RT Journal Article SR Electronic T1 Generation and validation of a CRF1:Cre transgenic rat: The role of central amygdala CRF1 in nociception and anxiety-like behavior JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.02.23.432551 DO 10.1101/2021.02.23.432551 A1 Marcus M. Weera A1 Abigail E. Agoglia A1 Eliza Douglass A1 Zhiying Jiang A1 Shivakumar Rajamanickam A1 Rosetta S. Shackett A1 Melissa A. Herman A1 Nicholas J. Justice A1 Nicholas W. Gilpin YR 2021 UL http://biorxiv.org/content/early/2021/08/28/2021.02.23.432551.abstract AB Corticotropin-releasing factor type-1 (CRF1) receptors are critical to stress responses because they allow neurons to respond to CRF released in response to stress. Our understanding of the precise role of CRF1-expressing neuronal populations in CRF-mediated behaviors has been largely limited to mouse experiments due to the lack of genetic tools available to selectively visualize and manipulate CRF1+ cells in rats. Here, we describe the generation and validation of a transgenic CRF1:Cre-tdTomato rat, which expresses a bicistronic iCre-2A-tdTomato transgene directed by 200kb of promoter and enhacer sequence surrounding the Crhr1 cDNA present within a BAC clone, that has been transgenically inserted into the rat genome. We report that Crhr1 and Cre mRNA expression are highly colocalized in CRF1:Cre-tdTomato rats within both the central amygdala (CeA), composed of mostly GABAergic neurons, and in the basolateral amygdala (BLA), composed of mostly glutamatergic neurons. In the CeA, membrane properties, inhibitory synaptic transmission, and responses to CRF bath application in tdTomato+ neurons are similar to those previously reported in GFP+ cells in CRFR1-GFP mice. We show that stimulatory DREADD receptors can be selectively targeted to CeA CRF1+ cells via virally delivered Cre-dependent transgenes, that transfected Cre/tdTomato+ cells are activated by clozapine-n-oxide in vitro and in vivo, and that activation of these cells in vivo increases anxiety-like behavior and nocifensive responses. Given the accuracy of expression in the CRF1:Cre rat, modern genetic techniques used to investigate the anatomy, physiology, and behavioral function of CRF1+ neurons and circuits can now be performed in assays that require the use of rats as the model organism.Impact Statement A novel transgenic rat for studying the role of specific corticotropin-releasing factor type-1 receptor-expressing cell populations in physiology and behavior.Competing Interest StatementDr. Gilpin owns shares in Glauser Life Sciences, Inc., a company with interest in developing therapeutics for mental health disorders. There was no direct link between those interests and the work contained herein.