Longchun Wang1, Chaofan Ge, Minghao Wang, Bowen Ji, Zhejun Guo, Xiaolin Wang, Bin Yang, Chengyu Li, Jingquan Liu. 1. National Key Laboratory of Science and Technology on Micro/Nano Fabrication Laboratory, Key Laboratory for Thin Film and Micro fabrication of the Ministry of Education, Collaborative Innovation Center of IFSA, Department of Micro/Nano-electronics, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
Abstract
OBJECTIVE: The combination of optical manipulation of neural activities with electrophysiology recording is a promising technology for discovering mechanisms of brain disorders and mapping brain networks. However, fiber-based optrode is limited by the large size of light source and the winding of optical fiber, which hinders animal's natural movement. Meanwhile, the laser diode (LD)-based optrode restricted to the stimulation-locked artefacts will contaminate neural signal acquired from recording channels. APPROACH: Here, a reformative low-noise optrode with internal grounded shielding layer is proposed to mitigate the stimulus-locked artefacts generated during LDactivation for the application of optogenetics. MAIN RESULTS: The artefact mitigation capacity of grounded shielding was verified via simulation and experiments with transient amplitude of artefacts declined from over 5 mV to approximately 200 µV in-vitro. Meanwhile, the stimulation parameters were used based on previous studies by which neurons were activated without over heating the tissue as characterized by in-vitro studies (the output optical intensity is 823 ± 38 mW mm-2). Furthermore, the microelectrodes were modified with Poly (3, 4-ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT: PSS) to increase the signal recording quality of the optrode. Finally, in-vivo optogenetics experiments were carried in the hippocampus of one mouse and the results showed our low-noise optrode was qualified to achieve high-quality neural recording (signal-to-noise ratio about 13) and specific neuron stimulation simultaneously. SIGNIFICANCE: These results suggest the low-noise optrodes exhibit the ability of manipulating and recording neural dynamics and they are excellent candidates for neuroscience research.
OBJECTIVE: The combination of optical manipulation of neural activities with electrophysiology recording is a promising technology for discovering mechanisms of brain disorders and mapping brain networks. However, fiber-based optrode is limited by the large size of light source and the winding of optical fiber, which hinders animal's natural movement. Meanwhile, the laser diode (LD)-based optrode restricted to the stimulation-locked artefacts will contaminate neural signal acquired from recording channels. APPROACH: Here, a reformative low-noise optrode with internal grounded shielding layer is proposed to mitigate the stimulus-locked artefacts generated during LDactivation for the application of optogenetics. MAIN RESULTS: The artefact mitigation capacity of grounded shielding was verified via simulation and experiments with transient amplitude of artefacts declined from over 5 mV to approximately 200 µV in-vitro. Meanwhile, the stimulation parameters were used based on previous studies by which neurons were activated without over heating the tissue as characterized by in-vitro studies (the output optical intensity is 823 ± 38 mW mm-2). Furthermore, the microelectrodes were modified with Poly (3, 4-ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT: PSS) to increase the signal recording quality of the optrode. Finally, in-vivo optogenetics experiments were carried in the hippocampus of one mouse and the results showed our low-noise optrode was qualified to achieve high-quality neural recording (signal-to-noise ratio about 13) and specific neuron stimulation simultaneously. SIGNIFICANCE: These results suggest the low-noise optrodes exhibit the ability of manipulating and recording neural dynamics and they are excellent candidates for neuroscience research.