Discharge behaviour of feline gamma-motoneurones following induction of an artificial myositis

摘要: The study was undertaken to test the widely held hypothesis that a painful lesion of skeleto-motor system leads an increase in neuromuscular component muscle tone by activating gamma-motoneurones affected region. In chloralose-anaesthetized cats, artificial myositis induced lateral gastrocnemius-soleus (LGS) and several hours later impulse activity recorded from single gamma-motoaxons supplying medial gastrocnemius (MG) muscle. Under conditions study, majority fusimotor neurones had resting could be readily excited natural stimuli. contrast assumptions working hypothesis, animals were not activated but showed strong inhibition; both excitability electrical stimuli decreased. Additional recordings flexor (tibialis anterior, TA) demonstrated preparation used, behaviour different extensor ones former usually no did respond only discernible effect LGS on TA decrease their reflex threshold. results do support assumption is followed activation gamma-loop tone. Instead, data may offer explanation for weakness and--in chronic cases--the atrophy lesioned muscles.