Functional and diffusion tensor magnetic resonance imaging of the sheep brain

Abstract

BackgroundAn ovine model can cast great insight in translational neuroscientific research due to its large brain volume and distinct regional neuroanatomical structures. The present study examined the applicability of brain functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) to sheep using a clinical MR scanner (3 tesla) with a head coil. The blood-oxygenation-level-dependent (BOLD) fMRI was performed on anesthetized sheep during the block-based presentation of external tactile and visual stimuli using gradient echo-planar-imaging (EPI) sequence.ResultsThe individual as well as group-based data processing subsequently showed activation in the eloquent sensorimotor and visual areas. DTI was acquired using 26 differential magnetic gradient directions to derive directional fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values from the brain. White matter tractography was also applied to reveal the macrostructure of the corticospinal tracts and optic radiations.ConclusionsUtilization of fMRI and DTI along with anatomical MRI in the sheep brain could shed light on a broader use of an ovine model in the field of translational neuroscientific research targeting the brain.

Neurosurgical cadaveric and in vivo large animal training models for cranial and spinal approaches and techniques — a systematic review of the current literature

“…2, Fig. 3), functional imaging [8], neurovascular structure [9] as well as sleep homeostasis [10], making it an excellent specimen in translational neuroscience. Cadaveric sheep brains (Fig.…”

The sheep brain: an interesting translational model for functional MRI studies?

“…Current developments are under way in our institution to deliver adapted visual stimuli with dedicated instrumentation (Sonnay et al, 2018). A previous study in sheep (Lee et al, 2015) reported robust visual activation in the primary visual cortex (V1) with BOLD responses around 2%. However, in this previous study, sheep were anesthetized with N-methyl-D-aspartate (NMDA) receptor antagonist, Telazol, in order to precisely avoid alteration of cerebral blood hemodynamic responses due to volatile anesthesia such as ISO.…”

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