GABA-Mediated Inactivation of Medial Prefrontal and Agranular Insular Cortex in the XXXX : Contrasting Effects on Hunger- and Palatability-Driven Feeding.

@entity6341 @entity550 @entity3264 @entity3391 @entity140 @entity35 @entity6353
A microanalysis of hunger-driven and palatability-driven feeding was carried out after @entity6341 -mediated inactivation of two frontal regions in @entity35 , the @entity550 ( @entity550 ) and the ventromedial prefrontal cortex (vmPFC). Food and water intake, feeding microstructure, and general motor activity were measured under two motivational conditions: food-deprived @entity35 given standard chow or ad libitum-fed @entity35 given a palatable @entity6353 shake. @entity6341 infusions into the @entity550 diminished intake, total feeding duration, and average feeding bout duration for the palatable-food condition only but failed to alter exploratory-like behavior (ambulation or rearing). In contrast, intra-vmPFC @entity6341 infusions did not alter the overall intake of chow or @entity6353 shake. However, these infusions markedly increased mean feeding bout duration for both food types and produced a modest but significant reduction of exploratory-like behavior. The lengthening of feeding-bout duration and reduction in rearing were mimicked by intra-vmPFC blockade of @entity140 -type but not @entity3391 -type @entity3264 receptors. Neither water consumption nor the microstructure of water drinking was affected by inactivation of either site. These results indicate a regional heterogeneity in frontal control of feeding behavior. Neural processing in @entity550 supports palatability-driven feeding but is not necessary for intake of a standard food under a food-restriction condition, whereas ventromedial prefrontal cortex, and @entity140 signaling therein, modulates the duration of individual feeding bouts regardless of motivational context. Results are discussed in the context of regionally heterogeneous frontal modulation of two distinct components of feeding behavior: reward valuation based upon taste perception ( @entity550 ) vs switching between ingestive and non-ingestive (eg, exploratory-like) behavioral repertoires (vmPFC).
