Rattractor-Instant guidance of a rat into a virtual cage using the deep brain stimulation

Naoki Sudo; Sei-Etsu Fujiwara; Takashi Isoyama; Osamu Fukayama

doi:10.1371/journal.pone.0287033

Rattractor-Instant guidance of a rat into a virtual cage using the deep brain stimulation

PLoS One. 2023 Jun 14;18(6):e0287033. doi: 10.1371/journal.pone.0287033. eCollection 2023.

Authors

Naoki Sudo¹, Sei-Etsu Fujiwara², Takashi Isoyama^{1

3}, Osamu Fukayama^{1

4}

Affiliations

¹ Graduate School of Medicine, The University of Tokyo, Bunkyo, Tokyo, Japan.
² St. Marrianna University, School of Medicine, Kawasaki, Kanagawa, Japan.
³ Faculty of Health Sciences, Kyorin University, Mitaka, Tokyo, Japan.
⁴ Center for Information and Neural Networks, Advanced ICT Research Institute, National Institute of Information and Communications Technology, Suita, Osaka, Japan.

Abstract

We developed "Rattractor" (rat attractor), a system to apply electrical stimuli to the deep brain of a rat as it stays in a specified region or a virtual cage to demonstrate an instant electrophysiological feedback guidance for animals. Two wire electrodes were implanted in the brains of nine rats. The electrodes targeted the medial forebrain bundle (MFB), which is a part of the reward system in the deep brain. Following the recovery period, the rats were placed in a plain field where they could move freely, but wired to a stimulation circuit. An image sensor installed over the field detected the subject's position, which triggered the stimulator such that the rat remained within the virtual cage. We conducted a behavioral experiment to evaluate the sojourn ratio of rats residing in the region. Thereafter, a histological analysis of the rat brain was performed to confirm the position of the stimulation sites in the brain. Seven rats survived the surgery and the recovery period without technical failures such as connector breaks. We observed that three of them tended to stay in the virtual cage during stimulation, and this effect was maintained for two weeks. Histological analysis revealed that the electrode tips were correctly placed in the MFB region of the rats. The other four subjects showed no apparent preference for the virtual cage. In these rats, we did not find electrode tips in the MFB, or could not determine their positions. Almost half of the rats tended to remain inside the virtual cage when position-related reward stimuli were triggered in the MFB region. Notably, our system did not require previous training or sequential interventions to affect the behavioral preferences of subjects. This process is similar to the situation in which sheep are chased by a shepherd dog in the desired direction.

Copyright: © 2023 Sudo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Brain
Cardiac Electrophysiology
Deep Brain Stimulation*
Dogs
Electric Wiring
Electricity
Rats
Sheep

Grants and funding

OF was supported by Japan Society of the Promotion of the Science Kakenhi for Young Researchers (B) 17K17684 and Precise Measurement Technology Foundation. SF was supported by St. Marianna University School of Medicine Grant to Promote Diversity in Research SMUGDIVR20192. There was no additional external funding received for this study. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.