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Journal of Experimental Biology, Vol 113, Issue 1 423-446, Copyright © 1984 by Company of Biologists
JOURNAL ARTICLES |
JA London and R Gillette
The paracerebral neurones (PCNs) of the brain of Pleurobranchaea californica serve a command role in the initiation of feeding behaviour (Gillette, Kovac & Davis, 1978). The PCNs are synaptically excited by food stimuli applied to the oral veil of hungry, naive animals. In food avoidance-conditioned animals, the PCNs are inhibited by a barrage of inhibitory postsynaptic potentials concomitant with the suppression of feeding (Davis & Gillette, 1978). In this paper, an interneuronal pathway is described which causes inhibition of the PCNs and potentially mediates the effects of learning. The inhibitory pathway consists of three serially connected interneurones. One population, designated the Interneurone 1s (Int-1s), monosynaptically inhibits the PCNs. A second population, the Interneurone 2s (Int-2s), excites the Int-1 population. They also excite other neurones of the brain including the metacerebral giant neurones. A third population, the Interneurone 3s (Int-3s), monosynaptically excites the Interneurone 2 population. Dual intracellular recordings and current injection show that ipsilateral members of the Int-2 population are electrically coupled via a nonrectifying connection. Contralateral members of the Int-2 population are excitatorily coupled via a polysynaptic pathway. The Int-1 population is phasically active during the rhythmic motor activity that underlies feeding. In the isolated nervous system Int-1 activity is phase-locked with rhythmic PCN activity; Int-1 activity occurs maximally at the end of a PCN burst, during the retraction phase of the cycle. Int-2 activity also occurs during the retraction phase. During actual feeding in the whole animal preparation, the Int-2s are also phasically active; maximal excitation occurs during buccal mass retraction and maximal inhibition during protraction and the bite. Stimulated activity in a single Int-2 can entirely suppress the rhythmic motor activity of the feeding network evoked by electrical stimulation of the stomatogastric nerve. The suppressant effects of Int-2 activity must be mediated widely within the feeding network because the rhythmic motor output so driven is not dependent on PCN spiking. Application of an appetitive chemosensory stimulus to whole and semi-intact animal preparations initiated feeding and elicited excitation of the Int-1 and Int-2 populations. Noxious chemosensory stimuli, such as a dilute soap solution or ethanol, elicited oral veil withdrawal and inhibition of the Int-2s by multiple inhibitory postsynaptic potentials.(ABSTRACT TRUNCATED AT 400 WORDS)
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 J. Jing and R. Gillette Directional Avoidance Turns Encoded by Single Interneurons and Sustained by Multifunctional Serotonergic Cells J. Neurosci., April 1, 2003; 23(7): 3039 - 3051. [Abstract] [Full Text] [PDF]
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 C. J. H. Elliott and A. J. Susswein Comparative neuroethology of feeding control in molluscs J. Exp. Biol., April 1, 2002; 205(7): 877 - 896. [Abstract] [Full Text] [PDF]
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R. Gillette and J. Jing The Role of the Escape Swim Motor Network in the Organization of Behavioral Hierarchy and Arousal in Pleurobranchaea Integr. Comp. Biol., August 1, 2001; 41(4): 983 - 992. [Abstract] [Full Text] [PDF]
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 R. Gillette, R.-C. Huang, N. Hatcher, and L. L. Moroz Cost-benefit analysis potential in feeding behavior of a predatory snail by integration of hunger, taste, and pain PNAS, March 28, 2000; 97(7): 3585 - 3590. [Abstract] [Full Text] [PDF]
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 J. Jing and R. Gillette Escape Swim Network Interneurons Have Diverse Roles in Behavioral Switching and Putative Arousal in Pleurobranchaea J Neurophysiol, March 1, 2000; 83(3): 1346 - 1355. [Abstract] [Full Text] [PDF]
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J. Jing and R. Gillette Central Pattern Generator for Escape Swimming in the Notaspid Sea Slug Pleurobranchaea californica J Neurophysiol, February 1, 1999; 81(2): 654 - 667. [Abstract] [Full Text] [PDF]
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