Animal studies in clinical MRI scanners: A custom setup for combined fMRI and deep-brain stimulation in awake rats

TY - JOUR

T1 - Animal studies in clinical MRI scanners

T2 - A custom setup for combined fMRI and deep-brain stimulation in awake rats

AU - Derksen, Maik

AU - Rhemrev, Valerie

AU - van der Veer, Marijke

AU - Jolink, Linda

AU - Zuidinga, Birte

AU - Mulder, Tosca

AU - Reneman, Liesbeth

AU - Nederveen, Aart

AU - Feenstra, Matthijs

AU - Willuhn, Ingo

AU - Denys, Damiaan

N1 - Copyright © 2021. Published by Elsevier B.V.

PY - 2021/6

Y1 - 2021/6

N2 - BACKGROUND: In humans, functional magnetic resonance imaging (fMRI) cannot be used to its full potential to study the effects of deep-brain stimulation (DBS) on the brain due to safety reasons. Application of DBS in small animals is an alternative, but was hampered by technical limitations thus far.NEW METHOD: We present a novel setup that extends the range of available applications by studying animals in a clinical scanner. We used a 3 T-MRI scanner with a custom-designed receiver coil and a restrainer to measure brain activity in awake rats. DBS electrodes made of silver were used to minimize electromagnetic artifacts. Before scanning, rats were habituated to the restrainer.RESULTS: Using our novel setup, we observed minor DBS-electrode artifacts, which did not interfere with brain-activity measurements significantly. Movement artifacts were also minimal and were not further reduced by restrainer habituation. Bilateral DBS in the dorsal part of the ventral striatum (dVS) resulted in detectable increases in brain activity around the electrodes tips.COMPARISON WITH EXISTING METHODS: This novel setup offers a low-cost alternative to dedicated small-animal scanners. Moreover, it can be implemented in widely available clinical 3 T scanners. Although spatial and temporal resolution was lower than what is achieved in anesthetized rats in high-field small-animal scanners, we obtained scans in awake animals, thus, testing the effects of bilateral DBS of the dVS in a more physiological state.CONCLUSIONS: With this new technical setup, the neurobiological mechanism of action of DBS can be explored in awake, restrained rats in a clinical 3 T-MRI scanner.

AB - BACKGROUND: In humans, functional magnetic resonance imaging (fMRI) cannot be used to its full potential to study the effects of deep-brain stimulation (DBS) on the brain due to safety reasons. Application of DBS in small animals is an alternative, but was hampered by technical limitations thus far.NEW METHOD: We present a novel setup that extends the range of available applications by studying animals in a clinical scanner. We used a 3 T-MRI scanner with a custom-designed receiver coil and a restrainer to measure brain activity in awake rats. DBS electrodes made of silver were used to minimize electromagnetic artifacts. Before scanning, rats were habituated to the restrainer.RESULTS: Using our novel setup, we observed minor DBS-electrode artifacts, which did not interfere with brain-activity measurements significantly. Movement artifacts were also minimal and were not further reduced by restrainer habituation. Bilateral DBS in the dorsal part of the ventral striatum (dVS) resulted in detectable increases in brain activity around the electrodes tips.COMPARISON WITH EXISTING METHODS: This novel setup offers a low-cost alternative to dedicated small-animal scanners. Moreover, it can be implemented in widely available clinical 3 T scanners. Although spatial and temporal resolution was lower than what is achieved in anesthetized rats in high-field small-animal scanners, we obtained scans in awake animals, thus, testing the effects of bilateral DBS of the dVS in a more physiological state.CONCLUSIONS: With this new technical setup, the neurobiological mechanism of action of DBS can be explored in awake, restrained rats in a clinical 3 T-MRI scanner.

U2 - 10.1016/j.jneumeth.2021.109240

DO - 10.1016/j.jneumeth.2021.109240

M3 - Article

C2 - 34097929

SN - 0165-0270

VL - 360

SP - 109240

JO - Journal of Neuroscience Methods

JF - Journal of Neuroscience Methods

ER -