The integration of feeding-related sensory inputs by cerebral to buccal interneurons (CBs) was examined in preparations consisting of the isolated CNS attached to the sensory receptors on the lips. Responses of CBs to tactile stimulation of the lips were dependent upon what portion of the lip was stimulated. Generally responses of phasic CBs to touch of the outer surface of the lip were inhibitory while responses to touch of the inside of the mouth were excitatory. The tonic CBs, CBST and CBEPSP, were strongly excited by touch of the inner or outer lip. Responses of CBs to chemostimuli applied to the lip paralleled those of intact slugs. Chemostimuli such as fructose or food-plant extracts which stimulate feeding in intact slugs excited CBs while chemostimuli aversive to intact slugs, quinidine sulfate and citric acid, inhibited phasic CBs. Some CBs appear to be monosynaptically connected to taste-sensory afférents in the CG while others are more indirectly connected. Synaptic inputs to CBs which are phase-locked to the feeding rhythm and characteristic of phasic CBs, were found to be dependent upon an intact ipsilateral cerebral buccal connective and are the result of phasic activity of neurons in the buccal ganglia, not the cerebral ganglia. Strong electric shock of the foot of intact slugs causes an immediate withdrawal response and inhibition of feeding behavior and responsiveness to food lasting several minutes. Brief electric shock of foot tissue in vitro inhibits CBs and fictive feeding and blocks or reduces the ability of attractive taste stimuli to excite CBs and initiate fictive feeding for up to 10 min. This offers the possibility of studying a neuronal correlate of behavioral sensitization in this in vitro preparation.
All Science Journal Classification (ASJC) codes
- Ecology, Evolution, Behavior and Systematics
- Animal Science and Zoology
- Behavioral Neuroscience