SKF 83566 attenuates the effects of ghrelin on performance in the object location memory task.
Summary of "SKF 83566 attenuates the effects of ghrelin on performance in the object location memory task."
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 (500pmol) increased the amount of time spent with objects in novel locations. This effect was completely reversed by the D(1) antagonist SKF 83566 (100μg/kg IP), although when administered alone, the antagonist had no effect on task performance (10-100μg/kg). We also examined the feeding effects of D3V ghrelin and found that the peptide reliably increased food intake (500pmol) but that this effect was not blocked by SKF 83566 (100μg/kg). When given alone, SKF 83566 did not alter food intake (10-100μg/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.
Affiliation
Department of Psychology, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97202, United States.
Journal Details
This article was published in the following journal.
Name: Neuroscience letters
ISSN: 1872-7972
Pages: 316-20
Links
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/21982806
- DOI: http://dx.doi.org/10.1016/j.neulet.2011.09.056
Medical and Biotech [MESH] Definitions
Ghrelin
A 28-amino acid, acylated, orexigenic peptide that is a ligand for GROWTH HORMONE SECRETAGOGUE RECEPTORS. Ghrelin is widely expressed but primarily in the stomach in the adults. Ghrelin acts centrally to stimulate growth hormone secretion and food intake, and peripherally to regulate energy homeostasis. Its large precursor protein, known as appetite-regulating hormone or motilin-related peptide, contains ghrelin and obestatin.
Receptors, Ghrelin
Transmembrane proteins that recognize and bind GHRELIN, a potent stimulator of GROWTH HORMONE secretion and food intake in mammals. Ghrelin receptors are found in the pituitary and HYPOTHALAMUS. They belong to the family of G-PROTEIN-COUPLED RECEPTORS.
Chromosomal Position Effects
The effects on gene expression that depend on the location of a gene with respect to its neighboring genes and region of chromosome. Stable position effects are sequence dependent. Variegated position effects depend on whether the gene is located in or adjacent to HETEROCHROMATIN or EUCHROMATIN.
Rotarod Performance Test
A performance test based on forced MOTOR ACTIVITY on a rotating rod, usually by a rodent. Parameters include the riding time (seconds) or endurance. Test is used to evaluate balance and coordination of the subjects, particular in experimental animal models for neurological disorders and drug effects.
Gymnotiformes
An order of neotropical electric fish found chiefly in the waters of South America. They continually emit weak electric discharges, which they use in object location and communication. A most popular species of research interest is the electric eel, ELECTROPHORUS electricus.
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