Adolescent chronic stress has been shown to induce functional, biochemical and morphological modifications of the hippocampus, leading to stress-related disorders in adulthood. The present study investigated the effects of exercise, crocin and their combination on spatial learning and memory impairment and dendritic retraction of the CA3 pyramidal neurons induced by chronic adolescent stress in adult male rats. Rats were exposed to restraint stress 2 h/day for 10 days during postnatal days (PNDs) 30-40. Following this period, separate groups of animals were treated with crocin (25 and 50 mg/kg), exposed to running wheel, and or received the combined treatment during PNDs 41-55. Following the interventions, plasma levels of corticosterone, spatial learning and memory, apical dendritic length of CA3 pyramidal neurons and BDNF levels in the CA3 area were assessed. Findings showed that adolescent stress significantly increased corticosterone levels and reduced CA3 BDNF levels. Adolescent stress also impaired spatial learning and memory, and retracted apical dendritic length of CA3 pyramidal neurons. Crocin, voluntary exercise, and their combination recovered stress-induced spatial learning and impairment and CA3 pyramidal neurons dendritic length retraction. All treatments also reduced significantly corticosterone levels and enhanced CA3 BDNF levels in the stress groups. Finally, these treatments even increased apical dendritic length of CA3 pyramidal neurons in the non-stress groups. These findings indicate that detrimental effects of adolescent stress on cognitive function and hippocampal morphology in adulthood could be restored by early interventions with physical activity and crocin treatment during adolescent period.

已证明青少年慢性压力会诱导海马体的功能、生化和形态改变，导致成年后与压力相关的疾病。本研究调查了运动、藏红花素及其组合对成年雄性大鼠慢性青少年应激引起的空间学习和记忆障碍以及 CA3 锥体神经元树突收缩的影响。在产后天 (PND) 30-40 期间，大鼠暴露于束缚压力 2 小时/天，持续 10 天。在此期间之后，不同组的动物接受藏红花素（25 和 50 毫克/千克）治疗，暴露于跑步轮，和/或在 PND 41-55 期间接受联合治疗。干预后，血浆皮质酮水平，空间学习和记忆，评估了 CA3 锥体神经元的顶端树突长度和 CA3 区域的 BDNF 水平。结果表明，青少年压力显着增加皮质酮水平并降低 CA3 BDNF 水平。青少年压力也会损害空间学习和记忆，并收缩 CA3 锥体神经元的顶端树突长度。藏红花素、自愿运动及其组合恢复了压力引起的空间学习和损伤以及 CA3 锥体神经元树突长度收缩。所有治疗还显着降低了应激组的皮质酮水平并增强了 CA3 BDNF 水平。最后，这些治疗甚至增加了非压力组中 CA3 锥体神经元的顶端树突长度。