CHANGES IN CALBINDIN-CONTAINING NEURONS IN THE POSTERIOR HORNS OF THE GRAY MATTER OF THE SPINAL CORD AND IN THE SENSORY GANGLION OF THE SPINAL NERVE IN ALBINO RAT AFTER SENSORY DEPRIVATION

Abstract

An immunohistochemical method was used to study the effect of capsaicin treatment on morphometric and structural characteristics of neurons containing 28 kDa calbindin (CAB) in the posterior horns of the spinal cord (SC) gray matter T II segment and in the sensory ganglion of the second thoracic spinal nerve (SGSN) in Wistar rats (n=4). Capsaicin was administered to adult animals 3 times with an interval of 24 hrs, in a total dose of 125 mg/kg, the material was taken on the 14th day. The administration of capsaicin caused a decrease in the proportion of CABimmunopositive (CAB-IP) neurons in SGSN (by 60%) and in dorsal horn laminas I-II-III (by 8, 18 and 15%, respectively), while the average size of CAB-IP neurons increased due to intracellular edema. As a result of deafferentation, similar morphometric and structural changes of CAB-IP neurons developed in both SGSN and posterior horn of SC gray matter, which were manifested by the central chromatolysis, vacuolation of nucleus and cytoplasm indicative of hydropic dystrophy. The irreversibility of the changes observed in the neurons of SGSN and SC dorsal horn laminas I, II and V was supported by the observations of their nuclear deformation, lysis of nucleolus, reduction of the number of CAB-containing neurons, signs of neuronophagia with the formation of residual nodules in place of the dead cells.

Keywords

spinal cord / dorsal horn / spinal ganglion / neurons / calbindin

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