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In vivo Imaging of Optic Nerve Fiber Integrity by Contrast-Enhanced MRI in Mice
Published on: July 22, 2014
The alpha-2A noradrenergic receptor agonist guanfacine improves visual object discrimination reversal performance in
1Section of Neurobiology, Yale Medical School, New Haven, Connecticut 06510-8001, USA.
Abstract:
Administration of either low or high doses of the alpha-2A adrenergic agonist guanfacine (GFC) to aged monkeys has been shown to improve performance of the delayed-response task, a task linked to the dorsolateral prefrontal cortex (dlPFC). Monkeys treated with higher guanfacine doses also appeared less disinhibited, suggesting enhanced ventromedial-orbital PFC (vmPFC) function. To test this hypothesis, the current study examined the effects of low versus high doses of GFC on reversal of a visual object discrimination task, a task particularly sensitive to vmPFC lesions. The results of this study showed that high (0.1 mg/kg) but not low (0.00001-0.001 mg/kg) doses of GFC significantly improved reversal performance in aged monkeys. These results may be relevant to GFC's calming effects in attention deficit hyperactivity disorder.

