Venkatraman Anand, Edlow Brian L, Immordino-Yang Mary Helen
Department of Neurology, University of Alabama at Birmingham, Birmingham, AL USA.
Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA USA.
Front Neuroanat. 2017 Mar 9;11:15. doi: 10.3389/fnana.2017.00015. eCollection 2017.
Emotions depend upon the integrated activity of neural networks that modulate arousal, autonomic function, motor control, and somatosensation. Brainstem nodes play critical roles in each of these networks, but prior studies of the neuroanatomic basis of emotion, particularly in the human neuropsychological literature, have mostly focused on the contributions of cortical rather than subcortical structures. Given the size and complexity of brainstem circuits, elucidating their structural and functional properties involves technical challenges. However, recent advances in neuroimaging have begun to accelerate research into the brainstem's role in emotion. In this review, we provide a conceptual framework for neuroscience, psychology and behavioral science researchers to study brainstem involvement in human emotions. The "emotional brainstem" is comprised of three major networks - Ascending, Descending and Modulatory. The Ascending network is composed chiefly of the spinothalamic tracts and their projections to brainstem nuclei, which transmit sensory information from the body to rostral structures. The Descending motor network is subdivided into medial projections from the reticular formation that modulate the gain of inputs impacting emotional salience, and lateral projections from the periaqueductal gray, hypothalamus and amygdala that activate characteristic emotional behaviors. Finally, the brainstem is home to a group of modulatory neurotransmitter pathways, such as those arising from the raphe nuclei (serotonergic), ventral tegmental area (dopaminergic) and locus coeruleus (noradrenergic), which form a Modulatory network that coordinates interactions between the Ascending and Descending networks. Integration of signaling within these three networks occurs at all levels of the brainstem, with progressively more complex forms of integration occurring in the hypothalamus and thalamus. These intermediary structures, in turn, provide input for the most complex integrations, which occur in the frontal, insular, cingulate and other regions of the cerebral cortex. Phylogenetically older brainstem networks inform the functioning of evolutionarily newer rostral regions, which in turn regulate and modulate the older structures. Via these bidirectional interactions, the human brainstem contributes to the evaluation of sensory information and triggers fixed-action pattern responses that together constitute the finely differentiated spectrum of possible emotions.
情绪取决于神经网络的整合活动，这些神经网络调节唤醒、自主功能、运动控制和躯体感觉。脑干节点在这些网络中均发挥着关键作用，但先前关于情绪神经解剖学基础的研究，尤其是在人类神经心理学文献中，大多聚焦于皮质结构而非皮质下结构的贡献。鉴于脑干回路的规模和复杂性，阐明其结构和功能特性面临技术挑战。然而，神经影像学的最新进展已开始加速对脑干在情绪中作用的研究。在本综述中，我们为神经科学、心理学和行为科学研究人员提供了一个概念框架，以研究脑干在人类情绪中的参与情况。“情绪脑干”由三个主要网络组成——上行网络、下行网络和调节网络。上行网络主要由脊髓丘脑束及其向脑干核的投射组成，其将来自身体的感觉信息传递至脑前部结构。下行运动网络可细分为来自网状结构的内侧投射，其调节影响情绪显著性的输入增益，以及来自导水管周围灰质、下丘脑和杏仁核的外侧投射，其激活特征性情绪行为。最后，脑干是一组调节性神经递质通路的所在地，例如那些源自中缝核（5-羟色胺能）、腹侧被盖区（多巴胺能）和蓝斑（去甲肾上腺素能）的通路，它们形成一个调节网络，协调上行网络和下行网络之间的相互作用。这三个网络内的信号整合发生在脑干的各个层面，在下丘脑和丘脑发生的整合形式逐渐更为复杂。这些中间结构进而为在额叶、岛叶、扣带回和大脑皮质其他区域发生的最复杂整合提供输入。从系统发育角度来看，较古老的脑干网络为进化上较新的脑前部区域的功能提供信息，而这些脑前部区域又反过来调节和调制较古老的结构。通过这些双向相互作用，人类脑干有助于对感觉信息进行评估，并触发固定动作模式反应，这些反应共同构成了可能情绪的精细分化谱。
