We have published two new papers examining population activity in the visual cortex.
In a first study, published in Nature Neuroscience, we used optogenetics to activate neural populations during visual stimulation. We found that visual circuits respond to population activation by precisely adjusting their level of excitation and inhibition, depending upon sensory conditions.
In a second study, published in Neuron, we show that neural population activity can predict single neuron synaptic activity, down to millisecond timescales. In the awake brain, population activity is particularly informative about synaptic inhibition.