Evidence for transmitter similarity of two classes of mechanoreceptor neurons in the cerebral ganglion of Aplysia.
The cerebral ganglion was previously found to contain two classes of mechanoreceptor cells. In response to serotonin, one class exhibits spike narrowing, whereas the other class exhibits spike broadening. In the current study we report that at least some members of each class are immunopositive to sensorin, a peptide previously identified in other mechanoafferents that exhibit spike broadening to serotonin. Furthermore, the EPSPs evoked by the cerebral mechanoafferent neurons that exhibit spike narrowing to serotonin are blocked by the glutamate blocker DNQX. DNQX similarly blocks the EPSPs evoked by an interneuron (cerebral to buccal interneuron 1: CBI-1) that is excited by the mechanoafferents. The data provide evidence that although cerebral mechanoafferent neurons form a sharp dichotomy in terms of their response to serotonin, they may be related to one another in terms of their primary and cotransmitters.
Gapon
S
S
Center for Neurobiology and Behavior, Columbia University College of Physicians and Surgeons, NY 10032, USA.
Kupfermann
I
I
D000818:Animals; D001048:Aplysia / Q000502:physiology*; D004594:Electrophysiology; D005455:Fluorescent Antibody Technique; D017952:Ganglia, Invertebrate / Q000737:chemistry / Q000166:cytology; D008465:Mechanoreceptors / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009479:Neuropeptides / Q000032:analysis; D011810:Quinoxalines / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology
D009479:Neuropeptides; D011810:Quinoxalines; D012702:Serotonin Antagonists; C056723:FG 9041