Communication between areas in the brain and cognition
Previous research indicates that cognition relies on the integrity of local neural synchrony controlled by interneuron networks and a range of neuromodulators. Theta oscillations in the hippocampus (HPC) are heavily implicated in learning and memory. These oscillations are also thought to induce coherence in principal cells in the medial prefrontal cortex (mPFC). Furthermore, inhibitory neurons containing parvalbumin (PV) in mPFC may play a major role in the theta coherence observed between mPFC and HPC. The EU-funded NEURODYNAMICS (Inhibition and neuromodulation in oscillation and synchrony) project has investigated which neurons may be responsible for coordinating mPFC-HPC oscillation and synchrony. An integrated probe was developed to implant in rodents to combine optical stimulation and neurophysiological data. The test environment for the rodents was a figure-of-eight maze to probe HPC-mPFC theta coupling in a spatial working memory task. Project members utilised optogenetic manipulation to stimulate and repress mPFC PV neurons. They identified a subset of mPFC PV neurons whose spiking activity varied with the type of opsin activated during stimulation. Overall, the data suggests that mPFC interneurons control mPFC activity during HPC oscillation and synchrony but not its timing. NEURODYNAMICS has developed protocols and collected relevant data on higher brain activities on how functionally connected brain areas cooperate and communicate. Diagnostic tools will be the next step for greater understanding of brain function and corresponding dysfunction.
Keywords
Cognition, neuromodulators, hippocampus, medial prefrontal cortex, parvalbumin, NEURODYNAMICS