Neurochemical changes in mouse DRGs and spinal cord after pelvic nerve axotomy (PNA)

TOMASELLA, M.E.; MALET, M; VIEYTES, C; GEBHART, GF; BRUMOVSKY, PR

Huerta Grande, Cordoba

Congreso; XXIIX CONGRESO ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACION EN NEUROCIENCIAS; 2013

Sociendad Argentina de Neurociencias

Peripheral neuropathies result in chronic pain and associated changes in the neurochemistry of primary afferent neurons. Most animal models on peripheral neuropathies target non-visceral nerves, while visceral ones are much less studied. In this study, lumbar 6 and sacral 1 spinal nerves, major tributaries of the primarily visceral pelvic nerve, were axotomized in BalbC mice. Sham animals were also included. Immunohistochemical expression of calcitonin gene related peptide (CGRP), transient receptor potential cation channel subfamily V member 1 (TrpV1), and cyclic AMP-dependent transcription factor 3 (ATF3), was analyzed seven days after surgery in L4-S2 dorsal root ganglia (DRG) and spinal cord. PNA resulted in a significant downregulation of CGRP- and TrpV1-immunoreactive (IR) L6-S1 DRG neuron profiles (NPs), in contrast to their abundant expression in uninjured DRGs (sham animals and contralateral to PNA). PNA also resulted in strong ATF3-IR DRG NPs upregulation. Small increases in ATF3-IR NPs were detected in sham animals and contralateral DRGs of some PNA mice. A modest decrease in CGRP like-immunoreactive primary afferents terminating in the dorsal horn of the spinal cord was observed ipsilateral to the lesion. Neurochemical alterations in mouse DRGs after injury of a predominantly visceral nerve are shown for the first time. If changes in these and other pain-related molecules contribute to pain associated to the injury of a visceral nerve, it remains to be established.