Khodaie Babak, Lotfinia Ahmad Ali, Ahmadi Milad, Lotfinia Mahmoud, Jafarian Maryam, Karimzadeh Fariba, Coulon Philippe, Gorji Ali
Shefa Neuroscience Research Center, Khatam Hospital, Tehran, Iran; Faculty of Veterinary Medicine, Islamic Azad University Karaj Branch, Karaj, Iran.
Shefa Neuroscience Research Center, Khatam Hospital, Tehran, Iran; Medical School of Shahid-Beheshti Medical University, Tehran, Iran.
Behav Brain Res. 2015 Feb 1;278:55-65. doi: 10.1016/j.bbr.2014.09.034. Epub 2014 Sep 28.
Social isolation has significant long-term psychological and physiological consequences. Both social isolation and traumatic brain injury (TBI) alter normal brain function and structure. However, the influence of social isolation on recovery from TBI is unclear. This study aims to evaluate if social isolation exacerbates the anatomical and functional deficits after TBI in young rats. Juvenile male rats were divided into four groups; sham operated control with social contacts, sham control with social isolation, TBI with social contacts, and TBI with social isolation. During four weeks after brain injury in juvenile rats, we evaluated the animal behaviors by T-maze and open-field tests, recorded brain activity with electrocorticograms and assessed structural changes by histological procedures in the hippocampal dentate gyrus, CA1, and CA3 areas. Our findings revealed significant memory impairments and hyperactivity conditions in rats with TBI and social isolation compared to the other groups. Histological assessments showed an increase of the mean number of dark neurons, apoptotic cells, and caspase-3 positive cells in all tested areas of the hippocampus in TBI rats with and without social isolation compared to sham rats. Furthermore, social isolation significantly increased the number of dark cells, apoptotic neurons, and caspase-3 positive cells in the hippocampal CA3 region in rats with TBI. This study indicates the harmful effect of social isolation on anatomical and functional deficits induced by TBI in juvenile rats. Prevention of social isolation may improve the outcome of TBI.
社交隔离会产生重大的长期心理和生理后果。社交隔离和创伤性脑损伤（TBI）都会改变正常的脑功能和结构。然而，社交隔离对TBI恢复的影响尚不清楚。本研究旨在评估社交隔离是否会加剧幼鼠TBI后的解剖学和功能缺陷。将幼年雄性大鼠分为四组；有社交接触的假手术对照组、社交隔离的假对照组、有社交接触的TBI组和社交隔离的TBI组。在幼年大鼠脑损伤后的四周内，我们通过T迷宫和旷场试验评估动物行为，用电皮层电图记录脑活动，并通过组织学方法评估海马齿状回、CA1和CA3区域的结构变化。我们的研究结果显示，与其他组相比，TBI和社交隔离的大鼠存在明显的记忆障碍和多动情况。组织学评估显示，与假手术大鼠相比，有和没有社交隔离的TBI大鼠海马所有测试区域的暗神经元、凋亡细胞和caspase-3阳性细胞的平均数量均增加。此外，社交隔离显著增加了TBI大鼠海马CA3区域的暗细胞、凋亡神经元和caspase-3阳性细胞的数量。本研究表明社交隔离对幼鼠TBI诱导的解剖学和功能缺陷具有有害影响。预防社交隔离可能会改善TBI的预后。
