Novel chronic pain model in zebrafish (Danio rerio): Nociceptive, motivational and cognitive response to the treatment with Cannabis sp. oil

• Grant number: 24/13308-8
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2025
• End date: February 28, 2029
• Field of knowledge: Biological Sciences - Zoology - Animal Behavior
• Principal Investigator: Percilia Cardoso Giaquinto
• Grantee: Gustavo Venâncio da Silva
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Chronic pain is a global health concern, with low treatment success rates and complex behavioral outcomes. Cannabis-based treatment has the potential to successfully treat chronic pain through modulation of the endocannabinoid system. However, there are gaps remaining in basic research about the neuromodulatory and analgesic effect of Cannabis. Zebrafish is a powerful animal model due to its complex behavior repertoire, high genomic homology to humans and low maintenance cost. Despite that, there is not a well established chronic pain model in zebrafish yet, as well as the effects of Cannabis-based treatment have not been addressed. Our aim is to, in addition to establish a chronic pain model in zebrafish, to investigate the effects of Cannabis-based treatment on chronic pain nociception, motivation and cognition. Chronic pain will be induced by intraperitoneal injection of Freund's Complete Adjuvant and Cannabis oil will be administered within chow. This project will be divided into three experiments. The first experiment will investigate nociceptive and hyperalgesic response through locomotion analyses, and tissues will be collected to evaluate inflammation and central sensitization. The second experiment will evaluate the motivational response to explore a new tank. The third experiment will evaluate cognition through associative and non-associative learning using conditioned place preference and object recognition tests, respectively. This project will approach chronic pain deeper than only nociception, as well as correlate the behavioral findings with molecular and physiological parameters.