MODULATORY ROLE OF ACETYLCHOLINE IN THE RAT PINEAL-GLAND

The function of acetylcholine (ACh) in the mammalian pineal gland is u nknown. To test the hypothesis that ACh exerts a modulatory role in th is organ, in the present study electrophysiogical multiunit recordings were carried out in ex-vivo rat pineal glands superfused with differe nt drugs. It was found that ACh (10(-7) M) as well as the cholinergic agonists oxotremorine (10-7 M) and nicotine (10(-6) M) increased the d ischarge rates of most of the spontaneously active units and led to bu rst activity in previously regularly firing cells. It is concluded tha t ACh may play a modulatory role in the pineal by influencing the firi ng of a special population of pineal cells with perhaps receptor funct ion. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.