Do dopamine signals promote flexible behavior by recruiting synchronized brain rhythms?
Problems with cognition are the major cause of disability in schizophrenia. One idea is that these result from having too little dopamine in a part of the brain called the prefrontal cortex. Another idea is that abnormalities in a particular class of neurons called parvalbumin interneurons, and the brain rhythms that these neurons generate (gamma oscillations), contribute to cognitive problems in schizophrenia. We have developed new methods for measuring gamma oscillations in parvalbumin interneurons while mice perform cognitive tasks. We will now use these methods to test our hypothesis, that dopamine signals in the parvalbumin interneurons trigger gamma oscillations at critical moments during tasks.
Gamma oscillations may help the brain learn new behaviors in order to adapt to a changing world. Besides providing insight into how our brains normally learn, this could reveal a “missing link” between two factors which contribute to cognitive problems in schizophrenia. This could lead to the development of drugs which target dopamine receptors in parvalbumin interneurons in order to treat schizophrenia.