Neurochemical and immunocytochemical studies of serotonin in the Hermissenda central nervous system.
In the preceding paper we showed that serotonin mimics the effects of associative conditioning on Type B photoreceptors of Hermissenda. Here we show that serotonin is present in the Hermissenda central nervous system, and that it is released in a calcium-dependent manner. A large number of serotonergic cell bodies are present in the cerebropleural ganglia (CPG). Cell bodies in the CPG are located in three small, symmetrical clusters. One cluster (2-3 cells) located at the anterior end of the CPG contains a large cell that projects to the buccal ganglion. A second cluster (2-3 cells) is located posterior to the first and near the midline of the nervous system. A third cluster (1-2 cells) was located slightly more posteriorly than the second. Type B photoreceptors and the S/E optic ganglion cell project to a region of the CPG neuropil which is heavily innervated by serotonin immunoreactive fine processes. Since serotonin mimicked the effects of associative conditioning on Type B cells, and is present in an appropriate region of the CPG neuropil, serotonin may mediate some effects of associative conditioning on Type B cells. Results supporting this hypothesis are presented in an accompanying paper.
Auerbach
S B
SB
Department of Biological Sciences, Nelson Laboratory, Rutgers University, Piscataway, NJ 08854.
Grover
L M
LM
Farley
J
J
D000818:Animals; D002490:Central Nervous System / Q000166:cytology / Q000378:metabolism*; D007150:Immunohistochemistry; D008974:Mollusca / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism*
D012701:Serotonin