Department of Physiology, Louisiana State University Health Sciences Center, New Orleans, United States
Abigail E Agoglia
Department of Pharmacology, University of North Carolina, Chapel Hill, United States
Eliza Douglass
Department of Pharmacology, University of North Carolina, Chapel Hill, United States
Zhiying Jiang
Institute of Molecular Medicine, University of Texas Health Sciences Center, Houston, United States
Shivakumar Rajamanickam
Institute of Molecular Medicine, University of Texas Health Sciences Center, Houston, United States
Rosetta S Shackett
Department of Physiology, Louisiana State University Health Sciences Center, New Orleans, United States
Melissa A Herman
Department of Pharmacology, University of North Carolina, Chapel Hill, United States; Bowles Center for Alcohol Studies, University of North Carolina, Chapel Hill, United States
Nicholas J Justice
Institute of Molecular Medicine, University of Texas Health Sciences Center, Houston, United States; Department of Integrative Biology and Pharmacology, McGovern Medical School at UT Health, Houston, United States
Department of Physiology, Louisiana State University Health Sciences Center, New Orleans, United States; Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, United States; Alcohol & Drug Abuse Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, United States; Southeast Louisiana VA Healthcare System (SLVHCS), New Orleans, United States
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 role of CRF1-expressing neurons 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. We report that Crhr1 and Cre mRNA expression are highly colocalized in 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 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 and nocifensive behaviors. Outside the amygdala, we show that Cre-tdTomato is expressed in several brain areas across the brain, and that the expression pattern of Cre-tdTomato cells is similar to the known expression pattern of CRF1 cells. 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 can now be performed in assays that require the use of rats as the model organism.
