title: Effects of NMDA and non-NMDA ionotropic glutamate receptors in the medial preoptic area on body temperature in awake rats.
abstract: Glutamate when microinjected at the medial preoptic area (mPOA) influences brain temperature (Tbr) and body temperature (Tb) in rats. Glutamate and its various receptors are present at the mPOA. The aim of this study was to identify the contribution of each of the ionotropic glutamatergic receptors at the mPOA on changes in Tbrand Tbin freely moving rats. Adult male Wistar rats (n=40) were implanted with bilateral guide cannula with indwelling styli above the mPOA. A telemetric transmitter was implanted at the peritoneum to record Tband locomotor activity (LMA). A precalibrated thermocouple wire implanted near the hypothalamus was used to assess Tbr. Specific agonist for each ionotropic glutamate receptor was microinjected into the mPOA and its effects on temperature and LMA were measured in the rats. The rats were also microinjected with the respective ionotropic receptor antagonists, 15min prior to the microinjection of each agonist. Amongst amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), N-methyl-d-aspartate (NMDA) and kainic acid, AMPA increased Tband LMA when injected at the mPOA. Specific antagonists for AMPA receptors was able to attenuate this increase (p<0.005). Pharmacological blockade of NMDA was able to lower Tbronly. Microinjection of kainic acid and its antagonist had no effect on the variables. The finding of the study suggests that activation of the AMPA receptors at the mPOA, leads to the rise in body temperature.
authors.affiliation: Department of Physiology, All India Institute of Medical Sciences, New Delhi 110029, India. Electronic address: sengupta.trina3@gmail.com.
authors.forename: Trina
authors.initials: T
authors.lastname: Sengupta
authors.affiliation: Department of Physiology, All India Institute of Medical Sciences, New Delhi 110029, India. Electronic address: ashok.jaryal@gmail.com.
authors.forename: Ashok Kumar
authors.initials: AK
authors.lastname: Jaryal
authors.affiliation: Department of Physiology, All India Institute of Medical Sciences, New Delhi 110029, India. Electronic address: drhmallick@yahoo.com.
authors.forename: Hruda Nanda
authors.initials: HN
authors.lastname: Mallick
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D007608:Kainic Acid / Q000378:metabolism; D008124:Locomotion / Q000187:drug effects; D008297:Male; D011301:Preoptic Area / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000378:metabolism; D058468:Receptors, Ionotropic Glutamate / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000378:metabolism
chemical_list: D018091:Receptors, AMPA; D058468:Receptors, Ionotropic Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D007608:Kainic Acid
keywords: AMPA; Agonist; Antagonist; Core body temperature; Kainic acid; Locomotor activity; NMDA