Olfactory epithelium: unitary responses in the tortoise.

In the tortoise, Gopherus polyphemus, single unit spikes in the olfactory epithelium in response to amyl acetate were positive relative to the slow potential. The number of spikes in a response train was 4 to 15, the duration 3 to 4 msec, the height 0.5 to 2 mv. The height of successive spikes in a train decreased. The decrement in height, the number, and the frequency of spikes changed with the strength of the odor.