Goksoy Cuneyt, Demirtas Serdar, Ates Kahraman
Department of Biophysics, Gulhane Military Medical Academy, Etlik, Ankara, Turkey.
Brain Res. 2005 Nov 2;1061(1):42-9. doi: 10.1016/j.brainres.2005.08.050. Epub 2005 Oct 14.
Neurophysiological studies aiming to explore how the brain integrates information from different brain regions are increasing in the literature. The aim of the present study is to explore intramodal (binaural, binocular) and intermodal (audio-visual) interactions in the guinea pig brain through the observation of changes in evoked potentials by generalized continuous background activity. Seven chronically prepared animals were used in the study and the recordings were made as they were awake. Epidural electrodes were implanted to the skulls by using stereotaxic methods. Continuous light for retinal or continuous white noise for cochlear receptors were used as continuous conditioning stimuli for generalized stimulation. To evoke auditory or visual potentials, click or flash were used as transient imperative stimuli. The study data suggest that (a) white noise applied to one ear modifies the response to click in the contralateral ear which is a binaural interaction; (b) continuous light applied to one eye modifies the response to flash applied to the contralateral eye which is interpreted as a binocular interaction; (c) regardless of the application side, white noise similarly modified the response to flash applied to the either eye connoting a nonspecific effect of white noise on vision, independent from spatial hearing mechanisms; (d) on the other hand, continuous light, in either eye, did not affect the response to click applied to any ear, reminding a 'one-way' interaction that continuous aural stimulation affects visual response.
旨在探究大脑如何整合来自不同脑区信息的神经生理学研究在文献中日益增多。本研究的目的是通过观察广义连续背景活动诱发的电位变化，来探究豚鼠大脑中的模态内（双耳、双眼）和模态间（视听）相互作用。本研究使用了7只长期准备好的动物，并在它们清醒时进行记录。通过立体定位方法将硬膜外电极植入颅骨。视网膜的连续光或耳蜗感受器的连续白噪声被用作广义刺激的连续条件刺激。为了诱发听觉或视觉电位，使用短声或闪光作为瞬态指令刺激。研究数据表明：（a）施加于一只耳朵的白噪声会改变对侧耳朵对短声的反应，这是一种双耳相互作用；（b）施加于一只眼睛的连续光会改变对侧眼睛对闪光的反应，这被解释为一种双眼相互作用；（c）无论施加侧如何，白噪声同样会改变施加于任一只眼睛的闪光的反应，这意味着白噪声对视觉有非特异性影响，独立于空间听觉机制；（d）另一方面，任一眼睛中的连续光都不会影响施加于任何耳朵的短声的反应，这提示了一种“单向”相互作用，即连续听觉刺激会影响视觉反应。
