Learning to Inhibit Acquired Fears - Dr Vincent Laurent

What is this research about?

Clinical trials have established that cognitive behavioural therapy is relatively effective for disorders such as post-traumatic stress. A component of this therapy is exposure in which the patient, aided by the clinician, confronts trauma-related cues in the absence of any overt danger. One aim of such confrontations is to reduce, even eliminate, the ability of these cues to elicit the fear and associated avoidance that impair the quality of the patient’s life.

Cue exposure can be modelled in the laboratory via the extinction of conditioned fear. Extinction involves repeated exposure to a feared cue in the absence of any consequence. As a result, the fear to the cue becomes inhibited. The present project uses rodents to study the psychological and neural mechanisms underlying this fear inhibition. A better understanding of these mechanisms should ultimately help improving the efficacy of cue exposure in patients suffering from anxiety disorders.

One main finding originating from this project is that learning to extinguish a fear is not the same as learning again (i.e., relearning) to extinguish that fear. That is, we found that learning and relearning do not require the same brain regions. This finding has strong clinical implications. Indeed, relapse (i.e., the return of fear) after cue exposure is quite common in the clinical population, and more than often, additional cue exposure is required. Our findings suggest that this additional exposure does not require the same mechanisms as the original exposure. Ultimately, this implies that different pharmacological approaches should be employed during initial cue exposure and cue exposure after relapse.

Other researchers involved:

Dr. Nura Lingawi (Post-doctoral Research Associate)

Scientia Professor Fred Westbrook

Publications relating to this research:

Lingawi, N. W., Westbrook, R. F., Laurent, V. (2016). Extinction and Latent Inhibition Involve a Similar Form of Inhibitory Learning that is Stored in and Retrieved from the Infralimbic Cortex. Cerebral Cortex

Holtzman-Assif O., Laurent V., Westbrook R.F. (2010). Blockade of dopamine activity in the nucleus accumbens impairs learning extinction of conditioned fear. Learning and Memory.

Laurent V., Westbrook R.F. (2010). Role of the basolateral amygdala in the reinstatement and extinction of fear responses to a previously extinguished conditioned stimulus. Learning and Memory. 17(2): 86-96.

Laurent V., Westbrook R.F. (2009). Inactivation of the infralimbic but not the prelimbic cortex impairs consolidation and retrieval of fear extinction. Learning and Memory. 16(9): 520-29.

Laurent V., Westbrook R.F. (2009). Infusion of the NMDA receptor antagonist, DL-APV, into the basolateral amygdala disrupts learning to fear a novel and a familiar context as well as relearning to fear an extinguished context. Learning and Memory. 16(1): 96-105.

Laurent V., Westbrook R.F. (2008). Distinct contribution of the basolateral amygdala and the medial prefrontal cortex to learning and relearning extinction of conditioned fear. Learning and Memory. 15(9): 657-66.

Laurent V., Marchand A.R., Westbrook R.F. (2008). The basolateral amygdala is necessary for learning but not relearning extinction of conditioned fear. Learning and Memory. 15(5): 304-14.

Grant

NHMRC Project Grant (2014-2016) – Treatment of relapse in anxiety disorders: an animal model.

Lab:

Decision Neuroscience Laboratory – Westbrook’s lab.