Brain-derived neurotrophic factor in the hypothalamo-hypophyseal system of Xenopus laevis.

Brain-derived neurotrophic factor (BDNF) is immunocytochemically demonstrated in the magnocellular nucleus and neural lobe of the pituitary gland of the amphibian Xenopus laevis. Immunoelectron microscopy shows BDNF in secretory granules of type A neurohemal axon terminals in the neural lobe of pituitary gland. It is proposed that BDNF released from the neural lobe acts as a neurohormone stimulating the secretory activity of the melanotrope cells in the intermediate pituitary lobe.