Physiology of Finfish and Shellfish (2+1)

5.2.5. Neuro-endocrine regulation of the pituitary gland

Pituitary gland controls a number of metabolic activities of the fish through its hormones, but the secretion of its hormones is regulated by the hypothalamus of the brain. Studies have shown that nucleus preopticus (NPO) and the nucleus lateralis tuberis (NLT) are the important nuclear areas which control the activities of the pituitary. The NPO is situated dorsal to the optic chiasma and its axons (An axon is a long, slender projection of a nerve cell or neuron that conducts electrical impulses away from the neuron's cell body or soma) extend into the pituitary gland. The NLT lies along the ventral surface of the infundibulum and its neurons innervate the cells of the hypophysis. The hypothalamus controls the activities of the pituitary gland either through these axons directly or by transferring neuro-endocrine hormones through a hypothalamo-hypophysial blood portal system .

Extracts of the pituitary gland are extensively used in induced breeding of fishes in fish culture.