Fig. 1: Components of preclinical fMRI.
From: Advanced preclinical functional magnetic resonance imaging of the brain
a MRI hardware geared for the physiological imaging of different animal species. Data is acquired under task-free conditions, using different types of stimulation, or using optogenetic, chemogenetic, sonogenetic, or pharmacological interventions. b In fMRI, blood oxygen level dependent (BOLD) contrast is generated when increased local neuronal activity results in an increase in cerebral blood volume (CBV), cerebral blood flow (CBF), and cerebral metabolic rate of oxygen (CMRO2). As the hemodynamic response exceeds the increase in oxygen consumption, there is a relative decrease in paramagnetic deoxyhemoglobin (dHb) concentration compared to diamagnetic oxyhemoglobin in the blood vessels. This change in dHb ultimately leads to the recordable BOLD signal. c BOLD signal is recorded using a T2*-weighted GE EPI sequence that can be transformed into maps of focal brain activity and functional connectivity. GE EPI data were acquired for educational purposes using a BioSpec Maxwell 94/17. All Bruker in vivo animal work was approved by the institutional animal care and use committee (IACUC) and local authorities and conducted under a valid study permit (Germany AZ 123456).
