Ethanol-Modulated Camouflage Response Screen in Zebrafish Uncovers a Novel Role for cAMP and Extracellular Signal-Regulated Kinase Signaling in Behavioral Sensitivity to Ethanol

Abstract

Ethanol, a widely abused substance, elicits evolutionarily conserved behavioral responses in a concentration-dependent manner in vivo. The molecular mechanisms underlying such behavioral sensitivity to ethanol are poorly understood. While locomotor-based behavioral genetic screening is successful in identifying genes in invertebrate models, such complex behavior-based screening has proven difficult for recovering genes in vertebrates. Here we report a novel and tractable ethanol response in zebrafish. Using this ethanol-modulated camouflage response as a screening assay, we have identified a zebrafish mutant named fantasma ( fan), which displays reduced behavioral sensitivity to ethanol. Positional cloning reveals that fan encodes type 5 adenylyl cyclase (AC5). fan/ac5 is required to maintain the phosphorylation of extracellular signal-regulated kinase (ERK) in the forebrain structures, including the telencephalon and hypothalamus. Partial inhibition of phosphorylation of ERK in wild-type zebrafish mimics the reduction in sensitivity to stimulatory effects of ethanol observed in the fan mutant, whereas, strikingly, strong inhibition of phosphorylation of ERK renders a stimulatory dose of ethanol sedating. Since previous studies in Drosophila and mice show a role of cAMP signaling in suppressing behavioral sensitivity to ethanol, our findings reveal a novel, isoform-specific role of AC signaling in promoting ethanol sensitivity, and suggest that the phosphorylation level of the downstream effector ERK is a critical "gatekeeper" of behavioral sensitivity to ethanol.

Towards a Comprehensive Catalog of Zebrafish Behavior 1.0 and Beyond

“…), a part of social behavior (e.g., display, fight or courtship), 42 as well as a result of stress/sickness, or drug-evoked dispersion (skin darkening) or aggregation (paling) of melanophores. 85 Specific drugs (e.g., alcohol, ibogaine 86,87 ) evoke robust skin darkening in adult zebrafish, while some factors (e.g., cold exposure, pathogens) can evoke paling (e.g., sickness behavior). Coloration response can be assessed manually (by visual inspection) or using automated (luminescence-based) tools.…”

“…Occurs due to melanophore dispersion (skin darkening) or aggregation (paling). 83,84,86 Part of body color change response; in fish phenotyping literature represents 'expanded melanophore phenotype' (e.g., lack of body color change may indicate deficits in light perception, leaving the larva in a dark adapted pigmentation state). 1.27.…”

Recent advances with a novel model organism: Alcohol tolerance and sensitization in zebrafish (Danio rerio)

“…Acute alcohol exposure has been shown to alter neurotransmitter systems (Gerlai et al, 2009), hormonal systems (Cachat et al, 2010; Tran et al, unpublished manuscript), cell signalling cascades (Peng et al, 2009), enzymatic activity (Chaterjee et al, 2014) and gene expression in the zebrafish brain (Rosemberg et al, 2010a). One limitation regarding the use of zebrafish in neurobiological research is the organism’s small size and thus the difficulties associated with processing and handling its tiny brain.…”

Zebrafish for the Study of the Biological Effects of Nicotine

“…Behavioral assays define changes induced by drug exposure and enable differential molecular analysis of the resulting transcriptional (i.e., gene expression) and epigenetic states (Kane, Konu, Ma, & Li, 2004;Kumar et al, 2005;Levine et al, 2005;Nestler, 2008;Renthal et al, 2007;Romieu et al, 2008;Shen et al, 2008). As the reinforcing properties of addictive drugs are highly conserved, behavioral assays have been adapted to zebrafish to study addiction to cocaine (Darland & Dowling, 2001), ethanol (Lockwood, Bjerke, Kobayashi, & Guo, 2004;Peng et al, 2009), amphetamines (Ninkovic & Bally-Cuif, 2006;Webb et al, 2009), and opiates (Bretaud et al, 2007;Lau, Bretaud, Huang, Lin, & Guo, 2006;Sanchez-Simon & Rodriguez, 2008). A broad perspective review of zebrafish use in the study of addiction and other neuropsychiatric disorders has been published (Mathur & Guo, 2010).…”