TYPES AND SUBTYPES OF NEURONS IN DORSAL-ROOT GANGLIA OF THE LIZARD PODARCIS-SICULA - A LIGHT AND ELECTRON-MICROSCOPE STUDY

A morphological analysis of types and sub-types of neurons from dorsal root ganglia at different spinal levels was carried out by combined l ight and electron microscopy in Podarcis sicula. Two neuron types were recognized: small dark cells (type D) and large light cells (type L). Type L cells were further sub-divided into three sub-types (L1, L2, L 3) on the basis of entity and distribution of neurofilaments. Percenta ge distribution of neuron types did not vary in relation to the spinal level. ON the contrary, differences were found in the percentage of t he three type L neuron sub-types; a higher percentage of cells very ri ch in neurofilaments (L2,L3) was found in dorsal root ganglia from the cervical and the lumbar spinal levels. Results are discussed in relat ion to the spinal-level-related extent of innervation territory of dor sal root ganglia.