Intermediate filament expression in the cervical spinal cord of rats after intraparenchymal injection of kainic acid

NISHIDA F; SISTI S; ZANUZZI CN; BARBEITO CG; PORTIANSKY EL

Congreso; XXX Congreso anual de la Sociedad Argentina de Investigación en Neurociencias; 2015

Pathological features of many neurodegenerative diseases include synaptic loss, dendrite retraction and neuronal degeneration and death. It was recently reported that neuronal intermediate filaments (IF) play a central role in damage-response mechanisms by activating a developmental program to differentiate neurons and to establish synaptic connections. The goal of the present work was to evaluate IF immunohistochemical changes induced by an intraparenchymal injection of kainic acid (KA) into the rat cervical spinal cord. Male rats were injected with 1 mM of KA at the C5 segment. Saline-treated animals were used as sham and non-operated rats as control group. Rats were sacrificed either at days 1, 2, 3 or 7 post-injection (pi). Anti-neurofilament (NF) and anti-vimentin (VIM) antibodies showed positive labeling for neuronal projections and ependymal and endothelial cells in control group, respectively. Besides, anti-GFAP labeled all glial cells. Sham rats showed anti-VIM and anti-NF positive labeling of perikarya for the first two days pi. Perikarya of KA-treated animals showed positive labeling for VIM and NF throughout the experiment, whereas GFAP reactivity was observed only for the first two days pi. These results suggest that in the perikarya of treated rats there is an unconventional IF expression, which may respond to the neuronal damage induced by the mechanical injury and the KA to reestablish synaptic connections lost during the neurodegenerative process.