Double retrograde tracer study of the thalamostriatal projections to the cat caudate nucleus

The distribution of thalamostriatal neurons projecting to the cat caudate n ucleus was examined by retrograde fluorescent tracers. Thus, Fast Blue and Diamidino Yellow were concomitantly injected in different rostrocaudal, dor soventral, or mediolateral sectors of the caudate nucleus. The main finding s of this study are as follows: (1) few double-labeled cells were found aft er two injections in different sectors of the caudate nucleus; (2) double-l abeled neurons were more abundant after adjacent injections and they were m ainly located in the caudal intralaminar nuclei, in the rhomboid nucleus an d in the dorsal mediodorsal nucleus; and (3) there were variations in the s patial organization of the thalamostriatal neurons projecting to various se ctors of the caudate nucleus in the different thalamic nuclei known to proj ect to this part of the striatum. Synapse 32:80-92, 1999. (C) 1999 Wiley-Li ss, Inc.