Mutable and immutable features of paw-shake responses after hindlimb deafferentation in the cat.
Mutable and immutable features of paw-shake responses after hindlimb deafferentation in the cat.
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猫后肢传入神经阻滞后爪子震动反应的可变和不可变特征。
DOI：
10.1152/jn.1989.62.1.162
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发表时间：
1989
影响因子：
2.5
通讯作者：
Smith,JL
中科院分区：
文献类型：
--
作者：
Koshland,GF;Smith,JL
1. 在慢性脊柱猫 (n = 5) 的单侧传入神经阻滞 (L3-S1) 前后评估后肢爪子抖动反应，1 年前在 T12 水平进行脊柱化。通过手术将选定的踝屈肌 [胫骨前肌 (TA)] 和伸肌 [腓肠肌外侧肌 (LG)] 和膝伸肌 [股外侧肌 (VL)] 肌肉植入慢性肌电图 (EMG) 电极，以确定由运动依赖性反馈调节的周期特征和肌肉协同作用的可变特征，而不是集中编程且不受肢体传入调节的不变特征。 2. 在广泛性传入神经缺失的后肢中很难引起颤抖反应；尤其是在传入神经阻滞后的最初恢复几周内，情况尤其如此。然而，到第一个月末，五只猫中的四只通常会引发 1 或 2 个周期的短暂反应，而到第二个月末，五只猫中的三只通常会引发 3-7 个周期的反应。最初，传入耳聋肢体的反应是由施加到大腿背外侧的刺激引起的，大腿背外侧是一块由完整的 S2 传入神经支配的椭圆形皮肤。然而，在 4 个月的恢复期内，大部分去神经支配的皮肤的感受野扩大了，施加于膝盖和小腿外侧的刺激也会引起反应，但通常不会刺激爪子。 3. 除了每次反应的平均周期较少（5 比 10 周期）外，在传入神经缺失的后肢中引起的爪子抖动的特点是周期周期长于平均周期（124 比 98 毫秒），但不同反应的平均周期周期差异很大，范围从 99 到 239 毫秒。在传入阻滞之前，连续周期的时间组织是刻板的；在整个响应过程中，循环周期呈线性增加。然而，传入阻滞后，周期周期和周期数之间不存在系统关系，并且大约 14% 大于或等于 3 个周期的记录以 EMG 突发的节律序列为特征。 4. 在脚踝处，LG 爆发持续时间不会因传入阻滞而改变，但 TA 起始时间和爆发持续时间会受到影响。在传入阻滞之前，TA 起始相对于周期开始是不变的，突发持续时间随周期周期线性增加。然而，传入阻滞后，TA 开始延迟，并且延迟随周期时间线性增加。因此，TA 突发持续时间很短，并且与周期周期无关。（摘要截断为 400 字）
1. Hindlimb paw-shake responses were assessed before and after unilateral deafferentation (L3-S1) in chronic-spinal cats (n = 5), spinalized at the T12 level 1 yr earlier. Selected ankle flexor [tibialis anterior (TA)] and extensor [lateral gastrocnemius (LG)] and knee extensor [vastus lateralis (VL)] muscles were surgically implanted with chronic electromyographic (EMG) electrodes to determine mutable features of cycle characteristics and muscle synergies that are modulated by motion-dependent feedback as opposed to immutable features that are centrally programmed and not modulated by limb afference. 2. Paw-shake responses were difficult to elicit in the extensively deafferented hindlimb; this was true particularly during the first recovery weeks after deafferentation. By the end of the first month, however, brief responses of 1 or 2 cycles were commonly elicited in four of five cats, and responses of 3-7 cycles were common by the end of the second month in three of five cats. Initially, responses in the deafferented limb were elicited by stimuli applied to the dorsolateral thigh, an oval patch of skin innervated by intact S2 afferents. Over the 4-mo recovery period, however, the receptive field of the largely denervated skin expanded, and responses were also elicited by stimuli applied to the lateral aspect of the knee and shank, but usually not the paw. 3. In addition to fewer average cycles per response (5 vs. 10 cycles), paw shaking evoked in the deafferented hindlimb was characterized by longer-than-average cycle periods (124 vs. 98 ms), but the average cycle period varied widely among responses, ranging from 99 to 239 ms. Before deafferentation, the temporal organization of consecutive cycles was stereotypic; cycle periods increased linearly throughout a response. After deafferentation, however, there was no systematic relationship between cycle period and cycle number, and approximately 14% of the records with greater than or equal to 3 cycles were characterized by arhythmical sequences of EMG bursts. 4. At the ankle, LG burst duration was not altered by deafferentation, but TA onset and burst duration were affected. Before deafferentation, TA onset was invariant with respect to the beginning of the cycle, and burst duration increased linearly with cycle period. After deafferentation, however, TA onset was delayed, and the delay increased linearly with cycle period. Consequently, the TA burst duration was brief and unrelated to cycle period.(ABSTRACT TRUNCATED AT 400 WORDS)