title: Multiple messengers in descending serotonin neurons: localization and functional implications.
abstract: In the present review article we summarize mainly histochemical work dealing with descending bulbospinal serotonin neurons which also express a number of neuropeptides, in particular substance P and thyrotropin releasing hormone. Such neurons have been observed both in rat, cat and monkey, and may preferentially innervate the ventral horns of the spinal cord, whereas the serotonin projections to the dorsal horn seem to lack these coexisting peptides. More recent studies indicate that a small population of medullary raphe serotonin neurons, especially at rostral levels, also synthesize the inhibitory neurotransmitter gamma-amino butyric acid (GABA). Many serotonin neurons contain the glutamate synthesizing enzyme glutaminase and can be labelled with antibodies raised against glutamate, suggesting that one and the same neuron may release several signalling substances, causing a wide spectrum of post- (and pre-) synaptic actions.
authors.affiliation: Department of Neuroscience, Karolinska Institutet, Box 60 400, 171 77, Stockholm, Sweden. tomas.hokfelt@neuro.ki.se
authors.forename: T
authors.initials: T
authors.lastname: Hökfelt
authors.forename: U
authors.initials: U
authors.lastname: Arvidsson
authors.forename: S
authors.initials: S
authors.lastname: Cullheim
authors.forename: D
authors.initials: D
authors.lastname: Millhorn
authors.forename: A P
authors.initials: AP
authors.lastname: Nicholas
authors.forename: V
authors.initials: V
authors.lastname: Pieribone
authors.forename: K
authors.initials: K
authors.lastname: Seroogy
authors.forename: B
authors.initials: B
authors.lastname: Ulfhake
mesh_terms: D000818:Animals; D002415:Cats; D000882:Haplorhini; D008526:Medulla Oblongata / Q000166:cytology* / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D009479:Neuropeptides / Q000032:analysis* / Q000502:physiology; D051381:Rats; D012701:Serotonin / Q000032:analysis / Q000502:physiology*; D013116:Spinal Cord / Q000166:cytology* / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000032:analysis / Q000502:physiology
chemical_list: D009479:Neuropeptides; D012701:Serotonin; D005680:gamma-Aminobutyric Acid