title: In Vivo Voltage-Sensitive Dye Imaging of Subcortical Brain Function.
abstract: The whisker system of rodents is an excellent model to study peripherally evoked neural activity in the brain. Discrete neural modules represent each whisker in the somatosensory cortex ("barrels"), thalamus ("barreloids"), and brain stem ("barrelettes"). Stimulation of a single whisker evokes neural activity sequentially in its corresponding barrelette, barreloid, and barrel. Conventional optical imaging of functional activation in the brain is limited to surface structures such as the cerebral cortex. To access subcortical structures and image sensory-evoked neural activity, we designed a needle-based optical system using gradient-index (GRIN) rod lens. We performed voltage-sensitive dye imaging (VSDi) with GRIN rod lens to visualize neural activity evoked in the thalamic barreloids by deflection of whiskers in vivo. We stimulated several whiskers together to determine the sensitivity of our approach in differentiating between different barreloid responses. We also carried out stimulation of different whiskers at different times. Finally, we used muscimol in the barrel cortex to silence the corticothalamic inputs while imaging in the thalamus. Our results show that it is possible to obtain functional maps of the sensory periphery in deep brain structures such as the thalamic barreloids. Our approach can be broadly applicable to functional imaging of other core brain structures.
authors.affiliation: Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA.
authors.forename: Qinggong
authors.initials: Q
authors.lastname: Tang
authors.affiliation: Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA.|Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201 USA.
authors.forename: Vassiliy
authors.initials: V
authors.lastname: Tsytsarev
authors.affiliation: Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA.
authors.forename: Chia-Pin
authors.initials: CP
authors.lastname: Liang
authors.affiliation: Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201 USA.
authors.forename: Fatih
authors.initials: F
authors.lastname: Akkentli
authors.affiliation: Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201 USA.
authors.forename: Reha S
authors.initials: RS
authors.lastname: Erzurumlu
authors.affiliation: Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000818:Animals; D001933:Brain Stem / Q000502:physiology*; D004396:Coloring Agents; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects / Q000502:physiology*; D005260:Female; D058785:GABA-A Receptor Agonists / Q000494:pharmacology; D007276:Injections, Intraventricular; D008297:Male; D051379:Mice; D009118:Muscimol / Q000494:pharmacology; D013003:Somatosensory Cortex / Q000187:drug effects / Q000502:physiology*; D013238:Stereotaxic Techniques; D013788:Thalamus / Q000502:physiology*; D014738:Vibrissae / Q000502:physiology*; D056969:Voltage-Sensitive Dye Imaging / Q000379:methods*
chemical_list: D004396:Coloring Agents; D058785:GABA-A Receptor Agonists; D009118:Muscimol