The long range goal is to build bridges between brain levels from the biophysical properties of synapses to the function of neural systems using combined experimental and computational approaches. The central issues being addressed are how dendrites integrate synaptic signals in neurons, how neural circuits generate behavior, and how learning and sleep adaptively modify these circuits. Fast-spiking parvalbumin-positive interneurons are the focus of both computational and experimental studies of attention in the visual cortex and dysfunction in schizophrenia. Synapses are explored with Monte Carlo methods (MCell) and brain activity is analyzed with the independent components analysis (ICA).