A variety of isoforms of mammalian voltage-gated sodium channels have been described. Ten genes encoding sodium channel alpha subunits have been identified, and nine of those isoforms have been functionally expressed in exogenous systems. The alpha subunit is associated with accessory beta subunits in some tissues, and three genes encoding different beta subunits have been identified. The alpha...

of Hebb's theory. Testing this theory would require one and Asif A. Ghazanfar to record from populations of neurons distributed across Department of Neurobiology multiple cortical areas and subcortical nuclei. Using a Duke University Medical Center chronic multiple-electrode recording preparation, Nico-Durham, North Carolina 27710 lelis and coworkers (1995, 1997a) recorded from populations of n...

Two experiments with rats examined the dynamics of well-learned response sequences when reinforcement contingencies were changed. Both experiments contained four phases, each of which reinforced a 2-response sequence of lever presses until responding was stable. The contingencies then were shifted to a new reinforced sequence until responding was again stable. Extinction-induced resurgence of p...

Resurgence is the reappearance of an extinguished behavior when an alternative behavior reinforced during extinction is subsequently placed on extinction. Resurgence is of particular interest because it may be a source of relapse to problem behavior following treatments involving alternative reinforcement. In this article we develop a quantitative model of resurgence based on the augmented mode...