ANYL 332 |
| Many individual neurons within the intact brain fire in stochastic patterns that arise from interactions with the neuronal circuits that they comprise. However, the chemical communication that is evoked by these firing patterns has not been characterized because sensors suitable to monitor subsecond chemical events in micron dimensions have only recently become available. Here we employ voltammetry at carbon-fiber electrodes to examine the dynamics of dopamine concentrations in the nucleus accumbens (NAc) of awake and unrestrained rats. At select locations spontaneous dopamine transient concentration changes are detected, achieving instantaneous concentrations of ~ 50 nM. At other locations, transients were absent even though releasable dopamine was available. These findings reveal an unanticipated spatial and temporal heterogeneity of dopamine transmission within the NAc that may depend upon the firing of specific subpopulations of dopamine neurons. |
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ACS Award in Analytical Chemistry in Honor of James W. Jorgenson
8:30 AM-12:00 PM, Tuesday, August 21, 2007 BCEC -- 104C, Oral
Division of Analytical Chemistry |