Edibles that contain ?9-tetrahyrocannabinol (THC), the principal psychoactive ingredient produced by the cannabis plant, are becoming increasingly popular among adolescents, making examination of this method of use on the adolescent developing brain urgently needed. An exciting collaboration between the Stella and Land laboratories led to developing and validating a new model to study how oral self-administration of THC impacts adolescent rodent brain and ensuing behavioral impairment in adulthood. Thus, this model of voluntary oral consumption of THC-gelatin edibles achieves relevant blood THC levels, produces acute cannabimimetic effects and can easily be combined with other drugs, here cannabidiol (CBD). Adolescence is a critical period where maturation of neural systems is still occurring, particularly in the limbic system, and disruption of this maturation by drug use may lead to severe behavioral impairments in adulthood. Our preliminary results highlight one of the first successful self-administration models of THC in rodents, thereby enabling comparisons of the long-term consequences of voluntary THC on brain development and behavioral outcomes. Our new questions are to determine how long-term adolescent use of THC alone or in combination with CBD impacts 1) cannabimimetic response, which may provide insight as to the mechanism of 2) altered signaling within the mesocorticolimbic system, which may determine deficits in 3) adult motivated behavior and pain responses to opioids.
Our aims are to determine:
Aim 1 : Establish optimal THC-THC/CBD consumption regimen by adolescent mice.
Aim 2 : Impact of THC and THC/CBD consumption during adolescence on adult mice behavioral responses to morphine. The completion of these studies, which utilize an innovative mouse model of voluntary oral consumption, will increase our mechanistic understanding of the impact of THC and THC/CBD use on adolescent brain development, and further determine how such perturbations influence motivated behavior and pain response to opioids.
Cannabis is the most widely used drug by adolescents and yet little is known about its effect on the developing brain and ensuing consequences in adulthood. This new R21 grant proposal will determine the impact of voluntary oral use of the phytocannabinoids ?9-tetrahydrocannabinoid (THC) and cannabidiol (CBD), by adolescent mice on their motivated behavior and pain responses to opioids in adulthood. Our work will increase the mechanistic understanding of the specific dysregulation of brain function that is responsible for persistent behavioral deficits.
