Orexin-induced feeding requires NMDA receptor activation in the perifornical region of the lateral hypothalamus
| Autor: | J. Lee Beverly, Dolores Fernandez Doane, Marcus A. Lawson, Jonathan R. Meade, Catherine M. Kotz |
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| Rok vydání: | 2007 |
| Předmět: |
Male
medicine.medical_specialty Microinjections Lateral hypothalamus Physiology Microdialysis Neuropeptide Biology Receptors N-Methyl-D-Aspartate Rats Sprague-Dawley Eating chemistry.chemical_compound Physiology (medical) Internal medicine medicine Animals Sympathomimetics Neurotransmitter Orexins Neuropeptides digestive oral and skin physiology Intracellular Signaling Peptides and Proteins Glutamate receptor Orexin receptor Rats Orexin Endocrinology 2-Amino-5-phosphonovalerate nervous system chemistry Hypothalamic Area Lateral NMDA receptor Luteinizing hormone Excitatory Amino Acid Antagonists |
| Zdroj: | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 293:R1022-R1026 |
| ISSN: | 1522-1490 0363-6119 |
| Popis: | Food intake is stimulated following administration of orexin-A into the perifornical region of the lateral hypothalamus (LH/PFA). Orexin neurons originating in the LH/PFA interact with a number of hypothalamic systems known to influence food intake, including glutamatergic neurons. Glutamatergic systems in the LH/PFA were demonstrated to initiate feeding through N-methyl-d-aspartic acid (NMDA) receptors. Male Sprague-Dawley rats fitted with brain guide cannulas to the LH/PFA were used in two experiments. In the first experiment, a combination microdialysis/microinjection probe was used to deliver artificial cerebrospinal fluid (aCSF) or 500 pmol of orexin-A into the LH/PFA. Orexin-A increased interstitial glutamate to 143 ± 12% of baseline ( P < 0.05), which remained elevated over the 120-min collection period. In the second experiment, the NMDA receptor antagonist d-2-amino-5-phosphonopentanoic acid (d-AP5; 10 nmol) was administered before orexin-A. The orexin-induced increase in food intake (from 1.1 ± 0.4 to 3.2 ± 0.5 g, P < 0.05) during the first hour was absent in rats receiving d-AP5 + orexin-A (1.2 ± 0.5 g). There was no effect of d-AP5 alone on food intake. These data support glutamatergic systems in the LH/PFA mediating the feeding response to orexin-A through NMDA receptors. |
| Databáze: | OpenAIRE |
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