Leva Tobias M, Whitmire Clarissa J
Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany.
Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany.
Front Neurosci. 2023 Oct 13;17:1210949. doi: 10.3389/fnins.2023.1210949. eCollection 2023.
The thalamus acts as an interface between the periphery and the cortex, with nearly every sensory modality processing information in the thalamocortical circuit. Despite well-established thalamic nuclei for visual, auditory, and tactile modalities, the key thalamic nuclei responsible for innocuous thermosensation remains under debate. Thermosensory information is first transduced by thermoreceptors located in the skin and then processed in the spinal cord. Temperature information is then transmitted to the brain through multiple spinal projection pathways including the spinothalamic tract and the spinoparabrachial tract. While there are fundamental studies of thermal transduction via thermosensitive channels in primary sensory afferents, thermal representation in the spinal projection neurons, and encoding of temperature in the primary cortical targets, comparatively little is known about the intermediate stage of processing in the thalamus. Multiple thalamic nuclei have been implicated in thermal encoding, each with a corresponding cortical target, but without a consensus on the role of each pathway. Here, we review a combination of anatomy, physiology, and behavioral studies across multiple animal models to characterize the thalamic representation of temperature in two proposed thermosensory information streams.
丘脑充当外周与皮层之间的接口，几乎每种感觉模态都在丘脑皮层回路中处理信息。尽管视觉、听觉和触觉模态的丘脑核已明确，但负责无害温度感觉的关键丘脑核仍存在争议。温度感觉信息首先由位于皮肤中的温度感受器转导，然后在脊髓中进行处理。随后，温度信息通过包括脊髓丘脑束和脊髓臂旁束在内的多条脊髓投射通路传输至大脑。虽然已有关于初级感觉传入神经中通过热敏通道进行热转导、脊髓投射神经元中的热表征以及初级皮层靶区中温度编码的基础研究，但对于丘脑处理的中间阶段却知之甚少。多个丘脑核参与了热编码，每个丘脑核都有相应的皮层靶区，但对于每条通路的作用尚未达成共识。在此，我们综述了多种动物模型的解剖学、生理学和行为学研究的结合，以表征在两条提议的温度感觉信息流中温度的丘脑表征。
