Sensory innervation of the brain - myth or reality?

This article provides a critical analysis of the concepts of the sensory innervation of the brain and spinal cord presented in Sotnikov's articles in issues 2 and 3 of this volume. Criteria for the identification of intracerebral primary sensory neurons and the possible roles of neuronal cilia are discussed. The significance of asynaptic dendrites and bipolar cells is considered. The importance of the correct use of a variety of terms is emphasized, and the need for using combined morphological and electrophysiological analysis in investigating sensory intracerebral exteroceptors is noted.