A conserved location for the central nervous system control of mating behaviour in gastropod molluscs: evidence from a terrestrial snail.
We have investigated the role of the right mesocerebrum in the expression of mating behaviour in the garden snail Helix aspersa. Using an in vivo stimulation and recording technique, we provide evidence for both sensory and motor functions in the mesocerebral neuronal population. Some neurones were specifically sensitive to tactile stimuli delivered to the skin on the superior tentacles and around the genital pore. Electrical stimulation of the right mesocerebrum evoked genital eversion and, in combination with tactile stimulation, dart-shooting and penial eversion. Genital eversions were also elicited by injections of APGWamide. During courtship, one recorded unit increased its activity only in correlation with penial eversion, while six other units increased their activity only during dart-shooting. Three additional units increased their activity during both types of behaviour. In addition, most of the recorded units showed increased neuronal activity during times of contact with a partner. Comparison of our results with available data from other molluscs leads us to conclude that the right anteromedial region of the cerebral ganglion is an evolutionarily conserved region of the gastropod brain specialised for the control of male mating behaviour. It is striking to find such functional conservation in the central nervous system of phylogenetically distant gastropods given the large differences in behaviour during mating.
Koene
J M
JM
Department of Biology, McGill University, Montréal, Québec, H3A 1B1 Canada and Faculty of Biology, Vrije Universiteit, De Boelelaan 1087, The Netherlands. jkoene@BIO1.LAN.mcgill.ca.
Jansen
R F
RF
Ter Maat
A
A
Chase
R
R
D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology; D004558:Electric Stimulation; D017952:Ganglia, Invertebrate / Q000033:anatomy & histology / Q000502:physiology; D006372:Helix, Snails / Q000033:anatomy & histology* / Q000502:physiology*; D008297:Male; D009479:Neuropeptides / Q000494:pharmacology; D018377:Neurotransmitter Agents / Q000494:pharmacology; D010812:Physical Stimulation; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology*
D009479:Neuropeptides; D018377:Neurotransmitter Agents; C063193:alanyl-prolyl-glycyl-tryptophanamide