title: Glutamatergic Receptor Activation in the Commisural Nucleus Tractus Solitarii (cNTS) Mediates Brain Glucose Retention (BGR) Response to Anoxic Carotid Chemoreceptor (CChr) Stimulation in Rats.
abstract: Glutamate, released from central terminals of glossopharyngeal nerve, is a major excitatory neurotransmitter of commissural nucleus tractus solitarii (cNTS) afferent terminals, and brain derived neurotrophic factor (BDNF) has been shown to attenuate glutamatergic AMPA currents in NTS neurons. To test the hypothesis that AMPA contributes to glucose regulation in vivo modulating the hyperglycemic reflex with brain glucose retention (BGR), we microinjected AMPA and NBQX (AMPA antagonist) into the cNTS before carotid chemoreceptor stimulation in anesthetized normal Wistar rats, while hyperglycemic reflex an brain glucose retention (BGR) were analyzed. To investigate the underlying mechanisms, GluR2/3 receptor and c-Fos protein expressions in cNTS neurons were determined. We showed that AMPA in the cNTS before CChr stimulation inhibited BGR observed in aCSF group. In contrast, NBQX in similar conditions, did not modify the effects on glucose variables observed in aCSF control group. These experiments suggest that glutamatergic pathways, via AMPA receptors, in the cNTS may play a role in glucose homeostasis.
authors: Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Ave. 25 de Julio 965, Col. Villas de San Sebastián, Colima, Col C.P. 28045, México.
authors: R
authors: R
authors: Cuéllar
authors: S
authors: S
authors: Montero
authors: S
authors: S
authors: Luquín
authors: J
authors: J
authors: García-Estrada
authors: O
authors: O
authors: Dobrovinskaya
authors: V
authors: V
authors: Melnikov
authors: M
authors: M
authors: Lemus
authors: E Roces
authors: ER
authors: de Álvarez-Buylla
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002344:Carotid Body / Q000502:physiology*; D005947:Glucose / Q000378:metabolism*; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000502:physiology; D017470:Receptors, Glutamate / Q000502:physiology*; D017552:Solitary Nucleus / Q000502:physiology*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
chemical_list: D011810:Quinoxalines; D018091:Receptors, AMPA; D017470:Receptors, Glutamate; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D005947:Glucose