Nutritional n-3 PUFA Deficiency Abolishes Endocannabinoid Gating of Hippocampal Long-Term Potentiation.

“Maternal n-3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid, is critical during perinatal brain development. How early postnatal n-3 PUFA deficiency impacts on hippocampal synaptic plasticity is mostly unknown. Here we compared activity-dependent plasticity at excitatory and inhibitory synapses in the CA1 region of the hippocampus in weaned pups whose mothers were fed with an n-3 PUFA-balanced or n-3 PUFA-deficient diet. Normally, endogenous cannabinoids (eCB) produced by the post-synapse dually control network activity by mediating the long-term depression of inhibitory inputs (iLTD) and positively gating NMDAR-dependent long-term potentiation (LTP) of excitatory inputs. We found that both iLTD and LTP were impaired in n-3 PUFA-deficient mice. Pharmacological dissection of the underlying mechanism revealed that impairment of NMDAR-dependent LTP was causally linked to and attributable to the ablation of eCB-mediated iLTD and associated to disinhibitory gating of excitatory synapses. The data shed new light on how n-3 PUFAs shape synaptic activity in the hippocampus and provide a new synaptic substrate to the cognitive impairments associated with perinatal n-3 deficiency.”

http://www.ncbi.nlm.nih.gov/pubmed/26946127

Nutritional n-3 polyunsaturated fatty acids deficiency alters cannabinoid receptor signaling pathway in the brain and associated anxiety-like behavior in mice.

“N-3 polyunsaturated fatty acids (PUFAs) cannot be synthesized de novo in mammals and need to be provided by dietary means. In the brain, the main n-3 PUFA is docosahexaenoic acid (DHA), which is a key component of neuronal membranes. A low dietary level of DHA has been associated with increased risk of developing neuropsychiatric diseases; however, the mechanisms involved remain to be determined.

In this study, we found that long-term exposure to an n-3 deficient diet decreases the level of DHA in the brain and impairs the cannabinoid receptor signaling pathway in mood-controlling structures.

In n-3 deficient mice, the effect of the cannabinoid agonist WIN55,212-2 in an anxiety-like behavior test was abolished. In addition, the cannabinoid receptor signaling pathways were altered in the prefrontal cortex and the hypothalamus.

Consequently, our data suggest that behavioral changes linked to an n-3 dietary deficiency are due to an alteration in the endocannabinoid system in specific brain areas.”

http://www.ncbi.nlm.nih.gov/pubmed/22707188