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March 10, 2005


Researcher published in the Journal of Neuroscience
Remember novel and surprising events

By Deborah Inkpen

We remember novel and surprising events. New data from Memorial University researchers published in the Journal of Neuroscience suggests a special group of cells in the brain, the locus coeruleus (literally, blue place because it contains blue pigment in human brain), have a key role in making new memories following novel or surprising happenings.

Dr. Carolyn Harley, professor in Memorial’s Department of Psychology, and her colleagues, former doctoral students Bob Brown and Sue Walling, and Steve Milway, a laboratory instructor in psychology, published the article, Locus Coeruleus Activation Suppresses Feed Forward Interneurons and Reduces Beta/Gamma EEG Frequencies While Enhancing Theta Frequencies in Rat Dentate Gyrus in the Feb. 23, 2005, issue of the journal.

“This cell group releases a chemical related to adrenaline (noradrenaline),” said Dr. Harley. “This chemical is released in the brain whenever new or exciting things happen.” The researchers turned on the locus coeruleus cells experimentally and looked in a memory area of the brain. They found normal inhibition was turned off by noradrenaline release and memory cells were much more excited by input. They also saw the EEG switch in the memory area from frequencies thought to mediate old memories to frequencies that promote new memories.

“This is the first study to look at effects of natural release of noradrenaline in a memory area,” explained Dr. Harley. “Earlier studies applied the brain chemical artificially and did not see this exciting pattern of results.”

Dr. Brown is currently at UCLA on a postdoctoral fellowship and Ms. Walling is at Mount Allison on a one-year contract in psychology. Ms. Walling has had two paper published in the Journal of Neuroscience previously and won a Brain Star award from CIHR.