Western Diet and the Weakening of the Interoceptive Stimulus Control of Appetitive Behavior
Autor: | Camille H. Sample, Terry L. Davidson, Sabrina Jones, Leonard E. Jarrard, Sara L. Hargrave |
---|---|
Jazyk: | angličtina |
Rok vydání: | 2016 |
Předmět: |
Male
Food deprivation Sucrose Hippocampus Hippocampal formation Article Developmental psychology Interoception Discrimination Learning Rats Sprague-Dawley 03 medical and health sciences Behavioral Neuroscience Eating 0302 clinical medicine medicine Animals 0501 psychology and cognitive sciences 050102 behavioral science & comparative psychology Discrimination learning Reinforcement Cholecystokinin Appetitive Behavior 05 social sciences Rats Diet Western medicine.symptom Cues Psychology Stimulus control Food Deprivation Neuroscience Weight gain 030217 neurology & neurosurgery |
Popis: | In obesogenic environments food-related external cues are thought to overwhelm internal cues that normally regulate energy intake. We investigated how this shift from external to internal stimulus control might occur. Experiment 1 showed that rats could use stimuli arising from 0 and 4h food deprivation to predict sucrose delivery. Experiment 2 then examined (a) the ability of these deprivation cues to compete with external cues and (b) how consuming a Western-style diet (WD) affects that competition. Rats were trained to use both their deprivation cues and external cues as compound discriminative stimuli. Half of the rats were then placed on WD while the others remained on chow, and external cues were removed to assess learning about deprivation state cues. When tested with external cues removed, chow-fed rats continued to discriminate using only deprivation cues, while WD-fed rats did not. The WD-fed group performed similarly to control groups trained with a noncontingent relationship between deprivation cues and sucrose reinforcement. Previous studies provided evidence that discrimination based on interoceptive deprivation cues depends on the hippocampus and that WD intake could interfere with hippocampal functioning. A third experiment assessed the effects of neurotoxic hippocampal lesions on weight gain and on sensitivity to the appetite-suppressing effects of the satiety hormone cholecystokinin (CCK). Relative to controls, hippocampal-lesioned rats gained more weight and showed reduced sensitivity to a 1.0 ug but not 2.0 or 4.0 ug CCK doses. These findings suggest that WD intake reduces utilization of interoceptive energy state signals to regulate appetitive behavior via a mechanism that involves the hippocampus. |
Databáze: | OpenAIRE |
Externí odkaz: |