Exposure to environmental enrichment prior to a cerebral cortex stab wound attenuates the postlesional astroglia response in rats

Abstract

Modulation of astroglial components involved in reactive postlesional responses in the rat cerebral cortex was analyzed following exposure to environmental enrichment (EE) condition prior to injury. For this purpose, changes in % immunoreactive (IR) area of GFAP, vimentin, EAAT1 and ezrin were evaluated in the perilesional zone after placing a cortical stab wound in the visual cerebral cortex of adult rats. GFAP-IR postlesional reactive astrocytosis in the perilesional cortex was significantly lower in the animal group exposed to EE during postnatal development. This GFAP-IR reaction seems to be associated with existing astroglia, because neither BrdU- nor endogenous Ki-67-labeled nuclei were found in the perilesional cortex analyzed. Increased ezrin-IR area in the visual cortex of rats exposed to EE condition suggests the formation of new synapses or the enhancement of astroglial involvement in the existing ones. No effects of EE were found on either EAAT1- or vimentin-IR area. Results suggest that exposure to EE conditions prior to injury attenuates the postlesional astroglia GFAP-response in the perilesional cortex of rats. Whether this attenuated postlesional astroglia GFAP-response promotes or not protective effects on the cortical neuropil remains to be explored in futures studies.