Responses to Putative Second Messengers and Odorants in Water Nose Olfactory Neurons of Xenoput laevis

摘要

Using the whole-cell mode of the patch-clamp technique, we attempted to record inward currents in response to cAMF~ inositol 1 ,4,5-trisphosphate (1P3) and odorants from sensory neurons in the olfactory epithelium of the Xenopus laevis lateral diverticulum (water nose). Dialysis of 1 00 1iM of P3 induced inward currents, while dialysis of 1 mM of cAMP into olfactory neurons did not induce any response under the voltage-clamp conditions. Changes in membrane conductance were examined by applying ramp pulses. The slope of the current—voltage (l—V) curve during the P3-induced response was steeper than that after the response, indicating that P3 increased the membrane conductance. The water nose olfactory neurons have been shown to respond to both amino acids and volatile odorants. The slopes of I—V curves during responses to amino acids and a volatile odorant, lilial, were similar to those before the responses, suggesting that the total membrane conductance was not changed during responses to amino acids and the volatile odorant.