The cortical projections of the thalamic intralaminar nuclei, as studied in cat and rat with the multiple fluorescent retrograde tracing technique.

Two retrograde fluorescent tracers were injected in two different areas of the cerebral cortex in rats and in cats. In all the experiments many single labeled cells and only some double labeled ones were seen in the thalamic intralaminar nuclei. The present results suggest that the diffusely distributed intralaminar-cortical projections mainly consist of axons of separate cells, and only to a minor extent of axon collaterals of the same cells.