Caffeine is the most commonly used psychostimulant throughout the world, with its consumption being especially prevalent among adolescents and young adults, as over 75% of this group consumes caffeine daily. Similarly, the adolescent and young adult age group exhibit the highest incidence of traumatic brain injury (TBI). Given that both caffeine consumption and mild TBI (mTBI) are more prevalent among the late adolescent/young adult age group and that changes in dendritic spine morphology during this developmental period are poorly understood, this study sought to examine the effects of caffeine consumption during late adolescence/early adulthood on recovery from repetitive mTBI (RmTBI). The study specifically focused on changes to neuronal dendritic morphology as synaptic changes likely underlie long-term behavioral outcomes. The results demonstrate that during young adulthood caffeine consumption differentially affects the RmTBI outcomes of males and females, where the effects of caffeine and RmTBI were often additive in males while being equally detrimental, but rarely additive, in females. In general, caffeine and RmTBI induced the greatest impairments in males on cognitive and motor tasks whereas in females the most significant detriments were on pain-related tasks. Both caffeine and RmTBI increased spine density in the Cg3 (medial prefrontal cortex [mPFC]), AID (orbitofrontal cortex [OFC]), and nucleus accumbens (NAc), which is proposed to reflect an impairment in the normal pruning processes. Overall, despite caffeine's neuroprotective abilities among other age groups, this study offers concerning results regarding the detrimental effects of caffeine and RmTBI, in isolation, and especially in combination, in this susceptible population.

中文翻译：

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在发育过程中摄入咖啡因会改变年轻成年大鼠的脊柱密度和重复性轻度创伤性脑损伤的恢复。

咖啡因是世界上最常用的精神兴奋剂，其消费量在青少年和年轻人中尤为普遍，因为该群体中有超过 75% 的人每天摄入咖啡因。同样，青少年和青年年龄组的外伤性脑损伤 (TBI) 发生率最高。鉴于咖啡因摄入和轻度 TBI (mTBI) 在青少年晚期/年轻成人年龄组中更为普遍，并且对这一发育时期树突棘形态的变化知之甚少，本研究试图检查咖啡因摄入对晚期青少年的影响。从重复性 mTBI (RmTBI) 中恢复的青春期/成年早期。该研究特别关注神经元树突形态的变化，因为突触变化可能是长期行为结果的基础。结果表明，在年轻的成年期，咖啡因摄入对男性和女性的 RmTBI 结果有不同的影响，其中咖啡因和 RmTBI 的影响在男性中通常是相加的，而在女性中同样有害，但很少相加。一般来说，咖啡因和 RmTBI 对男性在认知和运动任务上造成的损害最大，而在女性中，最显着的损害发生在与疼痛相关的任务上。咖啡因和 RmTBI 都增加了 Cg3（内侧前额叶皮层 [mPFC]）、AID（眶额皮层 [OFC]）和伏隔核（NAc）的脊柱密度，这被认为是为了反映正常修剪过程中的损伤。总体而言，尽管咖啡因在其他年龄组中具有神经保护能力，