Altered endocannabinoid metabolism compromises the brain-CSF barrier and exacerbates chronic deficits after traumatic brain injury in mice

Endocannabinoids [2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine (AEA)], endogenously produced arachidonate-based lipids, are anti-inflammatory physiological ligands for two known cannabinoid receptors, CB1 and CB2, yet the molecular and cellular mechanisms underlying their effects after brain injury are poorly defined. In the present study, we hypothesize that traumatic brain injury (TBI)-induced loss of endocannabinoids exaggerates neurovascular injury, compromises brain-cerebrospinal fluid (CSF) barriers (BCB) and causes behavioral dysfunction. Preliminary analysis in human CSF and plasma indicates changes in endocannabinoid levels. This encouraged us to investigate the levels of endocannabinoid-metabolizing enzymes in a mouse model of controlled cortical impact (CCI). Reductions in endocannabinoid (2-AG and AEA) levels in plasma were supported by higher expression of their respective metabolizing enzymes, monoacylglycerol lipase (MAGL), fatty acid amide hydrolase (FAAH), and cyclooxygenase 2 (Cox-2) in the post-TBI mouse brain. Following increased metabolism of endocannabinoids post-TBI, we observed increased expression of CB2, non-cannabinoid receptor Transient receptor potential vanilloid-1 (TRPV1), aquaporin 4 (AQP4), ionized calcium binding adaptor molecule 1 (IBA1), glial fibrillary acidic protein (GFAP), and acute reduction in cerebral blood flow (CBF). The BCB and pericontusional cortex showed altered endocannabinoid expressions and reduction in ventricular volume. Finally, loss of motor functions and induced anxiety behaviors were observed in these TBI mice. Taken together, our findings suggest endocannabinoids and their metabolizing enzymes play an important role in the brain and BCB integrity and highlight the need for more extensive studies on these mechanisms.

Infant predictors of cognitive development in an undernourished Kenyan population

Assessments of infant sociability, motoric capacities, and nutritional factors were performed to elucidate early influences on infant development in an undernourished Kenya population. In this longitudinal study, infant social skills were assessed using both the Bayley Behavior Record and home observations during the first 6 months of the infants' lives. Abilities were measured using an adapted version of the Bayley scales of infant development at 6 and 30 months, and a short battery of cognitive measures at 5 years. Infant size measurements were used as indicators of infant nutritional status. Shorter and lighter infants, and those infants showing growth faltering in weight attainment, were significantly less sociable at 6 months than infants who were taller and maintained heavier weights. Infants with smaller arm circumferences displayed lower motor scores at 6 months and lower Bayley mental scores at 30 months than infants with greater arm circumference. Furthermore, infants who were more motorically able and socially adept at 6 months had higher Bayley scores at 30 months and higher verbal comprehension scores at 5 years.

Impact of a temporary food shortage on children and their mothers

Kenya experienced a severe drought and temporary food shortage during a study on mild malnutrition. Effects of the temporary food shortage on energy intake, weight, and behaviors were evaluated in schoolchildren and in toddlers and their mothers. Schoolchildren were seriously affected, showing significant declines in their energy intake, age-corrected weight, activity on the playground, and classroom attention. Toddlers appear to have been somewhat protected since their energy intake, weight, and play and language behaviors were stable. Maternal caregiving of toddlers declined for the group as a whole, but individually those mothers who maintained family food levels delegated responsibility for toddlers to other caregivers. While the food shortage affected poorer families more than those of higher SES, declines in the behaviors of schoolchildren occurred regardless of SES and previous level of nutrition, suggesting that food shortages can have behavioral consequences for schoolchildren in all communities.