Elizabeth Amadei

BME PhD Defense Presentation

January 26th, 2017 at 12 pm

Emory University, Rollins Research Building, Rm 1052

Thesis Committee Members:

Robert Liu, PhD (Advisor)

Larry Young, PhD (Co-advisor)

Robert Butera, PhD

Joseph Manns, PhD

Samuel Sober, PhD

A dynamic circuit mechanism for social bond formation in female prairie voles

Adult pair bonding involves dramatic changes in the perception and valuation of another individual. One key change is that partners come to reliably activate the brain’s reward system, though the precise neural mechanisms by which partners become rewarding during sociosexual interactions leading to a bond remain unclear. This thesis takes advantage of the prairie vole rodent model of social bonding to record and manipulate a key reward circuit from medial prefrontal cortex (mPFC) to nucleus accumbens (NAcc) during bond formation. Individual variation in the strength of mPFC-NAcc functional connectivity, particularly after the first mating encounter, predicts how quickly animals begin affiliative huddling with their partner. Rhythmically activating this circuit in a social context without mating biases later preference towards a partner, indicating that this circuit’s activity is not just correlated with how quickly animals become affiliative but causally accelerates it. These results provide the first dynamic view of corticostriatal processes involved in bond formation, revealing how social interactions recruit reward systems to drive changes in affiliative behavior.