Neuronal subpopulations present in the dorsal root ganglion

Abstract

Dorsal root ganglion (DRG) neurons main function is to convey sensory information from the periphery towards the central nervous system. Two kinds of cells are present in this ganglion: non-neurona1 cells and neurons. Morphological, functional and biochemical heterogeneity of the neuronal population makes it necessary to distinguish cellular subpopulations. There are three types of DRG neurons morphologically defined (A, B and C), according to their size and ultrastructural characteristics. There is a direct correlation behween cell size, diameter of the fibers and conduction velocity. Finally, a nurnber of markers such as neuropeptides, enzymes and receptors allow for a biochemical classification which is the most used for the study of the neuronal function. This paper reviews the experimental evidence on DRG neurons heterogeneity and presents a biochemical and physiological correlation in the cases when relevant information is available. Study of DRG neuron populations is relevant to different fields in neuroscience research, such as the study of neurotropic virus infection mechanisms, cellular and molecular biology of peripheral nerve injury and neurotrophic factors, among others.