title: The pyramidal system of the cat and of the monkey: neurophysiologic aspects of phylogenetic advancement.
abstract: The pyramidal motor system underwent dramatic phylogenetic developments. Ethologically, this has found expression in higher capacities for accurate movements. An hypothesis and supporting data are offered that this depends on the advancement in the higher species of a system based on the attainment of higher accuracy by an increase in the number of channels, an increased range of conduction velocity values, an increase in surround effects of the PTN and the evolvement of a stochastically based mechanism the accuracy of operation of which depends at least on the above-mentioned factors.
mesh_terms: D000818:Animals; D002415:Cats / Q000502:physiology*; D000882:Haplorhini / Q000502:physiology*; D009431:Neural Conduction; D010802:Phylogeny; D011712:Pyramidal Tracts / Q000502:physiology*; D012453:Saimiri / Q000502:physiology*