Merridee J. Lefner

Reward and punishment contingency shifting reveals distinct roles for VTA dopamine and GABA neurons in behavioral flexibility

This study examines how VTA dopamine and GABA neurons adapt to reward and punishment contingency shifts in rats, revealing distinct roles in behavioral flexibility.

Reduction of Grin2a in adolescent rat dopamine neurons confers a phenotype relevant to psychosis

This study shows that reducing Grin2a in adolescent rat dopamine neurons leads to psychosis-like behaviors and dopamine signaling abnormalities relevant to schizophrenia.

Critical periods when dopamine controls behavioral responding during Pavlovian learning

This study shows that dopamine receptor antagonism affects Pavlovian learning differently depending on training phase and task type, with persistent deficits only in reward size tasks during the expression phase.

Sex differences in behavioral responding and dopamine release during Pavlovian learning

This study investigates sex differences in behavioral responses and dopamine release during Pavlovian learning in rats, finding no sex differences in cue-evoked dopamine but differences in reward-evoked dopamine and behavioral responding.

Dopamine release and its control over early Pavlovian learning differs between the NAc core and medial NAc shell

This study examines dopamine release and its role in early Pavlovian learning in the NAc core and medial NAc shell, finding regional differences in dopamine responses and behavioral control.

Enhanced preference for delayed rewards requires the basolateral amygdala and retrosplenial cortex

The paper shows that sunk temporal costs increase preference for initially less desirable rewards, and this effect depends on the basolateral amygdala and retrosplenial cortex in rats.

Changes in subjective preference do not require dopamine signaling or the orbital frontal cortex

The paper shows that changes in subjective food preference due to temporal costs do not require dopamine signaling or the orbital frontal cortex.

Cocaine experience abolishes the motivation suppressing effect of CRF in the ventral midbrain

This study shows that prior cocaine exposure eliminates CRF's ability to suppress motivation for food rewards but not cocaine intake, suggesting altered neuropeptide function in the VTA.