A multimodality investigation of cerebral haemodynamics and autoregulation in phMRI
Gozzi A, Reese T, Schwarz A, Ceolin L, Bertani S, Bifone A
Centre of Excellence for Drug Discovery, Psychiatry, GlaxoSmithKline
Pharmacological MRI methods are used to assess central effects of acute drug challenge, but many psychoactive drugs also induce peripheral blood pressure (BP) changes, potentially introducing confounds. We examined BP along with cerebral blood volume (CBV), measured by MRI, and laser-Doppler flow (LDF) changes induced by norepinephrine, a non-brain penetrant vasopressor not expected to elicit changes in neuronal activity. Blood flow autoregulation was preserved over a wide BP range (80-140 mmHg); CBV changes were also non-significant within this range. Above the upper BP threshold, measurable changes in both CBV and LDF were observed, particularly localised in cortical structures.