ISSN:
1432-1351
Keywords:
Terrestrial slug
;
Buccal ganglia
;
Radular mechanosensory neuron
;
Phase-dependent spike broadening
;
Synaptic facilitation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract A radular mechanosensory neuron, RM, was identified in the buccal ganglia of Incilaria fruhstorferi. Fine neurites ramified bilaterally in the buccal ganglia, and main neurites entered the subradular epithelium via buccal nerve 3 (n3). When the radula was distorted by bending, RM produced an afferent spike which was preceded by an axonic spike recorded at n3. The response of RM to radular distortion was observed even in the absence of Ca2+, which drastically suppressed chemical synaptic interactions. Therefore, RM was concluded to be a primary radular mechanoreceptor. During rhythmic buccal motor activity induced by food or electrical stimulation of the cerebrobuccal connective, RM received excitatory input during the radular retraction phase. In the isolated buccal ganglia connected to the radula via n3s, the afferent spike, which had been evoked by electrical stimulation of the subradular epithelium, was broadened with the phasic excitatory input. Since the afferent spike was also broadened by current injection into the soma, depolarization due to the phasic input may have produced the spike broadening. Spike broadening was also observed during repetitive firing evoked by current injection. The amplitude of the excitatory postsynaptic potential in a follower neuron increased depending on the spike broadening of RM.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00192012
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