[Orthodromic activation of neurons of the cerebellar fastigial nucleus of cats induced by stimulation of pontine nuclei].

Activity of fastigial neurons evoked by stimulation of pontine relay nuclei and sensorimotor region of the cerebral cortex was recorded intracellularly in anaesthetized cats. Orthodromic excitation and inhibition (rarely) occurred both in efferent and intranuclear neurons irrespective of their localization within the nucleus or the level of their background activity. The excitation occurred as single or repeated APs or synaptic depolarization of axodendritic type (slow EPSP or fast prepotentials). Latencies of monosynaptic activation of neurons imply afferent conduction via "fast" and mainly "slow" pontine fibers. Similarities in synaptic organization of cortico-pontine and ponto-fastigial projections as well as features of neurons activation described in literature and obtained in present study suggest common mechanisms of functioning for these links of cortico-ponto-fastigial system of the cat.