Department of Chiropractic, Université du Québec à Trois-Rivières, 3351 Boul. Des Forges, C.P. 500, Trois-Rivières, QC, G9A 5H7, Canada; CogNAC Research Group, Université du Québec à Trois-Rivières, 3351 Boul. Des Forges, C.P. 500, Trois-Rivières, QC, G9A 5H7, Canada; Department of Anatomy, Université du Québec à Trois-Rivières, 3351 Boul. Des Forges, C.P. 500, Trois-Rivières, QC, G9A 5H7, Canada.
Department of Chiropractic, Université du Québec à Trois-Rivières, 3351 Boul. Des Forges, C.P. 500, Trois-Rivières, QC, G9A 5H7, Canada; CogNAC Research Group, Université du Québec à Trois-Rivières, 3351 Boul. Des Forges, C.P. 500, Trois-Rivières, QC, G9A 5H7, Canada.
Neurosci Res. 2019 Dec;149:22-28. doi: 10.1016/j.neures.2019.01.008. Epub 2019 Jan 31.
Cerebral blood flow (CBF) is essential for neuronal metabolic functions. CBF is partly regulated by cholinergic projections from the nucleus basalis of Meynert (NBM) during cortical processing of sensory information. During pain-related processing, however, this mechanism may be altered by large fluctuations in systemic mean arterial pressure (MAP). The objective of this study was to investigate the contribution of NBM to CBF responses evoked by nociceptive electrical stimuli and how it may be affected by systemic MAP. CBF was recorded in isoflurane-anesthetized rats (n = 8) using laser speckle contrast imaging, in two conditions (intact vs left NBM lesion). Electrical stimulation was applied to the sciatic nerve. Sciatic stimulation produced intensity dependent increases in MAP (p < 0.001) that were almost identical between conditions (intact vs left NBM lesion; p = 0.96). In both conditions, sciatic stimulation produced intensity dependent CBF increases (p < 0.001). After NBM lesion, CBF responses were decreased in the left somatosensory cortex ipsilateral to NBM lesion (p = 0.02) but not in the right somatosensory cortex (p = 0.46). These results indicate that NBM contributes to CBF responses to nociceptive stimulation in the ipsilateral, but not contralateral somatosensory cortex and that CBF response attenuation by NBM lesion is not compensated passively by systemic MAP changes. This highlights the importance of NBM's integrity for pain-related hemodynamic responses in the somatosensory cortex.
大脑血流 (CBF) 对神经元代谢功能至关重要。在皮质处理感觉信息期间，CBF 部分受到来自梅内特基底核 (NBM) 的胆碱能投射的调节。然而，在与疼痛相关的处理过程中，这种机制可能会受到全身平均动脉压 (MAP) 大幅波动的影响。本研究的目的是研究 NBM 对伤害性电刺激引起的 CBF 反应的贡献，以及它如何受到全身 MAP 的影响。在异氟烷麻醉的大鼠中（n=8）使用激光散斑对比成像记录 CBF，在两种情况下（完整 vs 左侧 NBM 损伤）。电刺激施加于坐骨神经。坐骨刺激引起 MAP 的强度依赖性增加（p<0.001），两种情况下几乎相同（完整 vs 左侧 NBM 损伤；p=0.96）。在两种情况下，坐骨刺激均引起 CBF 的强度依赖性增加（p<0.001）。在 NBM 损伤后，左侧体感皮层同侧的 CBF 反应减少（p=0.02），但右侧体感皮层无变化（p=0.46）。这些结果表明，NBM 有助于对伤害性刺激的同侧体感皮层 CBF 反应，但对对侧体感皮层无影响，并且 NBM 损伤引起的 CBF 反应减弱不会被全身 MAP 变化被动补偿。这突出了 NBM 完整性对于体感皮层疼痛相关血流动力学反应的重要性。
