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

PABLO NICOLÁS DE FRANCESCO; SPRING VALDIVIA; AGUSTINA CABRAL; PATRONE ANABELA; MIRTA REYNALDO; MARIO PERELLÓ

Congreso; Sociedad Argentina de Neurociencias. XXVIII Annual Meeting.; 2013

The corticotrophin releasing factor (CRF)-producing neurons of the centralamygdala (CeA) have been implicated in mediating behavioral and physiologicalresponses associated with fear, anxiety, stress and reward. However, difficulties inidentifying CRF neurons of the CeA have previously complicated the study of thisset of neurons. To overcome this problem, we report a novel transgenic mouse linein which humanized green fluorescent protein (GFP) is under the control of the CRFpromoter (CRF-GFP mice), rendering CRF neurons readily recognizable. Using c-Fosas a marker of neuron activation we explored the response of CeA CRF neuronsunder different experimental paradigms. As expected, CeA CRF neurons wereactivated in mice exposed to a social defeat protocol, confirming their role in stressresponses. We then explored a number of different conditions also known toactivate the CeA. In particular, CRF-GFP mice were exposed to either: 1-ghrelintreatment, 2-melanocortin 4 receptor agonist treatment, 3-a conditioned tasteaversion paradigm, 4-a high fat diet binging paradigm, 5-a high fat diet withdrawalparadigm. Despite most of these strategies caused a significant increase of c-Fos inthe CeA, we could not detect a significant increase of c-fos expression in CeA CRFneurons. Hence, thus far, our results suggest that CeA CRF neurons are solelyinvolved in stress-induced responses. Overall, this novel CRF-GFP line is a promisingtool to dissect the role of this CeA subset.