Regulation of transient dopamine concentration gradients in the microenvironment surrounding nerve terminals in the rat striatum

Dopamine Receptor Stimulation Modulates AMPA Receptor Synaptic Insertion in Prefrontal Cortex Neurons

“…The lower, D 1 -preferring, concentrations of DA correspond to those measured in the PFC during working memory tasks in rats (Phillips et al, 2004). DA levels may reach micromolar concentrations near release sites before diffusing away to nanomolar concentrations in the extracellular space (Kawagoe et al, 1992;Garris and Wightman, 1994). High micromolar concentrations associated with particularly alerting stimuli or stress may selectively activate D 2 receptors closer to release sites, rather than the predominantly extrasynaptic D 1 receptors (Smiley et al, 1994;Yung et al, 1995;Caille et al, 1996).…”

Detecting Subsecond Dopamine Release with Fast-Scan Cyclic Voltammetry in Vivo

“…In the striatum, these tonic concentrations of dopamine are predicted to be [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] nmol/L by microdialysis (9 ) and differential normalpulse voltammetry (10 ) and 50 -100 nmol/L by theoretical estimations using fast-scan cyclic voltammetry (11 ) and pharmacologic studies (12 ). If the concentrations are indeed 20 nmol/L or above, those dopamine receptors in high-affinity states would be chronically occupied, which appears to be the case for D 2 -like receptors (13,14 ).…”

Anti-hyperactivity medication: methylphenidate and amphetamine

“…These two important factors regulate the time-course of the rise in extracellular dopamine, and thereby determine the magnitude of the therapeutic benefit or the stimulant effects and the degree of abuse liability. [23][24][25][26] Stimulant drugs raise extracellular dopamine, but reduce pulsatile dopamine relative to the resting level The normal resting or basal level of extracellular dopamine is approximately 4 nM, [27][28][29] and transiently rises at least 60-fold to about 250 nM during a normal nerve impulse. This transiently elevated level of extracellular dopamine falls back to 4 nM, primarily by diffusion 29 but assisted by the dopamine transporter, as illustrated in Figure 3 (A and B).…”