Differential Gene Expression Analysis with Altered Local CRH Signaling in the Mouse Olfactory Bulb

We report genome-wide gene expression changes in olfactory bulb cells, in the context of low, wild-type or high levels of local CRH signaling by local interneurons onto adult-born CRHR1+ granule neurons. To test the gene expression changes associated with altered local CRH signaling, we utilize the following animal models: CRHR1-/- mice whose bulbs were infected with a control AAV-flex-EGFP virus = low local CRH signaling, CRHR1-Cre mice whose bulbs were infected with AAV-flex-EGFP = pseudo-wild-type local CRH signaling, and CRHR1-Cre mice whose bulbs were infected with AAV-flex-(CA)CRHR1, which is a constitutively active variant of CRHR1 = high local CRH signaling. We find that, in response to changes in local CRH signaling in the bulb, the largest ontological category of transcription changes in the bulb that occurs reciprocally between low and high levels of CRH signaling are gene regulatory factors. To test the contributions of one of these factors, POU6f1, we perform loss- and gain-of-function analysis. We show that CRHR1 activation results in transcriptional activation of POU6f1 and that POU6f1 in turn influences synaptogenesis and dendritic patterning of adult-born neurons and olfactory circuit behavior. gene expression changes associated with altered local CRH signaling