Possible cholinergic neurotransmission in the cristae ampullares of the chick inner ear.

The presence of choline acetyltransferase (ChAT) was investigated in the chick inner ear in order to assess the possible role of acetylcholine (ACh) in neurotransmission within the vestibular labyrinth. ChAT activity found in homogenates of isolated chick vestibular cristae ampullares is of the same order of magnitude and has similar properties as its homologous enzyme in nervous tissue from various regions. These findings are in accord with a probable neurotransmitter role of ACh in the chick vestibular labyrinth.