Discharge pattern of neurons of the dorsal spinocerebellar tract activated by static extension of primary endings of muscle spindles.

Abstract
Impulses of single axons of the dorsal spinocerebellar tract activated from primary spindle afferents of ankle flexor or extensor muscles have been recorded in Nembutal anesthetized cats. There is a background activity in the cells in the absence of primary afferent input. The mean frequency of firing increases approximately linearly with increasing muscle length. The standard deviation of interval distributions at various levels of excitation increases nearly linearly with the mean interval. The background firing of the cells is usually more regular. There is a marked negative serial correlation between the duration of neighboring intervals. The findings are discussed in relation to a quanta! excitation model of nerve cells.