helps mediate the detrimental effects that the increased NMDA currents would have. Current and future research Additional research is needed to obtain a broader understanding of nonsynaptic plasticity. Topics that should be further explored include: Local versus global excitability changes in neuronal networks and maintenance of the memory trace Specificity of induction of learning-dependent excitability changes Manipulation of learning-dependent excitability changes by pharmaceutical products or genetic mutations and their effects on the memory trace Similarities between the molecular mechanisms of synaptic and nonsynaptic plasticity Comparison of in vivo patterns of nonsynaptic plasticity with in vitro results Alterations in gene expression produced by neural activity References Memory Neuroplasticity Neurology Neurophysiology Neural circuits