Dorsal Root Ganglion Cells and Their Processes

Abstract

General somatic primary afferent neurons have an especially important place in considerations of spinal sensory mechanisms. These neurons are housed in dorsal root ganglia and their cranial nerve equivalents. At spinal levels they are referred to as dorsal root ganglion cells (DRG cells). These cells are unipolar neurons (sometimes called pseudounipolar since they originated as bipolar cells, [Dogiel, 1908; Ranson, 1912]) with a peripheral process or processes that receive information from sensory receptor organs and a central process or processes that transmit this information centrally (Fig. 3.1). Thus, we can divide the primary afferent neuron into a cell body, a peripheral process or processes, and a central process or processes. The central processes are often referred to as dorsal root axons because they travel in the dorsal root on their way to the cord.