PT  - JOURNAL ARTICLE
AU  - John W. Muschamp
AU  - Ashlee Van't Veer
AU  - Aram Parsegian
AU  - Miranda S. Gallo
AU  - Melissa Chen
AU  - Rachael L. Neve
AU  - Edward G. Meloni
AU  - William A. Carlezon, Jr
TI  - Activation of CREB in the Nucleus Accumbens Shell Produces Anhedonia and Resistance to Extinction of Fear in Rats
AID  - 10.1523/JNEUROSCI.5973-10.2011
DP  - 2011 Feb 23
TA  - The Journal of Neuroscience
PG  - 3095--3103
VI  - 31
IP  - 8
4099  - http://www.jneurosci.org/content/31/8/3095.short
4100  - http://www.jneurosci.org/content/31/8/3095.full
SO  - J. Neurosci.2011 Feb 23; 31
AB  - Stress triggers psychiatric conditions including depressive and anxiety disorders. The mechanisms by which stress produces persistent changes in behavior are not fully understood. Here we show in rats that stress (footshock) activates the transcription factor cAMP response element binding protein (CREB) within the nucleus accumbens shell (NAS), a brain area involved in encoding reward and aversion. To examine the behavioral significance of altered CREB function in the NAS, we used viral vectors to elevate or disrupt CREB in this region. Elevated CREB produced increases in intracranial self-stimulation thresholds, a depressive-like sign reflecting anhedonia (decreased sensitivity to reward), whereas disruption of CREB function by expression of a dominant-negative CREB had the opposite effect. To determine whether neuroadaptations that produce anhedonia subsequently affect vulnerability to stress-induced behavioral adaptations, we subjected rats with altered CREB function in the NAS to fear conditioning. Although neither elevation nor disruption of CREB function altered the development of conditioned fear, elevation of CREB impaired extinction of conditioned fear. To mimic downstream effects of CREB activation on expression of the opioid peptide dynorphin, we microinjected the κ-opioid receptor (KOR) agonist U50,488 directly into the NAS. KOR stimulation produced anhedonia but had no effect on expression or extinction of conditioned fear. These findings demonstrate that activation of CREB in the NAS produces multiple behavioral signs (anhedonia, impaired extinction) characteristic of experience-dependent psychiatric conditions such as posttraumatic stress disorder. Although CREB activation is a common trigger, expression of these individual signs appears to involve divergent downstream mechanisms.