Laminar origin of cortical neurons which project upon the caudate nucleus: A horseradish peroxidase investigation in the cat

Abstract

The horseradish peroxidase method was used to study the cortical projections upon the caudate nucleus in the cat. The cells of origin of the corticostriatal projection arise from both the supragranular (II and III) and infragranular (V and VI) cortical layers, in contrast to all other known corticofugal pathways to subcortical structures, which appear to arise only from the infragranular layers. This finding has been verified in the present study by several novel surgical procedures, which include direct injections into the caudate nucleus, after the overlying tissues have been removed. The present study also shows that there is a truly widespread distribution of the cells contributing to the corticostriatal projection. Some portion of every neocortical gyrus contains labeled cells, though their relative numbers vary greatly. Also, simple topographical relationships are maintained, but there is much overlap. In addition, present findings show that the corticostriatal projection is strikingly bilateral and originates from regions which are homotopic to the ipsilateral projection.

Effects of excitatory amino acids and their antagonists on membrane and action potentials of cat caudate neurones.

“…Other workers have applied NMA to different mammalian (central neurones during intracellular recordings: In mouse spinal neurones grown in dissociated cultures excitatory amino acids produced depolarizations some of which looked similar to the type 2 effects described here (MacDonald & Wojtowicz, 1980, 1982.…”

“…In earlier reports using extracellular recording techniques PDA was termed a broad spectrum antagonist of excitatory amino acids because it was shown to inhibit excitations elicited by NMDA, quisqualate and kainate in the spinal cord (Davies et al 1981) and those of asp, glu, kainate, NMDA and quisqualate but not ACh on neurones of the caudal trigeminal nucleus (Salt & Hill, 1981, 1982. In the present study, PDA predominantly antagonized NMA, sometimes asp and never glu.…”

“…drug injections and monitoring of the blood pressure, respectively. The skull was exposed and the frontal sinuses were opened bilaterally to allow insertion of two pairs of stainless-steel stimulation electrodes into the precruciate cortex where the 208 EXCITATOR Y AMINO ACIDS IN THE CA UDATE cell bodies of the neurones projecting to the head of the caudate nucleus are located in the cat (Oka, 1980;Royce, 1982;Webster, 1965).…”

Facilitation of Saccadic Eye Movements by Postsaccadic Electrical Stimulation in the Primate Caudate

“…It is noteworthy in this respect that the preferred direction of single caudate projection neurons could change flexibly depending on the direction of expected reward (Kawagoe et al, 1998;Ding and Hikosaka, 2006). Such flexible modulation may be supported by the bilateral corticostriatal connections (Carpenter, 1981;Royce, 1982). Either natural reward or caudate stimulation may be capable of guiding caudate projection neurons to be tuned to whichever direction or position that is associated with reward or stimulation.…”

Latency associated promoter transgene expression in the central nervous system after stereotaxic delivery of replication-defective HSV-1-based vectors

“…Positive staining in the prefrontal cortex was both ipsilateral and contralateral, mainly in layers 5 and 6, which is consistent with previous tracing studies documenting connections of neurones from these layers into the striatum. 51 Other positive areas included the thalamus (paracentral thalamic nucleus, central medial thalamic nucleus and the sub-medial thalamic nucleus) and the substantia nigra both pars compacta and pars reticulata. The number of ␤-gal-expressing cells was established by counting every stained section throughout the brain.…”