Department of Neuroscience and Pharmacology, Copenhagen University – Panum Institute – 12.3, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
J Physiol. 2011 May 15;589(Pt 10):2543-58. doi: 10.1113/jphysiol.2011.207225. Epub 2011 Mar 28.
The brainstem contains rhythm and pattern forming circuits, which drive cranial and spinal motor pools to produce respiratory and other motor patterns. Here we used calcium imaging combined with nerve recordings in newborn mice to reveal spontaneous population activity in the ventral brainstem and in the facial nucleus. In Fluo-8AM loaded brainstem-spinal cord preparations, respiratory activity on cervical nerves was synchronized with calcium signals at the ventrolateral brainstem surface. Individual ventrolateral neurons at the level of the parafacial respiratory group showed perfect or partial synchrony with respiratory nerve bursts. In brainstem-spinal cord preparations, cut at the level of the mid-facial nucleus, calcium signals were recorded in the dorsal, lateral and medial facial subnuclei during respiratory activity. Strong activity initiated in the dorsal subnucleus, followed by activity in lateral and medial subnuclei. Whole-cell recordings from facial motoneurons showed weak respiratory drives, and electrical field potential recordings confirmed respiratory drive to particularly the dorsal and lateral subnuclei. Putative facial premotoneurons showed respiratory-related calcium signals, and were predominantly located dorsomedial to the facial nucleus. A novel motor activity on facial, cervical and thoracic nerves was synchronized with calcium signals at the ventromedial brainstem extending from the level of the facial nucleus to the medulla–spinal cord border. Cervical dorsal root stimulation induced similar ventromedial activity. The medial facial subnucleus showed calcium signals synchronized with this novel motor activity on cervical nerves, and cervical dorsal root stimulation induced similar medial facial subnucleus activity. In conclusion, the dorsal and lateral facial subnuclei are strongly respiratory-modulated, and the brainstem contains a novel pattern forming circuit that drives the medial facial subnucleus and cervical motor pools.
脑干包含节律和模式形成回路，这些回路驱动颅神经和脊神经运动池产生呼吸和其他运动模式。在这里，我们使用钙成像结合新生小鼠的神经记录，揭示了腹侧脑干和面神经核中的自发群体活动。在 Fluo-8AM 加载的脑干-脊髓标本中，颈部神经的呼吸活动与腹侧脑干表面的钙信号同步。面神经根水平的个别腹外侧神经元与呼吸神经爆发显示出完美或部分同步。在脑干-脊髓标本中，在面神经核中部切断后，在呼吸活动期间，在背侧、外侧和内侧面神经亚核中记录钙信号。强烈的活动始于背侧亚核，随后是外侧和内侧亚核的活动。面神经运动神经元的全细胞记录显示呼吸驱动较弱，电场电位记录证实呼吸驱动特别是对背侧和外侧亚核。假定的面前运动神经元显示与呼吸相关的钙信号，并且主要位于面神经核的背内侧。在从面神经核到延髓-脊髓交界的腹侧脑干上，面神经、颈部和胸部神经上出现了一种与钙信号同步的新型运动活动。颈部背根刺激诱导类似的腹侧活动。钙信号与颈部神经上的这种新型运动活动同步的内侧面神经亚核，并且颈部背根刺激诱导类似的内侧面神经亚核活动。总之，背侧和外侧面神经亚核强烈受呼吸调节，并且脑干包含一个驱动内侧面神经亚核和颈部运动池的新型模式形成回路。
