A transient increase in cortical neuronal activity is followed by a transient increase in cerebral blood flow. This physiological process of neurovascular coupling, measured by its hemodynamic response function (HRF), is used to infer neuronal activity in modern vascular-based brain imaging techniques. Nevertheless, brain pathology may alter the HRF confounding the interpretation of imaging studies. Our aim was to investigate the extent of HRF alterations after a minimally injuring transient global cerebral ischemia (GCI) in adult male Wistar rats (n=11). We introduced a new technique of measuring HRF by taking advantage of the whole-brain discontinuous EEG burst-suppression (BS) state induced by a chloral-hydrate overdose (400 mg/kg BW i.p.). We tested the changes in HRF at 48 hours after a 5-minute GCI induced using a variation of the “4-vessel occlusion model”. Simultaneous cortical electroencephalographic (EEG) activity and Laser Doppler (LD) signal were recorded from the left hemisphere. The rectified EEG was convoluted with a prototype HRF to obtain a synthetic LD signal. Two parameters of the prototype HRF (peak response latency and response width) were then programmatically optimized to attain a maximum correlation between the recorded and the synthetic LD signals within the 0.1-0.4 Hz band. The HRF was found to depend on the depth of BS anaesthesia. With decreasing bursting frequency there was a progressive increase of HRF latency (time to HRF peak) that could be reasonably described by a linear regression. The slope of the relationship was similar prior to and after GCI. Nevertheless, the Y-intercept was about double after GCI (F=81, P<0.01). The delayed hemodynamic response after GCI could not be attributed either to cardio-vascular changes (heart rate remained normal) or to changes in electrical activity patterns (intra-burst EEG was similar to that during anaesthetic coma). Our data suggest that the process of neurovascular coupling itself remains delayed for days after a brief global cerebral ischemia.