title: SKF 83566 attenuates the effects of ghrelin on performance in the object location memory task.
abstract: Increasing research implicates ghrelin, a metabolic signaling peptide, in memory processes including acquisition, consolidation, and retention. The present study investigated the effects of ghrelin on spatial memory acquisition by utilizing the object location memory task paradigm. Given the co-expression of ghrelin and dopamine D(1) receptors within hippocampal neurons, we examined a potential interaction between these two systems on memory performance. When injected into the dorsal third ventricle (D3V) of male Sprague-Dawley rats, proximal to hippocampal tissue, ghrelin (500 pmol) increased the amount of time spent with objects in novel locations. This effect was completely reversed by the D(1) antagonist SKF 83566 (100 μg/kg IP), although when administered alone, the antagonist had no effect on task performance (10-100 μg/kg). We also examined the feeding effects of D3V ghrelin and found that the peptide reliably increased food intake (500 pmol) but that this effect was not blocked by SKF 83566 (100 μg/kg). When given alone, SKF 83566 did not alter food intake (10-100 μg/kg). Our findings indicate that, in addition to an orexigenic effect, ghrelin improves acquisition of spatial location memories. Furthermore, D(1) receptor activation is necessary for ghrelin to improve the encoding of spatial memories but does not impact the increase in food intake elicited by the peptide.
authors: Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, USA.
authors: Sarah M
authors: SM
authors: Jacoby
authors: Paul J
authors: PJ
authors: Currie
mesh_terms: D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000633:toxicity; D000818:Animals; D001066:Appetite / Q000187:drug effects / Q000502:physiology; D004298:Dopamine / Q000502:physiology; D018492:Dopamine Antagonists / Q000494:pharmacology* / Q000633:toxicity; D004435:Eating / Q000187:drug effects; D005106:Exploratory Behavior / Q000187:drug effects / Q000502:physiology; D054439:Ghrelin / Q000037:antagonists & inhibitors* / Q000502:physiology; D007276:Injections, Intraventricular; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology; D008297:Male; D008569:Memory Disorders / Q000139:chemically induced / Q000503:physiopathology; D011597:Psychomotor Performance / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000187:drug effects / Q000502:physiology*; D013037:Spatial Behavior / Q000187:drug effects / Q000502:physiology*
chemical_list: D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D004298:Dopamine; D018492:Dopamine Antagonists; D054439:Ghrelin; D017447:Receptors, Dopamine D1; C044846:SKF83566