CHICAGO: A single dose of morphine was found to lower the inhibitions of rats, even after the drug had left their systems, a finding that may help scientists better understand addiction in humans, US researchers said on Wednesday.
In rats, the painkiller blocked the brain's ability to strengthen connections, or synapses, that ratchet down reward or pleasure, researchers from Brown University reported in the journal Nature.
"What we have found is that the inhibitory synapses can no longer be strengthened 24 hours after treatment with morphine, which suggests that a natural brake has been removed," said Julie Kauer, a professor of molecular pharmacology, physiology and biotechnology at Brown.
"This happens 24 hours after the animal had one dose of morphine. There is no morphine left in the brain. It shows that it is a persistent effect of the drug," she said in a telephone interview.
Kauer said the finding adds to a growing body of evidence suggesting a link between learning and addiction and may help in the development of drugs to treat addiction. "Strengthening synapses, we think, is the beginning of the formation of memory," she said. More
In rats, the painkiller blocked the brain's ability to strengthen connections, or synapses, that ratchet down reward or pleasure, researchers from Brown University reported in the journal Nature.
"What we have found is that the inhibitory synapses can no longer be strengthened 24 hours after treatment with morphine, which suggests that a natural brake has been removed," said Julie Kauer, a professor of molecular pharmacology, physiology and biotechnology at Brown.
"This happens 24 hours after the animal had one dose of morphine. There is no morphine left in the brain. It shows that it is a persistent effect of the drug," she said in a telephone interview.
Kauer said the finding adds to a growing body of evidence suggesting a link between learning and addiction and may help in the development of drugs to treat addiction. "Strengthening synapses, we think, is the beginning of the formation of memory," she said. More
