Abstract
Adenohypophysial functions are controlled by neurohormones released from neurosecretory axon terminals within the external layer of the median eminence (ME) into the hypophysial portal blood. Cell bodies of the tubero-infundibular (TI) neurosecretory neurons projecting to the external layer of the ME have been identified in some nuclei of the medial basal hypothalamus (MBH) by an electrophysiological technique. This article reviews the recent electrophysiological studies on the distribution of antidromically identified TI neurons, efferent projections of TI axon collaterals, afferent neural connections to TI neurons, and neural pathways mediating recurrent inhibition and excitation in TI neurons.