Iwakiri H, Oka T, Takakusaki K, Mori S
National Institute for Physiological Sciences, Okazaki, Japan.
Neurosci Res. 1995 Aug;23(1):47-53.
In acute decerebrate cats, medial pontine reticular formation (mPRF) and the mesencephalic locomotor region (MLR) were stimulated and their stimulus effects upon 250 medullary reticulospinal neurons (RSNs) were studied. One hundred and twenty-six RSNs were mono- and disynaptically activated. From the response patterns of the RSNs, they were divided into the mPRF-activated RSNs (n = 67) and the MLR-activated RSNs (n = 59). The former group of RSNs was located in the nucleus reticularis gigantocellularis (NRGc), while the latter group of RSNs was distributed in both the NRGc and the nucleus reticularis magnocellularis (NRMc). The activity of MLR-excited 12 RSNs was suppressed with the preceding mPRF stimulation. These RSNs were mainly located in the NRMc. Most mPRF-excited RSNs increased their discharge rates during mPRF-evoked suppression of postural muscle tone, and most MLR-excited RSNs increased their discharge rates during MLR-evoked locomotion. With mPRF stimulation, MLR-evoked locomotion was suppressed with cessation of MLR-excited RSNs activity. These results suggest that mPRF stimulation suppresses the activity of the locomotor rhythm generating system at the levels of not only the spinal cord but also the medullary output cells.
在急性去大脑猫中，刺激脑桥内侧网状结构（mPRF）和中脑运动区（MLR），并研究它们对250个延髓网状脊髓神经元（RSNs）的刺激效应。126个RSNs被单突触和双突触激活。根据RSNs的反应模式，将它们分为mPRF激活的RSNs（n = 67）和MLR激活的RSNs（n = 59）。前一组RSNs位于巨细胞网状核（NRGc），而后一组RSNs分布在NRGc和大细胞网状核（NRMc）。在mPRF刺激之前，MLR兴奋的12个RSNs的活动受到抑制。这些RSNs主要位于NRMc。大多数mPRF兴奋的RSNs在mPRF诱发的姿势肌张力抑制期间放电率增加，大多数MLR兴奋的RSNs在MLR诱发的运动期间放电率增加。通过mPRF刺激，随着MLR兴奋的RSNs活动停止，MLR诱发的运动受到抑制。这些结果表明，mPRF刺激不仅在脊髓水平，而且在延髓输出细胞水平抑制运动节律产生系统的活动。
