ACTIVITY IN THE MESENCEPHALIC LOCOMOTOR REGION DURING LOCOMOTION
ACTIVITY IN THE MESENCEPHALIC LOCOMOTOR REGION DURING LOCOMOTION
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DOI：
10.1016/0014-4886(83)90084-5
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发表时间：
1983-01-01
影响因子：
5.3
通讯作者：
FITZGERALD, JA
中科院分区：
文献类型：
--
作者：
GARCIARILL, E;SKINNER, RD;FITZGERALD, JA
用细胞外方法记录了猫在跑台上自发运动时中脑运动区(MLR)单个神经元的活动。虽然在猫的前丘-乳房后脑干横断后，需要刺激MLR才能在跑步机上诱导运动，但在丘前-乳房前横断后，可能会发生自发运动。肌电图仪记录各肢体屈伸肌的活动情况。近50%的MLR神经元在运动过程中表现出节律性的放电模式。在.apprx中。在这些细胞中的1/2，通过使用棘波触发的平均，单位放电模式可以与一块或多块肌肉的肌电活动相关联。单个MLR神经元与单侧肢体肌电活动相关，其余与双侧或全部4侧肢体肌电活动相关。被动运动或肢体停顿(S)并不能消除这些神经元的节律性。体感刺激似乎不影响MLR神经元的放电模式。相关前肢肌肉的平均肌电显示峰后平均潜伏期为7.1ms。这些测量结果与有关MLR对网状脊髓神经元的投射延迟1至1.5毫秒，以及与运动过程中的肌电相关的网状脊髓活动延迟5至6毫秒的报道一致。显然，MLR神经元在运动过程中是节律性的，MLR神经元的活动可与1条或多条肢体的EMG活动相关，MLR神经元的节律性可能不依赖于时相感觉输入，MLR的下游影响可能至少部分通过网状脊髓神经元传递。
The activity of single neurons in the mesencephalic locomotor region (MLR) was recorded extracellularly in cats during spontaneous locomotion on a treadmill. Although stimulation of the MLR is required to induce locomotion on a treadmill after a precollicular-postmamillary brain stem transection in the cat, spontaneous locomotion may occur after a precollicular-premamillary transection. The activity of flexor and extensor muscles of each limb also was recorded by EMG [electromyogram]. Nearly 50% of the MLR neurons exhibited rhythmic firing patterns during locomotion. In .apprx. 1/2 of those cells, unit firing patterns could be correlated with the EMG activity in 1 or more muscles by using spike-triggered averaging. Single MLR neurons correlated with EMG activity in a single limb, and others were related to the EMG from muscles in 2 limbs or in all 4 limbs. Passive movement or stoppage of the limb(s) did not abolish rhythmicity in theses neurons. Somatosensory stimulation did not appear to affect the firing patterns of MLR neurons. Averaged EMG of correlated forelimb muscles revealed a postspike mean latency of 7.1 ms. These measurements agreed well with reports of a 1- to 1.5-ms delay in MLR projections to reticulospinal neurons and a 5- to 6-ms delay (postspike) in reticulospinal activity correlated to EMG during locomotion. Apparently, MLR neurons are rhythmically active during locomotion, the activity of MLR neurons can be correlated with that of EMG in 1 or more limbs, rhythmicity in MLR neurons may be independent of phasic sensory input, and the downstream influence of the MLR may be relayed, at least in part, via reticulospinal neurons.