Study on Character of Negative Signals in Rat with Electrical Stimulation

It is basically clear about the well known positive hemodynamic response around the activated cortexes during specific task or stimulation. However, what we know of the negative response is little. Our study concentrated on the response signals in optical imaging in rat cortex during voltage impulse stimulation in hindlimb, and we found the negative response signals out around the positive response cortex. We studied the positive and negative response signals about their spatial and temporal properties, and got some speculation about the origin of negative response signals. Our study could be the important consultation about the study on hemodynamic response signals, especially in intrinsic signals optical imaging study about brain function.