Low n-3s Adversely Affect Synaptic Function

BORDEAUX, France—Insufficient intake of omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs) may adversely affect synaptic function in the brain, causing behavioral alterations, according to a new study (Nat Neurosci. ePub 30 Jan 2011; DOI: 10.1038/nn.2736). Researchers coordinated out of INSERM U862, Neurocentre Magendie, and INRA UMR, Nutrition and Integrative Neurobiology, noted low levels of omega-3 EFAs have been linked to neuropsychiatric diseases, although the underlying alterations in synaptic functions have not been elucidated. In a mouse model, the team found lifelong omega-3 LC-PUFA dietary insufficiency impacts long-term synaptic depression mediated by endocannabinoids in the prelimbic prefrontal cortex and accumbens. Specifically, the presynaptic cannabinoid CB1 receptors (CB1Rs) that normally respond to endocannabinoids were uncoupled from the effector Gi/o proteins. In addition, the dietary-induced reduction of CB1R functions in mood-controlling structures was associated with impaired emotional behavior. The researchers said the findings suggest a plausible synaptic substrate for the behavioral and mood alterations caused by the deficiency in omega-3 LC-PUFAs often seen in Western diets.