5-HT(2A) receptor-like protein is present in small neurons located in rat mesopontine cholinergic nuclei, but absent from cholinergic neurons.
The cholinergic neurons of the pedunculopontine and laterodorsal tegmental nuclei (PPN and LDN) increase their activity during wakefulness and REM sleep and interact with brainstem neurons containing serotonin (5-HT) and other amines. To determine whether mesopontine neurons that contain nitric oxide synthase (NOS), a marker for cholinergic cells, express 5-HT(2A) receptors, dual immunostaining for 5-HT(2A) receptor-like protein and NOS was employed with either peroxidase or fluorescent secondary probes. Within the PPN and LDN, different cells expressed 5-HT(2A) receptors and NOS. In addition to the lack of co-localization, the 5-HT(2A) receptor-expressing cells were smaller and less numerous than the adjacent NOS neurons. We propose that 5-HT(2A) receptor-expressing cells are local inhibitory interneurons whose one function is to ensure the reciprocal patterns of activity in subpopulations of mesopontine cholinergic and aminergic neurons.
Fay
R
R
Department of Animal Biology 205ED/VET, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA 19104-4283, USA.
Kubin
L
L
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D000918:Antibody Specificity; D002452:Cell Count; D002799:Cholinergic Fibers / Q000378:metabolism* / Q000648:ultrastructure; D007150:Immunohistochemistry / Q000379:methods; D007395:Interneurons / Q000166:cytology / Q000378:metabolism*; D008297:Male; D009433:Neural Inhibition / Q000502:physiology*; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism; D011149:Pons / Q000166:cytology / Q000378:metabolism*; D011903:Raphe Nuclei / Q000166:cytology / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism; D012890:Sleep / Q000502:physiology; D009435:Synaptic Transmission; D013681:Tegmentum Mesencephali / Q000166:cytology / Q000378:metabolism*; D014851:Wakefulness / Q000502:physiology
D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin; D009569:Nitric Oxide; D012701:Serotonin; D019001:Nitric Oxide Synthase; D000109:Acetylcholine