Pontine and thalamic influences on fluid rewards: III. Anticipatory contrast for sucrose and corn oil.

Article date: 2012/3/27

PubMed ID: 8864266

Journal name: Physiology & behavior (ISSN: 1873-507X)

DOI: 10.1016/j.physbeh.2011.06.008


An anticipatory contrast effect (ACE) occurs when, across daily trials, an animal comes to respond less than normally to a first stimulus when it is followed shortly by a second, more preferred solution. Classically, ACE is studied using a low (L) concentration of saccharin or sucrose, followed by access to a higher (H) concentration of sucrose. Subjects in the control condition have two bouts of access to the weaker solution presented on the same schedule. The ACE is measured by the difference in intake of the first bout low solution between subjects in the low-low (L-L) vs. the low-high (L-H) conditions. Here we used this paradigm with sham feeding rats and determined that nutritional feedback was unnecessary for the development of ACE with two concentrations of sucrose or with two concentrations of corn oil. Next we showed that ibotenic acid lesions centered in the orosensory thalamus spared ACEs for both sucrose and corn oil. In contrast, lesions of the pontine parabrachial nuclei (PBN), the second central relay for taste in the rat, disrupted ACEs for both sucrose and corn oil. Although the sensory modalities needed for the oral detection of fats remain controversial, it appears that the PBN is involved in processing the comparison of disparate concentrations of sucrose and oil reward.

Author List: Liang Nu-Chu, Norgren Ralph, Grigson Patricia S

Publication Types: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't

Article Date: 2011/06/16

Substances mentioned in the article: Sweetening Agents; Sucrose; Corn Oil; Saccharin;

Mesh terms: Analysis of Variance; Animals; Choice Behavior; Conditioning, Operant; Corn Oil/administration & dosage; Dose-Response Relationship, Drug; Drinking Behavior/physiology; Food Preferences/physiology; Male; Motivation/physiology; Pons/injuries; Rats; Rats, Sprague-Dawley; Reaction Time; Reward; Saccharin/administration & dosage; Sucrose/administration & dosage; Sweetening Agents/administration & dosage; Thalamus/injuries; Time Factors;

Citations: - 3742226

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