Neural circuits underlying hunger-dependent bias towards food cues

Summary

Date: 
November 1, 2016 - 12:00pm - 1:00pm
Location: 
Northwest 243
About the Speaker
Name: 
Mark Andermann
Speaker Affiliation: 
BIDMC

Abstract:

The needs of the
body can direct behavioral and neural processing towards motivationally
relevant sensory cues. For example, human neuroimaging studies have
consistently found specific cortical areas with biased responses to
food-associated visual cues in hungry subjects, but not in sated subjects. To
obtain a cellular-level understanding of these hunger-dependent cortical
response biases, we performed chronic two-photon calcium imaging in insular
cortex (InsCtx), postrhinal association cortex (POR), and primary visual cortex
(V1) of behaving mice. As in humans, neurons in mouse InsCtx and POR, but not
V1, exhibited biases towards food-associated cues that were abolished by
satiety. These emergent biases were mirrored by the innervation pattern and
hunger-dependent food cue responses in amygdalo-cortical feedback axons. Surprisingly,
we found that chemogenetic activation of hypothalamic AgRP neurons (sensors of
caloric deficit, whose activation induces feeding) in sated mice restored food
cue-biased neuronal population responses in InsCtx. Using AgRP neurons as a
genetic entry-point for circuit mapping, we then uncovered a pathway linking
AgRP neurons to basolateral amygdala and InsCtx. Our findings provide a
framework for understanding how a circuit underlying a specific motivational
drive can selectively bias sensory cortical processing towards motivationally-relevant
cues.