Brazil: Impact of Omega-3 PUFAs on Seizure and Memory Loss

Dietary omega-3 polyunsaturated fatty acids (n-3 PUFAs) had a positive impact on the glutamatergic system during seizure and helped in the prevention of seizure-related memory loss in adulthood, according to a recent study in the journal Nutritional Neuroscience.

The glutamatergic system is a fast-signalling system essential for processing of information in neuronal networks of the neocortex and hippocampus in particular. Glutamate is involved in the long-term potentiation process which is a neuronal model of memory.

Omega-3s are found naturally in some foods and are added to some fortified foods. The dietary sources of omega-3s include:

• Fish and other seafood
• Nuts and seeds
• Plant oils
• Fortified foods such as certain brands of eggs, yogurt, juices, milk, soy beverages

Júlia D. Moreira, Universidade Federal de Santa Catarina, Brazil, and colleagues investigated the influence of dietary n-3 PUFAs on glutamatergic system modulation after a single episode of neonatal seizures and their possible effects on seizure-induced long-lasting behavioral deficits.

Male Wistar rats receiving an omega-3 diet (n-3) or an n-3 deficient diet (D) from the prenatal period were subjected to a kainate-induced seizure model at P7. Glutamate transporter activity and immunocontents (GLT-1 and GLAST) were assessed in the hippocampus at 12, 24, and 48 h after the seizure episode. Fluorescence intensity for glial cells (GFAP) and neurons (NeuN) was assessed 24 h after seizure in the hippocampus. Behavioral analysis (elevated-plus maze and inhibitory avoidance memory task) was performed at 60 days of age.

Key Findings of the Study

• The D group showed a decrease in glutamate uptake 24 h after seizure.
• In this group only, the GLT1 content increased at 12 h, followed by a decrease at 24 h.
• GLAST increased up to 24 h after seizure. GFAP fluorescence was higher, and NeuN fluorescence decreased, in the D group independent of seizures.
• In adulthood, the D group presented memory deficits independent of seizures, but short-term memory (1.5 h after a training session) was abolished in the D group treated with kainate.

"N-3 PUFA positively influenced the glutamatergic system during seizure and prevented seizure-related memory deficits in adulthood," concluded the authors.

The study, "Dietary omega-3 fatty acids prevent neonatal seizure-induced early alterations in the hippocampal glutamatergic system and memory deficits in adulthood," is published in the journal Nutritional Neuroscience.

DOI: https://www.tandfonline.com/doi/full/10.1080/1028415X.2020.1837569