Descartes' law of reciprocal innervation

Reciprocal innervation plays a crucial role in the fine motor control exhibited in body movements and this is especially true for the precise ocular rotations demanded of the extrinsic muscles of the eye. Although Galen, in 157 AD, was knowledgeable in human anatomy and muscle function, it was Descarted, who in 1626 first conceived of model for the nervous system controller, of a muscular mechanism for movement of the extra-ocular plant, and of reciprocal innervation as the linking principle to provide for control of agonist and antagonist muscles. Bell, in 1826, and Sherrington in 1893, clearly demonstrated reciprocal innervation in their experimental animals. Additional qualitative neurophysiological evidence supporting the concept of reciprocal innervation has been provided by clinical case reports, by electromyographic recording from the extraocular muscles, and by monitoring single unit activity in the extraocular motor nuclei. Recently the applicatio of bioengineering concepts, such as time optimal control and quantitative models to elucidate the nature of the neural signals sent by the brain to command eye movements have further emphasized the importance of Descartes' "Law of Reciprocal Innervation."