THE NIGROTHALAMIC PROJECTIONS STUDIED WITH HRP TECHNIQUE IN THE RAT / 解剖学报

ABSTRACT

The nigrothalamic projections were studied with HRP technique in 40 rats.Theanimals were divided into two groups.In one group HRP was injected into varioussubdivisions of the thalamus to observe the retrograde labelled cells in the reticularzone of substantia nigra(SNR)and in the other group HRP was injected into SNRto observe the anterograde labelled fibers and terminals in the thalamus.The nigrothalamic projections were found to originate mainly from SNR,but afew from the compact zone of substantia nigra(SNC)were also observed.Thefibers originated from all parts of the SNR,but the fibers originating from thecaudal part out number those from the rostral part and the ventral part was foundto predominate over the dorsal part.The nigrothalamic projections mainly terminated in ventral medial nucleus ofthe thalamus,but a few fibers terminating in dorsal medial nucleus,parafascicularisnucleus,ventral anterior nucleus and central lateral nucleus of the thalamus were alsofound.It is essentially similar with the site of termination and distribution ofnigrothalamic fibers in the cat and monkey,but there are some quantitative differ-ences.