Role of endocannabinoids in brain development

In addition to those functions that have been extensively addressed in this special issue, such as nociception, motor activity, neuroendocrine regulat ion, immune function and others, the endogenous cannabinoid system seems to play also a role in neural development. This view is based on a three-fold evidence. A first evidence emerges from neurotoxicological studies that sh owed that synthetic and plant-derived cannabinoids, when administered to pr egnant rats, produced a variety of changes in the maturation of several neu rotransmitters and their associated-behaviors in their pups, changes that w ere evident at different stages of brain development. A second evidence com es from studies that demonstrated the early appearance of elements of the e ndogenous cannabinoid system (receptors and ligands) during the brain devel opment. The atypical location of these elements during fetal and early post natal periods favours the notion that this system may play a role in specif ic molecular events related to neural development. Finally, a third evidenc e derives from studies using cultures of fetal glial or neuronal cells. Can nabinoid receptors are present in some of these cultured cells and their ac tivation produced a set of cellular effects consistent with a role of this system in the process of neural development. All this likely supports that endocannabinoids, early synthesized in nervous cells, play a role in events related to development, by acting through the activation of second messeng er-coupled cannabinoid receptors.