Current Drug Targets

Francis J. Castellino
Kleiderer-Pezold Professor of Biochemistry
Director, W.M. Keck Center for Transgene Research
Dean Emeritus, College of Science
230 Raclin-Carmichael Hall, University of Notre Dame
Notre Dame, IN 46556


Working Memory in ADHD: Prefrontal/Parietal Connections

Author(s): F Levy and M Farrow

Affiliation: correspondence to this author at the Avoca Clinic, Prince of Wales Hospital, Sydney, NSW 2031, Australia


Current theories of dopaminergic and noradrenergic mechanisms, which are thought to be of importance in the regulation of attention are reviewed. A biphasic model of dopaminergic function is described, in which tonic dopamine exerts a suppressive influence on subcortical dopamine systems by altering tonic/phasic dopaminergic relationships. Noradrenergic mechanisms are of importance in modulating sensory processing at the prefrontal cortical level. The work of Silberstein and colleagues utilizing Steady-State Visually Evoked Potential, during the course of an A-X Continuous Performance Task enables examination of the spatial distribution and dynamics of electrical brain activity during the task. The maintenance of activation in the interval between A and X provides a measure of working memory, thought to be related to prefrontal-parietal activation, which is facilitated by administration of methylphenidate to children with ADHD, suggesting that working memory may be a core deficiency in children with ADHD. While tonic dopamine activity in vental striatum/accumbens gates inhibitory activity, dorsolateral prefrontal-parietal connections allow maintenance of working memory required for goal completion.

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Article Details

Page: [347 - 352]
Pages: 6
DOI: 10.2174/1389450013348155
Price: $58