The psychopharmacology of the human pineal

In many ways the pineal is an ideal endocrine gland for the biological psychiatrist. The gland is small, circumscribed and relatively homogeneous, so it can be studied either in tissue culture or in vivo. The results from such studies combine to give a well-characterized model for investigating noradrenergic neurotransmission. In the pineal as in the brain there is a noradrenaline uptake site, an autoreceptor which regulates noradrenaline release, and there are post-junctional β(1) and α(1)-adrenoceptors. In the pineal as in the brain the β(1) adrenoceptor is linked to adenylate cyclase and the α( 1)-adrenoceptor is coupled with phos phatidyl inositol (PI) turnover: both second messenger systems combine to influence mela tonin secretion.