EFFECT OF EARLY LIFE STRESS ON THE VISUAL SYSTEM IN ADULT MICE

ROSENSTEIN, RUTH E.; DIEGUEZ, HERNÁN H.; BERNAL AGUIRRE, NATHALY; DORFMAN, DAMIÁN; CALANNI, JUAN S.

Mar del Plata

Congreso; REUNIÓN CONJUNTA SAIC SAI&FAIC SAFIS 2022; 2022

SAIC, SAI, FAIC, SAFIS

Early life stress is defined as a period ofsevere and/or chronic trauma, as well asenvironmental/social deprivation or neglect in pre/postnatal stage. Presently, the impact of ELS on thevisual system in the adult stage isunknown. Using an animal model of maternal separationwith early weaning (MSEW), which mimics early life neglect, we analyzed the long-term ELSconsequences in the visual system.Mice were separated from the dams for 2 h at postnatal days(PNDs) 2-5, for 3 h at PNDs 7-9, for 4 h at PNDs 10-13, for 6 hat PNDs 14-16, and weaned at PND17. At the end of each separation period, mothers were subjected to movementrestriction for 10 min. Control pupswere left undisturbed from PND0, and weaned atPND21. At PND 65-70, MSEW did not affect the body weight or theelectroretinogram a- and b-wave amplitude, but significantly decreasedscotopic threshold response (STR, P<0.01),photopic negative response(PhNR, P<0.01), and visual evoked potential amplitude(P<0.01). MSEW did no change thethickness of retinal layers, butsignificantly decreased synaptophysin content (assessed byimmunohistochemistry and Western blot, P<0.05), and Brn3a(+) retinal ganglion cell (RGC) number (assessed byimmunohistochemistry and Western blot, P<0.01). Moreover, MSEWsignificantly increased Iba-1(+)area, and Iba-1(+) cell soma size (by immunohistochemistry, P<0.01),consistently with an increased numbers of amoeboidmicroglial cells. MSEW increased plasmatic corticosterone levels at PND10 (P<0.01). Mifepristone (injectedevery 3 days between PNDs 4-16)significantly prevented the effect of MSEW on STR(P<0.01), and PhNR amplitude (P<0.01), and preserved RGC Brn3a(+)cell number, Iba-1(+) area, and Iba-1(+) cell soma size (P<0.01). These results suggestthat retinal alterations might be included among thechildhood adversity-induced threats to life quality, whichcould be prevented by an early pharmacological intervention withmifepristone.