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.
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.
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.