Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden.
Department of Integrative Medical Biology, Umeå University, Umeå, Sweden.
Transl Psychiatry. 2023 Jan 31;13(1):28. doi: 10.1038/s41398-022-02270-9.
Age-related dopamine reductions have been suggested to contribute to maladaptive working memory (WM) function in older ages. One promising intervention approach is to increase physical activity, as this has been associated with plasticity of the striatal dopamine system and WM improvements, however with individual differences in efficacy. The present work focused on the impact of individual differences in white-matter lesion burden upon dopamine D2-like receptor (DRD2) availability and WM changes in response to a 6 months physical activity intervention. While the intervention altered striatal DRD2 availability and WM performance in individuals with no or only mild lesions (p < 0.05), no such effects were found in individuals with moderate-to-severe lesion severity (p > 0.05). Follow-up analyses revealed a similar pattern for processing speed, but not for episodic memory performance. Linear analyses further revealed that lesion volume (ml) at baseline was associated with reduced DRD2 availability (r = -0.41, p < 0.05), and level of DRD2 change (r = 0.40, p < 0.05). Taken together, this study underlines the necessity to consider cerebrovascular health in interventions with neurocognitive targets. Future work should assess whether these findings extend beyond measures of DRD2 availability and WM.
年龄相关的多巴胺减少被认为是导致老年人适应不良的工作记忆（WM）功能的原因之一。一种有前途的干预方法是增加身体活动，因为这与纹状体多巴胺系统的可塑性和 WM 改善有关，但效果因人而异。本研究重点关注个体间的差异对脑白质病变负荷对多巴胺 D2 样受体（DRD2）可用性和 WM 变化的影响，以及对 6 个月身体活动干预的反应。虽然该干预改变了无或仅有轻度病变个体的纹状体 DRD2 可用性和 WM 表现（p < 0.05），但在中重度病变严重程度个体中未发现这种影响（p > 0.05）。随访分析显示，处理速度也呈现出类似的模式，但情节记忆表现则不然。线性分析进一步表明，基线时的病变体积（ml）与 DRD2 可用性降低（r = -0.41，p < 0.05）和 DRD2 变化水平（r = 0.40，p < 0.05）相关。综上所述，这项研究强调了在针对神经认知目标的干预中考虑脑血管健康的必要性。未来的研究应评估这些发现是否超出了 DRD2 可用性和 WM 的测量范围。
