Miller Derek M, DeMayo William M, Bourdages George H, Wittman Samuel R, Yates Bill J, McCall Andrew A
Department of Otolaryngology, Eye and Ear Institute, University of Pittsburgh, 203 Lothrop Street, Suite 500, Pittsburgh, PA, 15213, USA.
Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA.
Exp Brain Res. 2017 Apr;235(4):1195-1207. doi: 10.1007/s00221-017-4875-x. Epub 2017 Feb 10.
The integration of inputs from vestibular and proprioceptive sensors within the central nervous system is critical to postural regulation. We recently demonstrated in both decerebrate and conscious cats that labyrinthine and hindlimb inputs converge onto vestibular nucleus neurons. The pontomedullary reticular formation (pmRF) also plays a key role in postural control, and additionally participates in regulating locomotion. Thus, we hypothesized that like vestibular nucleus neurons, pmRF neurons integrate inputs from the limb and labyrinth. To test this hypothesis, we recorded the responses of pmRF neurons to passive ramp-and-hold movements of the hindlimb and to whole-body tilts, in both decerebrate and conscious felines. We found that pmRF neuronal activity was modulated by hindlimb movement in the rostral-caudal plane. Most neurons in both decerebrate (83% of units) and conscious (61% of units) animals encoded both flexion and extension movements of the hindlimb. In addition, hindlimb somatosensory inputs converged with vestibular inputs onto pmRF neurons in both preparations. Pontomedullary reticular formation neurons receiving convergent vestibular and limb inputs likely participate in balance control by governing reticulospinal outflow.
中枢神经系统内前庭和本体感觉传感器输入的整合对于姿势调节至关重要。我们最近在去大脑和清醒的猫身上均证明，迷路和后肢输入会聚到前庭核神经元上。脑桥延髓网状结构（pmRF）在姿势控制中也起关键作用，并且还参与调节运动。因此，我们假设，与前庭核神经元一样，pmRF神经元整合来自肢体和迷路的输入。为了验证这一假设，我们记录了去大脑和清醒猫中pmRF神经元对后肢被动斜坡-保持运动以及全身倾斜的反应。我们发现，pmRF神经元活动在头-尾平面上受后肢运动调节。在去大脑（83%的单位）和清醒（61%的单位）动物中，大多数神经元都编码后肢的屈伸运动。此外，在两种准备状态下，后肢体感输入与前庭输入都会聚到pmRF神经元上。接受前庭和肢体输入会聚的脑桥延髓网状结构神经元可能通过控制网状脊髓传出参与平衡控制。
