研究人员出乎意料地发现，通过初级运动皮层（M1）第6层-背内侧丘脑的通路，从M1到伏隔核奖励回路的连接，特异性抑制了神经病理性疼痛的负面情绪和相关应对行为。相比之下，第5层的M1神经元则与未定带和导水管周围灰质的特定细胞群相连，以抑制感觉过敏而不改变疼痛影响。因此，M1采用不同的、特定层的途径来调整神经病理性疼痛的感觉和厌恶情绪成分，这可以被利用来达到缓解疼痛的目的。
据介绍，M1参与自愿运动的控制，并被广泛地映射到这个能力中。尽管M1与疼痛的调控有关，但其背后的回路和因果关系仍然难以捉摸。
附：英文原文
Title: Layer-specific pain relief pathways originating from primary motor cortex
Author: Zheng Gan, Vijayan Gangadharan, Sheng Liu, Christoph Krber, Linette Liqi Tan, Han Li, Manfred Josef Oswald, Juhyun Kang, Jesus Martin-Cortecero, Deepitha Mnnich, Alexander Groh, Thomas Kuner, Sebastian Wieland, Rohini Kuner
Issue&Volume: 2022-12-23
Abstract: The primary motor cortex (M1) is involved in the control of voluntary movements and is extensively mapped in this capacity. Although the M1 is implicated in modulation of pain, the underlying circuitry and causal underpinnings remain elusive. We unexpectedly unraveled a connection from the M1 to the nucleus accumbens reward circuitry through a M1 layer 6-mediodorsal thalamus pathway, which specifically suppresses negative emotional valence and associated coping behaviors in neuropathic pain. By contrast, layer 5 M1 neurons connect with specific cell populations in zona incerta and periaqueductal gray to suppress sensory hypersensitivity without altering pain affect. Thus, the M1 employs distinct, layer-specific pathways to attune sensory and aversive-emotional components of neuropathic pain, which can be exploited for purposes of pain relief.
DOI: add4391
Source: https://www.science.org/doi/10.1126/science.add4391