VA Boston Healthcare System, West Roxbury, MA, USA; Department of Psychiatry, Harvard Medical School, Boston, MA, USA.
Brain Res Bull. 2022 Jul;185:129-139. doi: 10.1016/j.brainresbull.2022.05.005. Epub 2022 May 11.
The precise interplay between large-scale functional neural systems throughout the brain is essential for performance of cognitive processes. In this review we focus on the default mode network (DMN), one such functional network that is active during periods of quiet wakefulness and believed to be involved in introspection and planning. Abnormalities in DMN functional connectivity and activation appear across many neuropsychiatric disorders, including schizophrenia. Recent evidence suggests subcortical regions including the basal forebrain are functionally and structurally important for regulation of DMN activity. Within the basal forebrain, subregions like the ventral pallidum may influence DMN activity and the nucleus basalis of Meynert can inhibit switching between brain networks. Interactions between DMN and other functional networks including the medial frontoparietal network (default), lateral frontoparietal network (control), midcingulo-insular network (salience), and dorsal frontoparietal network (attention) are also discussed in the context of neuropsychiatric disorders. Several subtypes of basal forebrain neurons have been identified including basal forebrain parvalbumin-containing or somatostatin-containing neurons which can regulate cortical gamma band oscillations and DMN-like behaviors, and basal forebrain cholinergic neurons which might gate access to sensory information during reinforcement learning. In this review, we explore this evidence, discuss the clinical implications on neuropsychiatric disorders, and compare neuroanatomy in the human vs rodent DMN. Finally, we address technological advancements which could help provide a more complete understanding of modulation of DMN function and describe newly identified BF therapeutic targets that could potentially help restore DMN-associated functional deficits in patients with a variety of neuropsychiatric disorders.
大脑中大规模功能神经系统的精确相互作用对于认知过程的表现至关重要。在这篇综述中，我们重点关注默认模式网络（DMN），这是一种在安静觉醒期间活跃的功能网络，被认为与内省和计划有关。许多神经精神障碍，包括精神分裂症，都存在 DMN 功能连接和激活的异常。最近的证据表明，包括基底前脑在内的皮质下区域对于 DMN 活动的调节具有功能和结构上的重要性。在基底前脑内，腹侧苍白球等亚区可能会影响 DMN 活动，并且 Meynert 基底核可以抑制大脑网络之间的切换。DMN 与其他功能网络（包括内侧额顶网络（默认）、外侧额顶网络（控制）、中扣带回岛网络（突显）和背侧额顶网络（注意））之间的相互作用也在神经精神障碍的背景下进行了讨论。已经确定了几种基底前脑神经元亚型，包括含有基底前脑 parvalbumin 或 somatostatin 的神经元，它们可以调节皮质γ带振荡和类似于 DMN 的行为，以及含有基底前脑胆碱能神经元，它们可能在强化学习期间门控对感觉信息的访问。在这篇综述中，我们探讨了这方面的证据，讨论了其对神经精神障碍的临床意义，并比较了人类和啮齿动物 DMN 的神经解剖结构。最后，我们讨论了可以帮助提供对 DMN 功能调节的更全面理解的技术进步，并描述了新确定的 BF 治疗靶标，这些靶标可能有助于恢复各种神经精神障碍患者与 DMN 相关的功能缺陷。
