Rodman H R, Gross C G, Albright T D
Department of Psychology, Princeton University, New Jersey 08544.
J Neurosci. 1989 Jun;9(6):2033-50. doi: 10.1523/JNEUROSCI.09-06-02033.1989.
The middle temporal area (MT) of the macaque monkey is a region of extrastriate cortex involved in the analysis of visual motion. MT receives strong projections from striate cortex and from area V2, which is dependent on striate for visual responsiveness. Accordingly, the visual properties of MT neurons have been thought to reflect the further processing of its input from striate cortex. We examined the dependence of MT activity on pathways deriving from striate cortex by recording from MT neurons following removal of their striate input. Repeated recordings in area MT were made in 4 hemispheres of anesthetized macaques following either partial or total ablations of striate cortex. Cells in MT were tested for responsiveness, selectivity for direction of motion and direction tuning, and ocular dominance. Receptive fields were also plotted. In an additional animal, we recorded from MT neurons during reversible cooling of the central representation in striate cortex. We found that striate cortex removal or inactivation did not abolish the visual responsiveness of the majority of MT cells. Although the residual responses were generally much weaker than in the intact animal, direction selectivity and binocularity were still present. Moreover, receptive field size and overall topography appeared unaltered.
猕猴的颞中区（MT）是纹外皮层的一个区域，参与视觉运动分析。MT接受来自纹状皮层和V2区的强烈投射，V2区的视觉反应依赖于纹状皮层。因此，MT神经元的视觉特性被认为反映了其来自纹状皮层输入的进一步处理。我们通过在去除MT神经元的纹状输入后记录MT神经元的活动，研究了MT活动对源自纹状皮层的通路的依赖性。在麻醉猕猴的4个半球中，在纹状皮层部分或全部切除后，对MT区进行重复记录。测试MT区的细胞的反应性、对运动方向的选择性和方向调谐以及眼优势。还绘制了感受野。在另一只动物中，我们在纹状皮层中央表征的可逆冷却过程中记录MT神经元的活动。我们发现，去除或失活纹状皮层并没有消除大多数MT细胞的视觉反应性。虽然残余反应通常比完整动物中的反应弱得多，但方向选择性和双眼性仍然存在。此外，感受野大小和整体地形图似乎未改变。
