GLIAL FIBRILLARY ACIDIC PROTEIN (GFAP) INCREMENTS ARE OBSERVED IN HIPPOCAMPUS OF CHRONIC RESTRAINT ANIMALS BUT NOT IN ANIMALS EXPOSED TO THE LEARNED HELPLESSNESS PARADIGM.

CLADOUCHOS MARÍA LAURA; SIFONIOS LAURA; CERESETO MARINA; FERNÁNDEZ MACEDO GEORGINA V.; WIKINSKI SILVIA

Tandil, Provincia de Buenoa Aires, Argentina

Congreso; XL Reunión Anual de la Sociedad Argentina de Farmacología Experimental.; 2008

Sociedad Argentina de Farmacología Experimental

Astrocytic changes in depression and in animal models of the disease are still poorly known. The main goal of this work was to investigate, by immunohistochemistry, the changes in GFAP in two experimental models of depression: the learned helplessness paradigm and the chronic restraint stress. Male adult rats were exposed to a protocol of either restraint stress (RS) (6 hours/day for 21 consecutive days) or inescapable shocks (LH) (one session of 60 footshocks lasting 15 sec each during 1 hour). In this latter model, 4 days after exposure to stress, animals were tested to identify those showing (LH+) or not showing (LH-) despair behaviour. The RS and their controls were sacrificed the day after concluding the protocol and the LH+, LH- and their controls (CLH) were sacrificed 4, 10 and 25 days after exposure to inescapable stress. Only RS animals showed a significant increment compared with their controls (RS: 50,9 %, p<0.001, unpaired Student’s t test). No differences were found in GFAP on days 4, 10 and 25 between CLH, LH+ and LH- animals. In the literature, experimental models of depression are usually considered to be equivalent. From our results, it seems that caution in these extrapolations should be advisable. Supported by: PICT 31953, PIP 5870, UBACYT M013 and M073.