Micro-magnetic stimulation of primary visual cortex induces focal and sustained activation of secondary visual cortex
Abstract
Cortical visual prostheses that aim to restore sight to the blind require the ability to create neural activity in the visual cortex. Electric stimulation delivered via microelectrodes implanted in the primary visual cortex (V1) has been the most common approach, although conventional electrodes may not effectively confine activation to focal regions and thus the acuity they create may be limited. Magnetic stimulation from microcoils confines activation to single cortical columns of V1 and thus may prove to be more effective than conventional microelectrodes, but the ability of microcoils to drive synaptic connections has not been explored. Here, we show that magnetic stimulation of V1 using microcoils induces spatially confined activation in the secondary visual cortex (V2) in mouse brain slices. Single-loop microcoils were fabricated using platinum–iridium flat microwires, and their effectiveness was evaluated using calcium imaging and compared with that of monopolar and bipolar electrodes. Our results show that compared to the electrodes, the microcoils better confined activation to a small region in V1. In addition, they produced more precise and sustained activation in V2. The finding that microcoil-based stimulation propagates to higher visual centres raises the possibility that complex visual perception, e.g. that requiring sustained synaptic inputs, may be achievable.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 06, 2022
- Source ID
- 10.1098/rsta.2021.0019
Entities
People
- Seung Woo Lee
- Shelley Fried
Organizations
- Congressionally Directed Medical Research Programs
- Harvard Medical School
- National Eye Institute
- National Institute of Neurological Disorders and Stroke