Enriched environment and antidepressant treatment during juvenility overcome the memory deficits and depressive-like behavior induced by early adverse stress / 中华行为医学与脑科学杂志

ABSTRACT

Objective To explore the effect of postweaning enriched environment and citalopram treatment during juvenility on the behaviour of male rats exposed to early adverse stress. Methods The newborn pups were randomly divided into maternal separation group (MS) and non-maternal separation group (NMS). Offspring were weaned on PND22 and housed in same-rearing groups under either standard or enriched conditions or citalopram treatment until adulthood. All of them were examined by sucrose consumption test, forced swimming test (FST) and morris water maze test (MWZ). Results (1) MS had significantly less consumption of sucrose intake (ml/g)(0.013 ±0.006, n = 10), compared with the following five groups (MS + EE (0.023 ±0.012, n = 8); MS + Drug (0.027 ±0.012, n = 9); NMS (0.022 ± 0. 007, n=11);NMS + EE (0.023 ±0.007, n = 7); NMS + Drug (0.032 ±0.011),n=7)), NMS + Drug had significantly increased the radio of sucrose consumption on NMS group. (2)The immobility in FST were longer in MS-experienced groups (MS (140. 19 ± 37.01) s, n = 8); MS + EE (129.41 ±29.50)s, n = 6) ;NMS + Drug (128.83 ±26. 11)s, n = 6)) than three non-MS groups (NMS (96.28 ±35.63)s,n = 7); NMS + EE (94.17 ±24. 87)s, n = 6) ;NMS + Drug (93.00 ±34. 21)s, n = 6)). (3) MS had shorter time and shorter percentage of distance spent in target quadrant in MWZ,citalopram treatment markedly improved spatial memory on NMS group. Conclusion Maternal separation applied in newborn rats induces a broad spectrum of behavioral changes reminiscent of depressive symptoms in humans, which might be reversed to some extent by EE and antidepressant in young adults.