Joushi Sara, Esmaeilpour Khadijeh, Masoumi-Ardakani Yaser, Esmaeili-Mahani Saeed, Sheibani Vahid
Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran.
Physiology Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Kerman, Iran.
J Neurosci Res. 2021 Dec;99(12):3373-3391. doi: 10.1002/jnr.24974. Epub 2021 Oct 22.
Early-life experiences, including parental care, affect cognitive performance later in life. Being exposed to early-life maternal separation (MS) increases susceptibility to stress-related psychopathology. Previous studies suggest that MS could induce learning and memory impairments. Since enriched environment (EE) provides more opportunities for exploration and social interaction, in the present study we evaluated the effects of a short EE paradigm with a duration of 13 days on cognitive abilities of maternally separated rats (MS; 180 min/day, postnatal day (PND) 1-21) during adolescence in four experimental groups: Control, Control+EE, MS, and MS+EE. Plasma corticosterone (CORT) and brain-derived neurotrophic factor (BDNF) levels were also measured in experimental animals. We also studied the induction of long-term potentiation (LTP) in the slices of hippocampal CA1 area. The behavioral and electrophysiological assessments were started at PND 35. MS caused higher basal CORT levels in plasma and impaired spatial learning, memory, and social interaction. LTP induction was also impaired in MS rats and plasma BDNF levels were reduced in these animals. MS also induced more anxiety-like behavior. Short EE reduced plasma CORT levels had the potential to improve locomotor activity and anxiety-like behavior in MS+EE rats and reversed MS-induced impairments of spatial learning, memory, and social behavior. LTP induction and plasma BDNF levels were also enhanced in MS+EE rats. We concluded that short EE might be considered as a therapeutic strategy for promoting cognition.
早期生活经历，包括父母的照料，会影响日后的认知表现。早年经历母婴分离（MS）会增加患应激相关精神病理学疾病的易感性。先前的研究表明，母婴分离可能会导致学习和记忆障碍。由于丰富环境（EE）提供了更多探索和社交互动的机会，在本研究中，我们在四个实验组中评估了为期13天的短期丰富环境模式对青春期母婴分离大鼠（MS；每天180分钟，出生后第1天至第21天）认知能力的影响：对照组、对照组+丰富环境组、母婴分离组和母婴分离+丰富环境组。我们还测量了实验动物的血浆皮质酮（CORT）和脑源性神经营养因子（BDNF）水平。我们还研究了海马CA1区切片中长时程增强（LTP）的诱导情况。行为和电生理评估在出生后第35天开始。母婴分离导致血浆中基础CORT水平升高，并损害空间学习、记忆和社交互动。母婴分离大鼠的LTP诱导也受损，且这些动物的血浆BDNF水平降低。母婴分离还会诱发更多类似焦虑的行为。短期丰富环境可降低血浆CORT水平，有可能改善母婴分离+丰富环境组大鼠的运动活动和类似焦虑的行为，并逆转母婴分离引起的空间学习、记忆和社交行为障碍。母婴分离+丰富环境组大鼠的LTP诱导和血浆BDNF水平也有所提高。我们得出结论，短期丰富环境可被视为促进认知的一种治疗策略。
