NEUROSECRETORY PROCESSES EXTENDING INTO THIRD VENTRICLE: SECRETORY OR SENSORY?

"Dendrites" projecting into the third ventricle from hypothalamic neurosecretory neurons of the Pacific tree frog, Hyla regilla, appear to be morphologically equipped to serve both secretory and sensory functions. These cell processes contain elementary neurosecretory granules, Golgi membranes, mitochondria, and endoplasmic reticulum, suggesting synthesis and possibly release of hormonal material. Each "dendrite" is provided with a single cilium which has an accessory centriole and a striated rootlet.