Calişkan S, Tan S, Tan U
Atatürk University, Medical Faculty, Institute of Physiology, Erzurum, Turkey.
Int J Neurosci. 1991 Jan-Feb;56(1-4):93-106. doi: 10.3109/00207459108985408.
Hoffmann (H) reflexes from foreleg flexor nerves were studied in cats. The right and left flexor nerves were stimulated and H reflexes were recorded from the same nerves. Paw preference was assessed by a food reaching test. Stimulation of the right median nerve elicited mono- and polysynaptic reflexes from the left ulnar nerve (crossed flexor nerve). Picrotoxin depressed, and strychnine increased H reflexes from both sides without affecting the spinal motor asymmetry. H reflexes were found to be larger on the left than the right side in right-preferent cats and vice versa in left-preferent cats. The right H-reflex recovery curve was higher than left in right-preferent cats. The inhibitory period of the recovery cycle disappeared after picrotoxin and changed to facilitation for the nonpreferred side. Strychinine caused bilateral, nearly-synchronous motoneuronal discharges from the right and left flexor nerves; the discharges originating from the left side preceded those from the right side in a right-preferent cat. These results indicate that spinal motor activity predominates on the nonpreferred side, which would be a prerequisite for postural adjustments during paw use in cats. This asymmetric motor organization in the forelegs of cats having quadrpedal locomotion seems to be similar to asymmetric motor organization in legs in humans.
在猫身上研究了来自前肢屈肌神经的霍夫曼（H）反射。刺激右侧和左侧屈肌神经，并从相同神经记录H反射。通过食物获取测试评估爪偏好。刺激右侧正中神经会引发来自左侧尺神经（交叉屈肌神经）的单突触和多突触反射。印防己毒素会抑制，而士的宁会增强两侧的H反射，且不影响脊髓运动不对称性。发现在右偏好的猫中，左侧的H反射比右侧大，反之在左偏好的猫中则相反。在右偏好的猫中，右侧H反射恢复曲线高于左侧。印防己毒素作用后，恢复周期的抑制期消失，并转变为对非偏好侧的易化。士的宁导致右侧和左侧屈肌神经双侧、近乎同步的运动神经元放电；在右偏好的猫中，源自左侧的放电先于源自右侧的放电。这些结果表明，脊髓运动活动在非偏好侧占主导，这可能是猫使用爪子时进行姿势调整的前提条件。具有四足运动的猫前肢这种不对称运动组织似乎与人类腿部的不对称运动组织相似。
