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Updated: May 8, 2026

In vivo Optogenetic Stimulation of the Rodent Central Nervous System
Published on: January 15, 2015
In-vivo optogenetic manipulation approach for gerbil medial nucleus of trapezoid body
Purpose:
This study introduces an in-vivo optogenetic manipulation approach for the medial nucleus of the trapezoid body (MNTB) in Mongolian gerbils, a species with a hearing range similar to humans. The MNTB is crucial for sound localization, but traditional methods lack temporal precision and reversibility. The aim of this study is to develop a specific, reversible method for controlling MNTB activity with fast and precise temporal control, an approach vital for studying sound localization.
Methods:
We stereotactically injected adeno-associated viral vectors encoding opsins into the gerbil MNTB. Precise targeting was achieved despite the MNTB's location in a deep, heavily myelinated area of the brainstem. Opsin expression was confirmed via confocal microscopy. In-vivo electrophysiology combined with optical stimulation was used to test optical activation and suppression of MNTB activity during sound stimuli.
Results:
Opsin expression was strong and stable in MNTB neurons over weeks and months. Laser stimulation during in-vivo recordings successfully induced both activation and suppression of MNTB neurons, demonstrating fast and precise control over neural activity.
Conclusion:
This in-vivo optogenetic method provides specific, reversible control of MNTB activity in gerbils with rapid, real-time modulation. It offers a powerful tool for investigating sound localization and auditory processing with high temporal precision.

