Microglia and astrocyte reactivity in a rat spinal cord excitotoxic model.

SISTI, S; REGGIANI, PC; BARBEITO, C; NISHIDA, FABIAN; BELLINI, MJ; VON WERNICH, M; ZANUZZI, CN; FALOMIR LOCKHART, EUGENIA; CAMIÑA, A; PORTIANSKY, E

Mar del Plata

Congreso; XXXII Congreso Anual SAN; 2017

Different glial responses have been reported in kainic acid (KA)-induced excitotoxic models at the Central Nervous System. Our goal was to evaluate microglia and astrocyte number and morphological changes in an experimental excitotoxic model induced by the intraparenchymal injection of KA in the spinal cord. Male rats were injected either with 1 mM of KA (KA group) or saline (sham group) at the C5 segment and euthanized at days 1, 2, 3 or 7 post-injection (pi). Non-operated rats were used as intact controls. Total number of cells,morphological phenotype (microglia types I-V) and branches length (astrocytes) were evaluated. Immunohistochemistry/fluorescence using anti-IBA-1 and anti-GFAP antibodies were used to identify microglia and astrocytes, respectively. In the KA group, total microglia number significantly increased in comparison to controls along the experiment, and by day 3 pi in comparison to sham group. Types IV and V microglia increased by days 2 and 3 pi while types I and II did it by day 7. Astrocyte number was significantly higher at day 3 pi in shamand KA groups in comparison to controls, and their global branch length was longer in KA group than that of sham rats at days 2 and 3 pi. We found that microglia and astrocytes are morphologically reactive in the spinal cord under the KA-excitotoxicity model. Further molecular studies may define whether the glia is involved in the progression or the resolution of the neurodegenerative process in the present model.