Acute D-amphetamine administration to rats leads to the release of arachidonic acid (AA, 20:4n-6) as a second messenger following indirect agonism at dopamine D2-like receptors in brain. We hypothesized that chronically administered D-amphetamine in rats also would alter brain AA metabolism and signaling. To test this, adult male rats were injected i.p. daily for 2 weeks with saline or 2.5 mg/kg D-amphetamine. After a 1-day washout, the unanesthetized rats were injected acutely with i.v. saline, 1 mg/kg quinpirole (a D2-like receptor agonist) or 5.0 mg/kg SKF-38393 (a D1-like receptor agonist), followed by i.v. [1-14C]AA. The AA incorporation coefficient k* (brain radioactivity/integrated plasma radioactivity), a marker of AA signaling and metabolism, was quantified using autoradiography in each of 62 brain regions. Compared with chronic saline, chronic D-amphetamine widely decreased baseline values of k* in brain regions having D2-like receptors. On the other hand, chronic amphetamine did not alter the k* responses to quinpirole seen in chronic saline treated rats. SKF-38393 had minimal effects on k* in both chronic saline and amphetamine treated rats, consistent with D1-like receptors are not being coupled to AA signaling. The ability of chronic D-amphetamine after 1 day washout to downregulate baseline values of k* likely reflects neuroplastic changes in brain AA signaling, and may correspond to depressive behaviors noted following withdrawal from chronic amphetamine in humans and in rats.