Nicotinic ACh receptors in area postrema neurons of immature rat brain.

The electrophysiological properties of nicotinic ACh receptors (nAChR) were investigated in acutely dissociated area postrema (AP) neurons of the immature rat brain using the whole-cell patch-clamp recording method. ACh induced a transient inward current exhibiting a strong inward rectification. The ACh response was mimicked by nicotine and cytisine, and was inhibited by nAChR antagonists, but not by 10(-7) M atropine. Muscarinic AChR agonists did not induce any current. We confirmed the Ca2+ permeability of nAChR. These results indicate the presence of nAChR on AP neurons, and suggest that the activation of nAChR play important roles in cardiovascular functions in rats.