Dopamine suppresses persistent network activity via D(1) -like dopamine receptors in rat medial entorhinal cortex.
European Journal of Neuroscience
Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
Cortical networks display persistent activity in the form of periods of sustained synchronous depolarizations ('UP states') punctuated by periods of relative hyperpolarization ('DOWN states'), which together form the slow oscillation. UP states are known to be synaptically generated and are sustained by a dynamic balance of excitation and inhibition, with fast ionotropic glutamatergic excitatory and GABAergic inhibitory conductances increasing during the UP state. Previously, work from our group demonstrated that slow metabotropic GABA receptors also play an important role in terminating the UP state, but the effects of other neuromodulators on this network phenomenon have received little attention. Given that persistent activity is a neural correlate of working memory and that signalling through dopamine receptors has been shown to be critical for working memory tasks, we examined whether dopaminergic neurotransmission affected the slow oscillation. Here, using an in vitro model of the slow oscillation in rat medial entorhinal cortex, we showed that dopamine strongly and reversibly suppressed cortical UP states. We showed that this effect was mediated through D1 -like and not D2 -like dopamine receptors, and we found no evidence that tonic dopaminergic transmission affected UP states in our model.
This work was supported by the Wellcome Trust OXION initiative (M.T.C. and O.P.) and a National Institute of Child Health and Human Development (NICHD) intramural award (C.J.M.). M.T.C. held a Wellcome Trust Prize Studentship. E.W.M. is supported by the NIH MD/PhD Partnership Training programme and by the Rhodes Trust.
Research Support, N.I.H., Intramural
Research Support, Non-U.S. Gov't
This is the final version of the article. Available from Wiley via the DOI in this record.
Vol. 37, Iss. 8, April 2013, pp. 1242 - 1247
Place of publication