Research Highlight: Breaking the Negative cycle of drug addiction
ENP team leader Manuel Mameli and colleagues just published in Nature Neuroscience an article examining neurophysiological responses in mice following cocaine exposure. The scientists found an enhancement of communication from the lateral habenula, a brain region known to respond to unpleasant events, to another region called the rostromedial tegmental nucleus, in cocaine-exposed mice. This enhancement is long-lasting, persisting for several days after initial drug exposure. The study also shows that a small protein that can disrupt the enhancement of neuronal communication can mitigate depression-like behaviors induced by cocaine withdrawal in mice.
While the potential application for clinical intervention will require further studies, this research identifies candidate molecular and anatomical targets for potentially reducing drug-associated negative emotional states such as depression. It also demonstrates that drug-evoked negative symptoms can be attributed to a specific region of the brain that processes other unpleasant events.
Check out the article:
Frank J Meye, Kristina Valentinova, Salvatore Lecca, Lucile Marion-Poll, Matthieu J Maroteaux, Stefano Musardo, Imane Moutkine, Fabrizio Gardoni, Richard L Huganir, François Georges & Manuel Mameli. Cocaine-evoked negative symptoms require AMPA receptor trafficking in the lateral habenula. Nature Neuroscience. 2 february 2015. doi:10.1038/nn.3923
Keywords: addiction, depression, lateral habenula, synapses, synaptic plasticity
Figure: Cocaine experience leads to the insertion of AMPA receptors in lateral habenula neurons projecting to the rostromedial tegmental nucleus. This molecular process increases synaptic efficacy and produces neuronal hyperexcitability driving drug-mediated depressive-like states in mice.