The Endocannabinoid, 2-Arachidonoyl Glycerol, Induces Growth Cone Collapse and Neurite Retraction in Growing Peripheral Sensory Neurons

Cannabis has a detrimental impact on the developing nervous system. Therefore, regular consumption of cannabis by pregnant and lactating woman poses a potential risk to neuronal growth in fetuses and infants. Indeed, endogenous cannabis-like molecules called endocannabinoids regulate many physiological processes, including neurogenesis, axon guidance, and synaptic plasticity through CB1 receptors. To investigate the physiological role of CB1 receptors on peripheral sensory nerve growth, the endocannabinoid 2-arachidonoyl glycerol was added to cultured chick dorsal root ganglion neurons. This compound inhibited neurite elongation and induced growth cone collapse in a doseand time-dependent manner. These data suggest that caution should be exercised regarding maternal cannabis use during pregnancy. Because ectopic sprouting and abnormal neuronal network connections are considered to be a cause of neuropathic pain, our current data imply an additional role of endocannabinoids as inhibitors of the formation of painmaintenance networks.