Activation of extracellular signal-regulated kinase (ERK) and Delta FosB in emotion-associated neural circuitry after asymptotic levels of active avoidance behavior are attained

作者：Perrotti Linda I^*; Dennis Torry S; Jiao Xilu; Servatius Richard J; Pang Kevin C H; Beck Kevin D

来源：Brain Research Bulletin, 2013, 98: 102-110.

DOI：10.1016/j.brainresbull.2013.07.004

• Wistar Kyoto
• Sprague Dawley
• Anxiety
• Prefrontal cortex
• Dorsal striatum
• Amygdala

Avoidance susceptibility may constitute a vulnerability to develop anxiety disorders, and Wistar-Kyoto (WRY) rats exhibit unique features in their acquisition of avoidance behavior that appear to promote susceptibility to this form of learning, namely the absence of the commonly observed "warm-up" effect. The present study sought to determine if strain differences in acquired avoidance behavior, between WRY and Sprague Dawley rats, could be attributed to differences in dopamine-related plasticity, represented by extracellular signal-regulated kinase (ERR) activity, and prolonged neuronal activation, represented by Delta FosB accumulation, in three key areas of the brain: the medial prefrontal cortex (mPFC), dorsal striatum (DS), and basolateral amygdala (BLA). Consistent with earlier work, WRY rats exhibited a higher level of asymptotic performance of avoidance behavior, which included an absence of warm-up in the first few trials of later training sessions, and they exhibited more non-reinforced anticipatory responses in the single minute prior to the initiation of the first warning signal presentation of each training session. In the brain, phosyphorylated ERK2 (pERK2) activation was higher in avoidance trained rats in both the mPFC and DS, although the difference in DS was mostly observed in WRY rats. Avoidance-training was associated with higher levels of Delta FosB expression in the mPFC of SD rats, but not WRY rats. The strain differences in pERK2 activation in the DS and Delta FosB levels in the mPFC may underlie the strain-specific differences observed in warm-up, the emission of non-reinforced anticipatory responses, and general differences in asymptotic performance of active avoidance behavior. The mPFC and DS require further study as potential neural targets for understanding avoidance susceptibility and, as a result, anxiety vulnerability.

• 出版日期2013-9