Mice have been genetically engineered to prevent them from becoming addicted to cocaine.
Scientists in Canada created mice that produce higher levels of a protein that normally strengthens the connections between brain cells.
Extra levels of the protein, called cadherin, appeared to make it difficult for a brain cell to receive a signal from others nearby so the pleasurable memory of the cocaine did not remain.
The discovery could help develop new drugs to treat addiction.
For normal learning, scientists must be able to both weaken and strengthen synapses.
That plasticity allows for the pruning of some neural pathways and the formation of others, enabling the brain to adapt and to learn.
Ideally scientists need to find a molecule that blocks formation of a memory of a drug-induced high, while not interfering with the ability to remember important things.
Through genetic engineering, scientists hard-wired in place the synapses in the reward circuits of these mice.
By preventing the synapses from strengthening, they have prevented the mutant mice from 'learning' the memory of cocaine, and thus prevented them from becoming addicted."
