Electrophysiological Studies of Thermal and Taste Reception in Chickens and Pigeons.

Abstract

Abstract. The impulse traffic in thermal and taste nerve fibres from the tongue of chickens and pigeons were analyzed while applying adequate stimuli to the tongue. Receptors were found in the tongue and pharynx which respond, in general, like those found in mammals. The thermal and taste receptors discharge through two peripheral branches of the 9th nerve only. In the chicken positive responses from the nerves followed the application of distilled water, salt, glycerine, ethylene glycol, quinine and acetic acid to the tongue but not of sucrose and saccharine. The taste responses in the pigeon's nerves were similar with the exception that no responses were observed to quinine and that 50 per cent of the pigeons responded positively to saccharine although sucrose was ineffective. In both species large number of “cold fibres” were observed while warming the tongue gave no response until the temperature was raised to above 45° C. This indicated the absence of “warm fibres” and suggested that the activity observed was due to stimulation of “pain fibres”. These direct studies of taste nerve activity were compared with recent behavioural studies in chickens and pigeons.