Our experiences — the things we see, hear or do
— can trigger long-term changes in the strength of
the connections between nerve cells in our brain, and these
persistent changes are how the brain encodes information as
memory. As reported in Neuron July 19, Johns
Hopkins researchers have discovered a new biochemical
mechanism for memory storage, one that may have a
connection with addictive behavior.
Previously, the long-term changes in connection were
thought to involve only a fast form of electrical signaling
in the brain, electrical blips lasting about 100th of a
neuroscience professor David Linden and his colleagues
have shown that another, much slower form of electrical
signaling lasting about a second can also be persistently
changed by experience.
They simulated natural brain activity by applying
short electrical jolts to slices of rat brain and measuring
the current flowing across the cells. After repeated
jolting, the strength of the slow nerve signals had
dramatically decreased and remained at a low intensity for
30 minutes after electrical jolts ceased.
These slow signals are produced by a nerve cell
receptor called mGluR1, which has been associated with
behaviors such as addiction and epilepsy.
"Both of these conditions also involve long-term
changes in the function of nerve connections, Linden
said. "So in addition to furthering our basic understanding
of memory storage, our work suggests that drugs designed to
alter mGluR1 are promising candidates for the treatment of
addiction, epilepsy and diseases of memory.
The research was funded by the Republic of Korea
Ministry of Health and Welfare and the National Institutes
Authors on the paper are Paul Worley and Linden, of
Johns Hopkins; and Sang Jeong Kim, Yunju Jin and Jun Kim,
of Seoul National University College of Medicine.