Motivation to Eat-AgRP Neurons and Homeostatic Need

Abstract

Activation of AgRP neurons potently induces feeding behaviors; however, whether this activity is involved in motivations of feeding behavior is unclear. A recent study in Nature (Betley et al., 2015) reports that AgRP neuron activity conditions learned behavior by transmitting a negative-valence signal: linking AgRP neurons to the preference of environmental cues associated with homeostatic need.

Figure 1. Optogenetic and Chemogenetic Conditioning of Flavor and Place Cues

(A) Animals avoided flavor and place cues associated with optogenetically induced AgRP neuronal activity. Conversely, animals preferred flavor and place cues associated with chemogenetic inhibition of AgRP neurons. (B) AgRP neuronal activity visualized from deep-brain calcium imaging in freely moving mice during different energy states (i.e., nutrient deprived [fasted] and eating). AgRP neuronal activity decreased in the discovery or consumption of food (blue line). Objects of non-nutritive value (false food: red line) failed to sustain decreased AgRP neuronal activity.