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CB2 Receptor Role in Anxiety‐like Behavior Using Validated CB2‐KO Zebrafish
Author(s) -
AcevedoCanabal Agnes,
ColonCruz Luis,
Varshney Gaurav,
Behra Martine,
Yudowski Guillermo
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.825.5
Subject(s) - cannabinoid receptor type 2 , cannabinoid receptor , cannabinoid , endocannabinoid system , biology , zebrafish , g protein coupled receptor , receptor , neuroscience , medicine , microbiology and biotechnology , gene , genetics , agonist
More than 100 million people use Marijuana or a synthetic analog worldwide, but effects and side effects are still poorly understood. Most cannabinoids, like Δ9‐tetrahydrocannabinol (Δ9‐THC), the main active constituent of marijuana, modulate the mesocorticolimbic system through binding to two cannabinoid receptors (CBRs) which are present in all vertebrates. The cnr1 and cnr2 genes encode the cannabinoid receptor 1 (CB1) and 2 (CB2), respectively. While CB1 is the most abundant G protein‐coupled receptor (GPCR) in the central nervous system (CNS), CB2 was thought to be primarily expressed in immune cells where it plays a major role in regulating the inflammatory response. However, there is increase evidence for expression and biological roles of CB2 receptor in the CNS. Thus, the goal of our experiments was to identify such role(s) by examining “anxiety‐like” behaviors in larval zebrafish. First, we established CB2‐knockout (CB2‐KO) animals using the CRISPR/Cas9 genome‐editing tool. An allele carrying an early 2bp deletion ( cnr2 2Δ ) in the coding sequence resulted in a loss of function mutation that we validated via Western Blots showing that the CB2 protein was absent in the adult homozygote brains ( cnr2 −/−2D ). Next, we used a larval behavioral assay based on the photo‐dependent swimming response (PDR) and measured three anxiety‐like parameters (1) hyper/hypo activity, (2) Center avoidance and (3) photo‐stimulated startle response (PSSR) in wild type and CB2‐KO larvae. We found that all of those “anxiety‐like” behaviors were affected in the animals lacking CB2, thus clearly establishing this receptor as an important modulator of those behaviors. Support or Funding Information National Institute of Drug Abuse (R01.DA037924) and the National Science Foundation (HRD.1137725)‐Puerto Rico Center for Environmental Neuroscience (PRCEN). This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .