Neurochemical identification of cholinergic forebrain projection sites of the nucleus tegmentalis dorsalis lateralis.

The projection sites of the nucleus tegmentalis dorsalis lateralis (ntdl) were examined in rats by a biochemical technique. The ntdl was destroyed unilaterally and brains were assayed after 14 days survival for changes in choline acetyltransferase activity in discrete brain areas. A bilateral projection appears to exist to the anteroventral and the posterior nucleus of the thalamus. An ipsilateral projection to the lateral portion of the medial thalamic nucleus and the ventral geniculate was found. It is suggested that the nucleus tegmentalis dorsalis lateralis may play a role in the modulation forebrain areas.