Although BOLD-fMRI is widely used for in-vivo functional brain mapping, there has been continuing interest in the possibility of using MRI to directly detect the neuronal activity. However, previous works failed to reach a clear consensus on that possibility. Here, we proposed a novel method for direct detection and spatial mapping of neuronal activity with temporal resolution on the order of the action-potential duration(4~5ms). We demonstrated its feasibility using an ex-vivo squid axon and an insulated copper-wire in an event-related electrical-stimulation paradigm. The results are very exciting and promising, although the underlying contrast mechanism needs to be elucidated.