Mapping cortical networks
How do neurons in the cortex share information? The cortex is richly interconnected, and while fMRI studies have shown that distant brain areas are fluidly coupled, we don't know how these dynamics are achieved on a cellular level. We recorded from individual cells while imaging activity across the dorsal cortex to determine the functional coupling of individual neurons to activity in global cortical networks. This revealed that a change in behavioural state driven by locomotion reconfigures how individual neurons participate in distributed cortical ensembles.
How does a network control itself? Brain-machine interfaces are not only promising for neurological applications, but also powerful for investigating neuronal ensemble dynamics during learning. Optical readouts of brain activity enable us to non-invasively monitor the local network while animals learn a BMI task to understand how volitional control of a network is achieved. We trained mice to operantly control an auditory cursor using spike-related calcium signals recorded with two-photon imaging in motor and somatosensory cortex. See Nature Neuroscience News and Views
Unlearning chronic pain
The power of the brain lies in its ability to learn, and it retains this capacity throughout adulthood. Yet this very ability is the basis for many neurological diseases. Pathological states can be learned by the network: for example, elevated activity learned by various pain pathways result in chronic pain sensation, even in the absence of noxious stimuli. But what can be learned can be unlearned. This proposal of a novel therapy was awarded the Regeneron Prize for Innovation in Biomedicine for utilizing the brain’s endogenous capacity for learning to re-train healthy function in neuropathic pain disorders.
What predicts a neuron's firing probability? Stimulus-evoked response probability correlated strongly with spontaneous firing rate, but weakly with tuning properties, indicating a spectrum of inherent responsiveness across pyramidal cells. Neurons projecting to higher cortical areas differed in whisker tuning and responsiveness, and carried different amounts of stimulus information. Read more here and here.
Optical blood oxygenation monitor
Sudden Unexpected Death in Epilepsy (SUDEP) is a devastating risk for seizure sufferers, and the leading cause of death in patients with refractory epilepsy. While there is no single underlying cause in all SUDEP cases, hypoxia is of particular interest, and this intervention has implications for a wide range of disorders. Read more here.