Parsons Matthew M, Krapp Holger G, Laughlin Simon B
Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK.
J Exp Biol. 2006 Nov;209(Pt 22):4464-74. doi: 10.1242/jeb.02560.
In the blowfly Calliphora vicina, lobula plate tangential cells (LPTCs) estimate self-motion by integrating local motion information from the compound eyes. Each LPTC is sensitive to a particular (preferred) rotation of the fly's head. The fly can also sense rotation using its three ocelli (simple eyes), by comparing the light intensities measured at each ocellus. We report that an individually identified tangential cell, V1, responds in an apparently rotation-specific manner to stimulation of the ocelli. This effect was seen with or without additional stimulation of the compound eye. We delivered stimuli to the ocelli which mimicked rotation of the fly's head close to that of the preferred axis of rotation of V1. Alternating between preferred and anti-preferred rotation elicited a strongly phasic response, the amplitude of which increased with the rate of change of light intensity at the ocelli. With combined stimulation of one compound eye and the ocelli, V1 displayed a robust response to ocellar stimuli over its entire response range. These findings provide the opportunity to study quantitatively the interactions of two different visual mechanisms which both encode the same variable--the animal's rotation in space.
在红头丽蝇（Calliphora vicina）中，小叶板切向细胞（LPTCs）通过整合来自复眼的局部运动信息来估计自身运动。每个LPTC对苍蝇头部的特定（偏好）旋转敏感。苍蝇还可以通过比较每个单眼中测量的光强度，利用其三只单眼（小眼）感知旋转。我们报告称，一个单独识别的切向细胞V1，对单眼刺激以一种明显的旋转特异性方式做出反应。无论复眼是否受到额外刺激，这种效应都能观察到。我们向单眼施加模拟苍蝇头部接近V1偏好旋转轴旋转的刺激。在偏好旋转和反偏好旋转之间交替会引发强烈的相位反应，其幅度随着单眼中光强度的变化率增加。当一只复眼和单眼同时受到刺激时，V1在其整个反应范围内对单眼刺激表现出强烈反应。这些发现为定量研究两种不同视觉机制的相互作用提供了机会，这两种机制都编码相同的变量——动物在空间中的旋转。
