The Infundibular Cerebrospinal-Fluid Contacting Neurons

The infundibular region forms an important part of the hypothalamic peri- ventricular grey substance. By morpho-physiological examinations its nuclei were affirmed to be generally significant as high-leveled centres for the regulation of various vegetative functions: heart frequency, blood pressure, intestine motility, feeling of hunger, satiety and thirst, and homeostasis of temperature. Moreover, emotional and sexual reactions as well as the regulation of behaviour depend on the hypothalamic nuclei. Most frequently, researchers dealt with the role of the neurosecretory supraoptic, paraventricular and infundibular nuclei for water and salt household and for the control of endocrine glands. Furthermore, the hypothalamus, especially its ventricular wall was suggested by a series of physiological studies to have different receptory functions like osmoreception, glucose reception, thermoreception etc. (Verney, 1947; Hellon, 1972; Andersson, 1972, a.o.). However, the morphological investigation of the corresponding receptor structures remained far behind for a considerable time. Our present contribution demonstrating a special hypothalamic neuron type seems to be closely connected exactly with this morphological problem.