Interface Properties of Circumventricular Organs in Salt and Fluid Balance.

The "sensory" circumventricular organs, with their leaky blood-brain barriers, permit contact between brain neurons and blood-borne molecules. Body fluid balance and cardiovascular control involve established interface functions of subfornical organs. Their recently identified target functions for hormones released during digestion suggest that they may coordinate fluid and food intake.

Spinal neuronal thermosensitivity in vivo and in vitro in relation to hypothalamic neuronal thermosensitivity.

In the spinal cord, temperature signals are generated which serve as specific inputs in the central nervous control of body temperature. Because of the spatially distinct organization of afferent and efferent neuronal systems at the spinal level, the afferent pathway for temperature signal transmission could be identified in vivo in the ascending, anterior and lateral tracts with a relationship of about 75:25% between warm and cold sensitive neuraxons. Analysis of spinal neuronal thermosensitivity in vitro on spinal cord tissue slices has been concerned, so far, with the superficial laminae of the dorsal horn as the site of origin of ascending nerve fibers conveying mostly temperature and pain signals, and with lamina X as a site of origin of afferent as well as efferent neurons.