Effects of Cannabis Oil on anxiety and panic behavior in male Wistar rats and on the activation of serotonergic neurons

• Grant number: 22/05800-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2022
• End date: December 31, 2022
• Field of knowledge: Humanities - Psychology - Experimental Psychology
• Principal Investigator: Milena de Barros Viana
• Grantee: Márcio Gomes Vieira Junior
• Host Institution: Instituto de Saúde e Sociedade (ISS). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil

Abstract

Among the main constituents of the plant Cannabis sativa are the so-called phytocannabinoids. These substances interact with two kinds of receptors, CB1 and CB2 that are distributed in the nervous system and different organs and peripheral tissues. CB1 receptors are densely expressed on GABAergic interneurons, glutaminergic and serotonergic, in crucial encephalic regions which are responsible for behavior and emotions. An example is the dorsal raphe nucleus, a mesencephalic structure that mediates panic and anxiety-related responses. By being able to interact with different kinds of neural populations, the cannabinoid system can modulate distinct subjective and behavioral responses. Therefore, depending on the concentration of the phytocannabinoids used in the prescribed treatment anxiogenic/panicogenic effects are also observed. The present study aims to evaluate the effects of different oils derived from Cannabis sativa, with distinct concentrations of the phytocannabinoids delta-9-tetrahydrocannabinol (delta-9-THC) and cannabidiol (CBD), produced by the Associação Brasileira de Cannabis Medicinal (ABRACAM), in male Wistar rats submitted to the elevated T-maze (LTE). The model was developed to allow the measurement of behavioral responses related to generalized anxiety and panic disorder. In addition to the LTE, the animals will be submitted to the light/dark model and will be evaluated for locomotor activity. At last, the evaluation of the neuronal systems involved with the behavioral effects observed will be performed using immunohistochemistry for the delta FOS-B protein and for the limiting enzyme for serotonin synthesis, tryptophan hydroxylase, in order to better understand the existing association between the cannabinoid system, the serotonin system, and anxiety/panic.(AU)