Genotype for hypocretin receptor (hcrtr2) affects appetite in zebrafish

Area of Science:

• Neuroscience
• Behavioral Biology
• Genetics

Background:

• Hypocretin, a neuropeptide, influences circadian rhythms and appetite.
• The hypocretin receptor 2 (hcrtr2) is implicated in various physiological processes.
• Zebrafish (Danio rerio) serve as a valuable model organism for studying neurobiology and behavior.

Purpose of the Study:

• To investigate the role of hypocretin receptor 2 (hcrtr2) in appetite signaling in zebrafish.
• To determine if genetic modification of hcrtr2 affects feeding rate.
• To elucidate the neurobiological mechanisms underlying appetite regulation.

Main Methods:

• Utilized wild-type and heterozygous hcrtr2 knockout zebrafish (hu2098 mutant).
• Developed a novel imaging technique to quantify individual brine shrimp consumption.
• Implemented food restriction followed by an 8-minute feeding trial to measure feeding rate.

Main Results:

• Heterozygous hcrtr2 knockout zebrafish exhibited a significantly faster feeding rate compared to wild-type fish.
• Feeding rate was analyzed using a mixed-effects ANCOVA model, controlling for body mass.
• The mean feeding rate for heterozygous fish was 23.4 shrimp/min versus 20.5 shrimp/min for wild-type fish (p=0.033).

Conclusions:

• The findings support a significant role for hypocretin receptor 2 (hcrtr2) in the regulation of appetite.
• This study provides evidence for the involvement of the hypocretin system in controlling feeding behavior in zebrafish.
• Further research can explore the specific neural pathways modulated by hcrtr2 in appetite control.