Afferent and efferent enkephalinergic systems of the tegmental nuclei of Gudden in the rat: an immunocytochemical study.
We studied the afferent source of L-enkephalin-like immunoreactive (L-ENKLI) fibers in the ventral tegmental nucleus (VT) of Gudden, and efferent and afferent connections of L-ENKLI structures in the dorsal part of the dorsal tegmental nucleus (DDT) of Gudden in the rat, using immunocytochemistry combined with knife-cut and lesion experiments. The VT had a dense plexus of L-ENKLI fibers but no L-ENKLI cells. Destruction of the dorsal premammillary nucleus and medial mammillary nucleus pars medialis, which contained a large group of L-ENKLI neurons, markedly reduced L-ENKLI fibers in the ipsilateral VT, suggesting that most of these fibers originate in these nuclei. The DDT contained a large collection of L-ENKLI neurons together with dense L-ENKLI fibers. Destruction of the DDT caused a contralateral marked reduction of L-ENKLI fibers in the dorsolateral part of the interpeduncular nucleus (DL), suggesting that L-ENKLI neurons in the DDT project contralaterally to the DL. L-ENKLI fibers in the DDT may be of intrinsic origin.
Yamano
M
M
Tohyama
M
M
D000818:Animals; D001931:Brain Mapping; D004743:Enkephalin, Leucine / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006651:Histocytochemistry; D009434:Neural Pathways / Q000378:metabolism; D051381:Rats; D013681:Tegmentum Mesencephali / Q000033:anatomy & histology / Q000378:metabolism*
D004743:Enkephalin, Leucine