FISIOLOGIA DEL TONO MUSCOLARE E DELLA POSTURA

The mechanisms responsible for muscle tone, and the relationship between muscle tone, postural tone and body posture are briefly considered. The coordination between posture and intended movement is dealt with in some detail, taking into account the action of the different descending systems onto the spinal motoneurones innervating the postural muscles and the muscles subserving the intended movement. The C3-C4 propriospinal neurones are an example of the tight association between the postural and the voluntary command. The monoaminergic descending systems play an important role in the modulation of motoneuronal excitability, both by directly modifying the membrane potential and by acting onto the pre-motoneuronal interneurones.