Ascending Pathways for the Periaqueductal Gray

描述(由申请人提供)：这项提案的广泛、长期目标是阐明决定情绪和情感的神经系统的组织。这项拟议研究的主要目标是在猴子身上确定中脑导水管周围灰质(PAG)可能影响皮质功能的轴突通路。PAG作为产生情绪表达的关键成分，PAG的不同细分协调了对不同类型压力的不同情绪反应。PAG广泛投射到丘脑中线/层内核(ILN)，这是PAG影响皮质功能的一种可能途径。在大鼠中，个体ILN投射到大脑皮质的限定区域，这些区域对应于灵长类眼眶和内侧前额叶皮质(OMPFC)，这是一个被认为参与情绪处理最高水平的皮质区域。虽然这些通向大脑皮层的通路在老鼠身上最为人所知，但OMPFC在猴子身上要发达得多，也更为人所知。特别是，灵长类OMPFC可以被划分为不同的功能网络，这些网络被假设为服从情绪的不同成分。假设来自PAG各亚区的上升通路将与这两个网络进行不同的相互作用，反映了它们在应激情绪反应中的不同作用。清楚地了解这一途径在灵长类动物中是如何联系在一起的，可能会提供对精神疾病的神经基础的洞察，如严重的抑郁症和焦虑症，这些疾病的特征是对压力做出不适应的情绪反应。

DESCRIPTION (provided by applicant): The broad, long-term goal of this proposal is to elucidate the organization of neural systems that determine mood and affect. The primary objective of the proposed research is to define in monkeys the axonal pathways by which the midbrain periaqueductal gray (PAG) may influence cortical function. The PAG as a critical component in generating emotional expression, and distinct subdivisions of the PAG coordinate distinct emotional reactions to different types of stress. The PAG projects extensively to the midline/intralaminar thalamic nuclei (ILN), which represents one likely pathway through which the PAG may influence cortical function. In rats, individual ILN project to circumscribed areas of the cerebral cortex that correspond to the primate orbital and medial prefrontal cortex (OMPFC), a cortical area thought to be involved in the highest levels of emotional processing. Although these pathways to the cerebral cortex are best known in rats, the OMPFC is much more developed and better known in monkeys. In particular, the primate OMPFC can be divided into distinct functional networks that are hypothesized to subserve different components of emotion. It is hypothesized that the ascending pathways from subdivisions of the PAG will interact differentially with the two networks, reflecting their differential role in emotional reactions to stress. A clear understanding of how this pathway is linked in primates may provide insight into the neural basis of psychiatric illnesses such as major depression and anxiety disorders, which are characterized by maladaptive emotional responses to stress.