title: Blocking glutamate receptors in the waist area of the parabrachial nucleus decreases taste reactivity behaviors in conscious rats.
abstract: The "waist" area (W) of the parabrachial nucleus contains neurons that receive orosensory input and play a role in the initiation of oromotor behaviors. Immunohistochemical data indicate that neurons in W receive glutamatergic input and express glutamate receptors, but a behavioral role for glutamate neurotransmission within W has not been investigated. To determine the role of specific glutamate receptors in taste reactivity behaviors, glutamate receptor blockers were delivered into W by reverse microdialysis during intraoral infusion of 0.1 M sodium chloride, 0.1 M sucrose, 0.03 M hydrochloric acid, and 0.003 M quinine hydrochloride. Blocking alpha-amino-3-hydroxy-5-methyl-isoxazolepropionate (AMPA)/kainate ionotropic glutamate receptors in W with 6-cyano-7-nitroquinoxaline-2,3-dione disodium (CNQX) reduced ingestive taste reactivity behaviors to each tastant by 72-85% compared with baseline levels (P's < 0.05). Blocking N-methyl-D-aspartate receptors as well as type 1 and group III metabotropic glutamate receptors had minor effects on taste reactivity responses to the tastants. These data provide strong evidence for a behavioral role of glutamatergic neurotransmission in W in conscious rats.
authors.affiliation: Biology Department, Stetson University, DeLand, FL 32723, USA.
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Biondolillo
authors.forename: Learnel A
authors.initials: LA
authors.lastname: Williams
authors.forename: Michael S
authors.initials: MS
authors.lastname: King
mesh_terms: D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism* / Q000601:surgery; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism; D007608:Kainic Acid / Q000494:pharmacology; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009435:Synaptic Transmission / Q000187:drug effects* / Q000502:physiology; D013649:Taste / Q000187:drug effects / Q000502:physiology*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
chemical_list: D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D018698:Glutamic Acid; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D007608:Kainic Acid