Polyunsaturated free fatty acids (FFAs) have long been considered beneficial to memory and learning due to their role in moderating neurotransmission. However, the roles of other FFAs and phospholipids found in the brain are not as well understood. A research team from the University of Queensland Brain institute recently studied FFA and phospholipid levels in the brains of rats after memory formation and made the unexpected discovery that saturated FFAs increased significantly in the amygdala.
For the study, rats were exposed to auditory fear conditioning (AFC) and then FFAs and phospholipids were extracted from different regions of their brains. The concentrations of each analyte in each region of the brain were determined through ultra high performance liquid chromatography mass spectrometry (UHPLC-MS).
The tests revealed a marked increase in saturated FFAs, especially saturated myristic acid, in the amygdalas of rats exposed to AFC, along with a decrease in phospholipids. In contrast, the brains of rats exposed to AFC that had their NMDA receptors blocked with CPP, to reduce long-term fear memory acquisition, showed decreases in all FFAs and phospholipids. The study was published in Nature Communications.
“This research has huge implications on our understanding of synaptic plasticity—the change that occurs at the junctions between neurons that allow them to communicate, learn and build memories,” said Pankaj Sah, a study contributor and director of the Queensland Brain Institute.
Sah said the team’s brain-wide profile of FFA and phospholipid changes after memory acquisition opens a new avenue for studying how memories are formed.