Christian E. Bravo Rivera

Prefrontal amygdala interactions, fear conditioning, active avoidance, cognitive neuroscience.

The labs mission is to:

1. increase understanding of how the brain overcomes fear;
2. train effective scientific thinkers who value communication and collaboration; and
3. increase neuroscience practice in historically underrepresented countries.

Our lab studies the mechanisms of emotional regulation focusing on extinction of conditioned fear.  Much of what is known about extinction comes from animal models using Pavlovian fear conditioning, where a tone stimulus is paired with a shock.  One subregion of the prefrontal cortex, the infralimbic cortex (IL), is necessary for fear extinction (fear inhibition) whereas another mPFC subregion, the prelimbic cortex (PL), is necessary for fear expression.  We suggest that IL inhibits fear by inhibiting amygdala output, whereas PL drives fear by increasing amygdala output.  We examine these and related areas in fear conditioning as well as active avoidance of fear conditioned stimuli, using a variety of experimental techniques in behaving rats: cannulation of specific drugs, electrical stimulation, multichannel unit recording, immunocytochemistry, optogenetics, and computational modeling.  Our research is funded by the National Institute of Mental Health, and is relevant to the treatment of anxiety disorders such as post-traumatic stress and obsessive-compulsive disorder.