title: Behavioural and neuronal activation after microinjections of AMPA and NMDA into the perifornical lateral hypothalamus in rats.
abstract: The perifornical lateral hypothalamic area (PeFLH), which houses orexin/hypocretin (OX) neurons, is thought to play an important role in arousal, feeding, and locomotor activity. The present study examined behavioural effects of activating PeFLH neurons with microinjections of ionotropic glutamate receptor agonists. Three separate unilateral microinjections of either (1) AMPA (1 and 2mM in 0.1 μL artificial cerebrospinal fluid, ACSF) and ACSF, or (2) NMDA (1 and 10mM in 0.1 μL ACSF), and ACSF were made into the PeFLH of adult male rats. Following each injection, the rats were placed into an open field for behavioural scoring for 45 min. Rats were perfused after the third injection for immunohistochemistry for c-Fos and OX to assess the level of activation of OX neurons. Behavioural analyses showed that, as compared to ACSF conditions, AMPA injections produced a dose-dependent increase in locomotion and rearing that persisted throughout the 45 min recording period, and an increase in drinking. Injection of NMDA at 10mM, but not 1mM, induced a transient increase in locomotion and an increase in feeding. Histological analyses showed that while both agonists increased the number of neurons immunoreactive for c-Fos in the PeFLH, only AMPA increased the number of neurons immunoreactive for both c-Fos and OX. There were positive correlations between the number of c-Fos/OX-immunoreactive neurons and the amounts of locomotion, rearing, and drinking. These results support the role of ionotropic glutamate receptors on OX and other neurons in the PeFLH in the regulation of locomotor and ingestive behaviours.
authors: Department of Anatomy and Neurobiology, Faculty of Medicine, Dalhousie University, 1459 Oxford Street, Halifax, Nova Scotia, B3H 4R2, Canada. Fred.Li@dal.ca
authors: Frederick W
authors: FW
authors: Li
authors: Samuel
authors: S
authors: Deurveilher
authors: Kazue
authors: K
authors: Semba
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004327:Drinking Behavior / Q000187:drug effects; D018690:Excitatory Amino Acid Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D005106:Exploratory Behavior / Q000187:drug effects; D005247:Feeding Behavior / Q000187:drug effects; D016762:Genes, fos / Q000235:genetics; D006120:Grooming / Q000187:drug effects; D019416:Head Movements / Q000187:drug effects; D007026:Hypothalamic Area, Lateral / Q000166:cytology / Q000502:physiology*; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins / Q000502:physiology; D008297:Male; D008845:Microinjections; D009043:Motor Activity / Q000187:drug effects; D016202:N-Methylaspartate / Q000008:administration & dosage / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects*; D009479:Neuropeptides / Q000502:physiology; D000068797:Orexins; D051381:Rats; D017208:Rats, Wistar; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D018690:Excitatory Amino Acid Agonists; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins; D016202:N-Methylaspartate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid