Using Ca2+ and voltage-sensitive dye imaging technique,previous studies have shown wave-like propagation of neuronal activities in the retina and cortex.Retinal waves are found in neonatal animals and may contribute to the development of the visual system.Cortical waves have been observed in many brain areas and in a variety of brain states,and may contribute to the processing and storage of information.Here we report that entrainment of membrane potential oscillation of cortical neurons by visually evoked cortical waves may underlie long-range contextual modulation of visual perception.In the primary visual cortex (V1) of anaesthetized adult rats,in vivo whole-cell recording from two distant cortical neurons revealed long-range propagation of cortical waves,either occurring spontaneously or evoked by visual stimulation.