Revealing the role of CRF neurons of the CeA with a novel transgenic mouse model

NICOLAS DE FRANCESCO; SPRING VALDIVIA; AGUSTINA CABRAL; ANABELA PATRONE; MIRTA REYNALDO; MARIO PERELLO

Congreso; XXVIII congreso de la SAN; 2013

SAN

The corticotrophin releasing factor (CRF)-producing neurons of the central amygdala (CeA) have been implicated in mediating behavioral and physiological responses associated with fear, anxiety, stress and reward. However, difficulties in identifying CRF neurons of the CeA have previously complicated the study of this set of neurons. To overcome this problem, we report a novel transgenic mouse line in which humanized green fluorescent protein (GFP) is under the control of the CRF promoter (CRF-GFP mice), rendering CRF neurons readily recognizable. Using c-Fos as a marker of neuron activation we explored the response of CeA CRF neurons under different experimental paradigms. As expected, CeA CRF neurons were activated in mice exposed to a social defeat protocol, confirming their role in stress responses. We then explored a number of different conditions also known toactivate the CeA. In particular, CRF-GFP mice were exposed to either: 1-ghrelin treatment, 2-melanocortin 4 receptor agonist treatment, 3-a conditioned taste aversion paradigm, 4-a high fat diet binging paradigm, 5-a high fat diet withdrawal paradigm. Despite most of these strategies caused a significant increase of c-Fos in the CeA, we could not detect a significant increase of c-fos expression in CeA CRF neurons. Hence, thus far, our results suggest that CeA CRF neurons are solely involved in stress-induced responses. Overall, this novel CRF-GFP line is a promising tool to dissect the role of this CeA subset.