Single unit-derived connectivity networks in tuberous sclerosis complex reveal propensity for network hypersynchrony driven by tuber-tuber interactions

Network hypersynchrony is emerging as an important system-level mechanism underlying seizures, as well as cognitive and behavioural impairments, in children with structural brain abnormalities. We investigated patterns of single neuron action potential behaviour in 206 neurons recorded from tubers, transmantle tails of tubers and normal looking cortex in 3 children with tuberous sclerosis. The patterns of neuronal firing on a neuron-by-neuron (autocorrelation) basis did not reveal any differences as a function of anatomy. However, at the level of functional networks (cross-correlation), there is a much larger propensity towards hypersynchrony of tuber-tuber neurons than in neurons from any other anatomical site. This suggests that tubers are the primary drivers of adverse outcomes in children with tuberous sclerosis.