Purchase this article with an account.
Z. Markus, A. Rokszin, A. Berényi, Z. Paróczy, G. Braunitzer, G. Benedek, A. Nagy; Spatial Visual Information Processing and Coding in the Caudate Nucleus. Invest. Ophthalmol. Vis. Sci. 2009;50(13):1433.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Despite extensive analysis of the motor functions of the caudate nucleus (CN), little is known about its role in the visual feedback of motor actions. In the present study, we set out to analyze the spatial visual information processing in the CN.
Extracellular single-unit recordings were performed in the CN of halothane-anesthetized, immobilized, artificially ventilated cats.
The visually responsive neurons were located in the dorsolateral part of the caudate body. Most of the units responded optimally to spot-like stimuli moving at a velocity of >20 deg/s. The neurons were also sensitive to drifting gratings and the temporal frequency of the grating modulated the neuronal responses. The CN units responded maximally to gratings of low spatial and high temporal frequencies. They exhibited low spatial and high temporal resolution and fine spatial and temporal frequency tuning. The visual receptive fields of the CN neurons proved to be large. No signs of retinotopy were observed. The CN neurons exhibited significantly different responses to visual stimuli appearing in different regions of their huge receptive field. These neurons have the ability to provide information via their discharge rate at the site of the stimulus, and thus they may serve as panoramic localizers. Furthermore, the sites of maximal responsiveness of the visual CN neurons are distributed over the whole extent of the receptive fields. Our findings support the idea that there is a distributed population code of visual information in the feline CN.
The visual properties of the CN neurons detailed above are similar to those of certain feline extrageniculate visual structures, i.e. the superior colliculus, the suprageniculate nucleus and the anterior ectosylvian cortex. However, these features are strongly different from those of the primary visual cortex and the lateral geniculate nucleus. Accordingly, our results suggest a functional relationship of the CN to the extrageniculate tecto-thalamo-cortical system. This system of the mammalian brain can be involved in motion detection, facilitating the detection of changes during the self-movement of the animal.
This PDF is available to Subscribers Only