Hemodynamics Under Pharmacological Challenge in Rat Brain: Comparison of BOLD, CBV and CBF Using Bicuculline

Zeenat Atcha¹, Hui Chien Tay¹, Fatima Ali Nasrallah¹, Huang Wei Wei¹, Brian Henry², Kai-Hsiang Chuang¹

The aim of our study was to investigate the sensitivity and distinct spatiotemporal responses of bicuculine-induced brain activity using three pharmacological magnetic resonance imaging (phMRI) methods: blood-oxygen-level-dependent (BOLD) contrast, cerebral blood volume (CBV) with intravascular contrast agent, and cerebral blood flow (CBF) with arterial spin labeling (ASL). Acute administration of bicuculline produced region-specific hemodynamic responses in the S1, hippocampal, caudate putamen and thalamus regions. Furthermore, we demonstrate that temporal dynamics of CBV and BOLD signals were long lasting, whereas CBF responses were immediate. Information obtained from these complementary imaging techniques provide better insights to underpin neurovascular coupling upon a drug challenge.