Slice cultures confirm the presence of cholinergic neurons in the rat habenula.
The opinion that the medial habenular nuclei contain cholinergic perikarya has recently been questioned, mainly on the basis of the difficulty to detect choline acetyltransferase (ChAT) immunoreactivity in cell bodies of these nuclei. We decided therefore to determine ChAT activity in long-term cultures of the embryonal rat habenula. In these cultures, all extrinsic fiber systems are expected to degenerate a few days after explanation. ChAT activity increased markedly during the first 3 weeks. Control cultures of adjacent thalamic tissue, which is devoid of intrinsic cholinergic neurons, displayed a 150-fold lower ChAT activity. Immunocytochemical staining with a monoclonal antibody revealed the presence of tightly packed, ChAT-containing cell bodies in the habenular slices. These two findings, together with the observation that habenular cultures show an extensive outgrowth of acetylcholinesterase-containing fibers, lead us to the conclusion that at least some cholinergic perikarya must be present in the habenular nuclei.
D000110:Acetylcholinesterase / Q000378:metabolism*; D000818:Animals; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D002799:Cholinergic Fibers; D046508:Culture Techniques; D004027:Diencephalon / Q000166:cytology / Q000201:enzymology*; D006651:Histocytochemistry; D007124:Immunoenzyme Techniques; D051381:Rats
D002795:Choline O-Acetyltransferase; D000110:Acetylcholinesterase