Involvement of amygdalar receptors in the control of anterior pituitary function

Drugs stimulating adrenergic, cholinergic or serotoninergic receptors have been implanted in the basomedial area of the amygdala in long-term castrated female rats, which were sacrificed at different time intervals after implantation. The data obtained show that: α-adrenergic receptors present in the amygdala exert an inhibitory tone on LH and FSH secretion and a stimulatory one on prolactin release; amygdalar β-adrenergic receptors exert an inhibitory influence on LH secretion and a stimulatory one on prolactin; and cholinergic receptors of the muscarinic type exert an inhibitory influence on LH but not on FSH release. Receptors of the nicotinic type exert the opposite effect. Cholinergic receptors of the muscarinic type seem to participate in the stimulatory control of prolactin secretion, while nicotinic receptors exert an inhibitory influence on this hormone. Serotoninergic receptors exert a stimulatory action on LH and prolactin secretion.