Whilst much research has focussed on the effects of endocannabinoids in the adult brain relatively little research has looked at the impact of these same effects in the developing brain of the foetus and neonate. Whilst the brain stem is almost devoid of type 1 cannabinoid receptors (CB1Rs) they are in high concentration in many parts of the midbrain, limbic system, subcortical regions and cerebral and cerebellar cortices 3. Foetal CB1Rs have been shown to play key roles in virtually all aspects of brain development including neural stem cell function, determining the ratio of glial v neuronal differentiation, brain inflammation, axonal growth cone guidance, stem cell niche function and signalling, blood flow signalling, white matter and CNS tract formation, glial cell differentiation, myelination, dendrite formation, neural migration into the developing cortex, synapse formation and integration of newly formed neurons into the neural network. They are also found in high density on endoplasmic reticulum and mitochondria from which latter they indirectly control major issues including cognition, DNA maintenance and repair systems both by supplying energy and by metabolite shuttle and RNA signalling 4 5.
Hence it is not surprising that gestational cannabis has been linked with a clear continuum of defects…