コイ側線器官(孔器)の炭酸ガス応答

抄録

The responsiveness of free neuromasts (pit organs), innervated by a buccal branch of the anterior lateral line nerve, the ramus buccalis, in the carp Cyprinus carpio to carbon dioxide dissolved in distilled water was studied using whole nerve and single unit recording techniques.
The stimulation of the carp pit organ with CO₂ solution produced a large phasic response followed by a long period (60-90s) of depression in impulse discharges. These temporal patterns of integrated responses were CO₂-specific and differed from those of various acids, in which an initial phasic response was followed by a plateau level of neural activity sustained during the stimulation.
The magnitude of the CO₂ responses was slightly pH-dependent, suggesting that dissolved free CO₂ may have a facilitating effect on the receptor cell.
All the single units tested responded to CO₂ and other acids with response patterns similar to those in whole nerve recordings. No specicfic single units responding to CO₂ alone were detected, showing the receptor cells to be 'generalist' in nature.