Cannabinoid CB1 receptor is known to play an important role on the neuronal development such as columnar formation in cortex or age-related changes of cognitive function. Interestingly, aged CB1 receptor-deficient mice show a marked cognitive decline, whereas young CB1 knockouts show better cognition than wild-type mice. However how CB1 influence the neuronal function in very young age like infants is unknown, majorly due to lack of in-vivo/ex-vivo evaluation systems such as behavioral tests and primary cell cultures in this particular age. Thus, this study aims to generate primary cultured neurons from infant-to-toddler mice (2-3 weeks old), which has been difficult to do so far, and to evaluate whether they can be used as an ex-vivo model to analyze the neural activity these mice.
We used modified version of manufacturer‘s protocol by Miltenyi Biotec. While this protocol is designed to culture the neurons from adult mice up to p60, our modified protocol could culture the neurons from neonatal (P7), young (P50), and mature (P105) mice at least for 3 to 10 days which was good enough to grow axons. This result suggests that our modified method is suitable to evaluate neuronal growth and cell activity even after a certain ageing period like P105. However, since our method is restricted to the whole brain, we are currently trying to culture neurons harvested from specific brain regions. Our final goal is to establish the primary cultures from infant CB1 knockouts as well as DAGL-alpha knockouts, to study the effects of CB1-related endocannabinoid deficiency on neuronal growth and cell activity in infants-toddlers.