中报道过，STC 是与胡须相关的触觉信息的第一个脑干中继站。在目前的工作中，我们证明了在与触须相关的神经元中存在神经振荡，这些神经元位于主核（Pr5）、口腔核（Sp5o）、中间核（Sp5i）和尾核（Sp5c）中。节律性活动与每个核的主要任务相关联，在负责触觉胡须信息处理的核中表现明显（在 Pr5 中有高达 17%的振荡神经元，在 Sp5i 中有 26%），而在与疼痛相关的核中则不太明显（在 Sp5o 和 Sp5c 中有 8%的振荡神经元）。Sp5i 中振荡神经元的百分比和频率都高于 Pr5，这表明节律性活动在整合多触须输入方面发挥了积极作用。振荡是在脑干内产生的；从去皮质动物获得的数据表明，皮质对 STC 核的节律过程存在差异控制。皮质传出活动主要在触须刺激胡须时改变振荡频率和节律活动的同步强度。
