title: Gustatory functions, sodium appetite, and conditioned taste aversion survive excitotoxic lesions of the thalamic taste area.
abstract: Rats with bilateral, electrophysiologically guided, ibotenic acid lesions of the gustatory thalamus (THLX) were tested for their ability to perform a variety of taste-guided behaviors. First, in daily 30-min sessions, the rats were given repeated 10-s access periods to a range of concentrations of sucrose, NaCl, or QHCl, plus water. Both the control and the THLX rats exhibited similar concentration-response functions, regardless of hydrational state. Next, on 3 trials, the rats were given 15 min access to 0.3 M l-alanine and then injected with LiCl (0.15 M, 1.33 ml/100 g body weight ip). All rats learned a taste aversion following 1 pairing with LiCl. Finally, on 3 separate occasions, the rats were injected with furosemide, and Na(+)-appetite was evaluated 24 hr later. All rats expressed an equivalent sodium appetite after the first furosemide injection, but only the control rats increased intake of 0.51 M NaCl with repeated sodium depletions. These observations reinforce prior data implying that an intact gustatory thalamus is not necessary for the expression of some taste-guided behaviors.
authors.affiliation: Department of Biomedical Science, Universitá di Modena, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Scalera
authors.forename: P S
authors.initials: PS
authors.lastname: Grigson
authors.forename: R
authors.initials: R
authors.lastname: Norgren
mesh_terms: D000818:Animals; D001066:Appetite / Q000502:physiology*; D001245:Association Learning / Q000502:physiology; D001362:Avoidance Learning / Q000502:physiology*; D001931:Brain Mapping; D003214:Conditioning, Classical / Q000502:physiology*; D019422:Dietary Sucrose / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004326:Drinking / Q000502:physiology*; D007051:Ibotenic Acid; D018021:Lithium Chloride / Q000633:toxicity; D008297:Male; D009042:Motivation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012982:Sodium, Dietary / Q000008:administration & dosage*; D013649:Taste / Q000502:physiology*; D013787:Thalamic Nuclei / Q000502:physiology*; D014882:Water-Electrolyte Balance / Q000502:physiology*
chemical_list: D019422:Dietary Sucrose; D012982:Sodium, Dietary; D007051:Ibotenic Acid; D018021:Lithium Chloride