Imaging brain activity during seizures in freely behaving rats using a miniature multi-modal imaging system

Iliya Sigal; Margaret M Koletar; Dene Ringuette; Raanan Gad; Melanie Jeffrey; Peter L Carlen; Bojana Stefanovic; Ofer Levi

doi:10.1364/BOE.7.003596

Imaging brain activity during seizures in freely behaving rats using a miniature multi-modal imaging system

Biomed Opt Express. 2016 Aug 22;7(9):3596-3609. doi: 10.1364/BOE.7.003596. eCollection 2016 Sep 1.

Authors

Iliya Sigal¹, Margaret M Koletar², Dene Ringuette³, Raanan Gad¹, Melanie Jeffrey⁴, Peter L Carlen⁵, Bojana Stefanovic⁶, Ofer Levi¹

Affiliations

¹ Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, ON M5S 3G9, Canada; The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, 10 King's College Road, Toronto, ON M5S 3G4, Canada.
² Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada.
³ Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, ON M5S 3G9, Canada.
⁴ Krembil Research Institute, 60 Leonard Avenue, Toronto, ON M5T 2S1, Canada.
⁵ Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, ON M5S 3G9, Canada; Krembil Research Institute, 60 Leonard Avenue, Toronto, ON M5T 2S1, Canada.
⁶ Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Medical Biophysics, University of Toronto, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada.

Abstract

We report on a miniature label-free imaging system for monitoring brain blood flow and blood oxygenation changes in awake, freely behaving rats. The device, weighing 15 grams, enables imaging in a ∼ 2 × 2 mm field of view with 4.4 μm lateral resolution and 1 - 8 Hz temporal sampling rate. The imaging is performed through a chronically-implanted cranial window that remains optically clear between 2 to > 6 weeks after the craniotomy. This imaging method is well suited for longitudinal studies of chronic models of brain diseases and disorders. In this work, it is applied to monitoring neurovascular coupling during drug-induced absence-like seizures 6 weeks following the craniotomy.

Keywords: (110.6150) Speckle imaging; (110.7348) Wavefront encoding; (170.0180) Microscopy; (170.1470) Blood or tissue constituent monitoring; (170.2655) Functional monitoring and imaging; (170.5380) Physiology.