[Primary sensory neurons in the central nervous system]

Abstract

This paper summarizes the results of author's personal observations and the literature data on exteroceptive and some interoceptive neurons of the brain and spinal cord, such as Hesse's intraspinal ocelli, light-sensitive epiphyseal and ependymal neurons. Also described are the light-sensitive ganglion neurons of invertebrates, true bipolar sensory neurons inside the spinal cord, primary chemo- and thermosensitive neurons and sensory unipolar neurons, accompanying four thin Motavkin "central nerves", perforating spinal cord meninges and terminating with bush-like receptors near blood vessels or close to canalis centralis ependyma. The data on all known vertebrate intracerebral and intraspinal interoceptors are summarized in a unified scheme. The hypothesis is formulated, according to which animal and human central nervous system possesses its own sensory innervation, comparable to that one of the other organs, and contains local primary sensory neurons and their asynaptic dendrites, which may be divided into two groups: interoceptive and exteroceptive.