The O'Donnell lab
at the Department
of Anatomy & Neurobiology and Program in Neuroscience
|
Information Processing in the Nucleus Accumbens |
Funded by NIH grant R01 MH60131 |
This project explores whether the ventral striatum serves as a "behavioral switchboard". A widely accepted model of the mode the NA integrates inputs from diverse cortical region posits that hippocampal afferents can gate other inputs by setting NA medium spiny neurons into a depolarized "up state". Recent work from our lab revealed that up states can also be driven by strong prefrontal inputs. Furthermore, in awake behaving rats at rest or exploring their environment, the NA is tightly synchronized with the ventral hippocampus, particularly in theta oscillations. NA theta rhythms follow hippocampal theta rhythms, indicating a hippocampal-to-NA flow of information in that behavioral condition. When the animals engage in a goal-directed behavior in the same recording session, the NA loses theta activity, disengages from hippocampal rhythms that persist and engages with slower oscillations that emerge transiently in the medial prefrontal cortex.
We are now exploring whether strong prefrontal inputs (i.e., burst of pulses) can attentuate synaptic responses to hippocampal and other afferents using in vivo intracellular recordings in anesthetized rats. The potential involvement of local inhibitory interneurons, dopamine and cannabinoids is being tested. We are also exploring those interactions in brain slices containing the NA, using optogenetic tools.