The Effect of Antihistamines on the Nervous System of Crayfish

Kallie A. Taylor, Tobenna C. Obi, Chioma L. Okafor, Alizah A. Edwards

Agnes Scott College, Department of Biology, Class of 2023 

Crayfish are arthropods that have been commonly used as a model organism for  research by the scientific community for decades. These organisms rely on aggression responses  in order to survive on a day to day basis. Behaviours such as claw raising and grappling are some  examples of an aggression response. In order to experiment on reducing the aggression responses  of crayfish, a proposed method would involve inhibiting antihistamines. As histamine controls  the neurotransmitters in the human brain, promoting wakefulness, it serves to reason that  antihistamines would inhibit this effect, causing lethargy to occur. Despite the amount of  research released that explores this effect in the human nervous system, the amount of studies on  how compounds such as antihistamines can affect the behaviour and nervous system of  crayfishes is limited. The proposed experiment will investigate how antihistamines—in this case  liquid benadryl— will affect aggression behaviours in the Louisiana crayfish also known as  Procambarus clarkia.  

For this experiment, it is hypothesized that if crayfish are given an antihistamine such as  benadryl, the frequency of aggressive behaviours from the organism will decrease. The treatment  tank of crayfish will be given a constant daily dosage of benadryl, alongside a control tank given  none. Both groups of crayfish will have their behavior observed during crayfish checks, feedings,  and tank cleanings. By analyzing the effect of benadryl on the aggression responses of crayfish,  the scientific community can obtain more information on the effect of antihistamines on the brain  and nervous system, exploring how such substances can impact long term behavior. 

Key words: procambarus clarkia, crayfish, aggression, diphenhydramine, central nervous