Ciliated neurons in the paraventricular nuclei in old hamsters.

The ciliated neurons of the paraventricular nuclei in old hamsters have been studied by electron microscope. These neurons exhibit cilia of 9 + 0 pattern. The single cilia, emerging from typical basal bodies, project into the intercellular space in parallel to the plasmalemma. The basal bodies are connected to ciliary rootlets and close to the Golgi complex. Double or single centrioles in different locations, frequently related to rootlets, can be observed. From a morphological point of view we suggest that these cilia, in the aging process, may represent a sensory structure which could perceive stimuli from the intercellular space.