Fig. 1
From: Optogenetic activation of serotonergic neurons changes masticatory movement in freely moving mice
Optogenetic activation of DRN 5-HT neurons during voluntary mastication alters muscle activity patterns. (a) Schematic illustration of the position of the optical fiber stereotaxically inserted into the DRN of double transgenic mice expressing ChR2 in central 5-HT neurons for DRN 5-HT neuron activation. (b) Representative images showing Tph2-IR neurons (Alexa Fluor 594, red), YFP-IR neurons (Alexa Fluor 488, green) indicating ChR2 (C128S) expression, and the merged image in DRN. Scale bars = 300 μm. The dashed white lines indicate optic fiber placement. (c) and (d) Representative EMG recordings of digastric and masseter muscles during voluntary mastication before and after blue light application (470 nm; blue bar) for optogenetic activation of DRN 5-HT neurons as activation (c, top), or yellow light application (590 nm; yellow bar) as control (d, top). Expanding EMG recordings picked from top EMG recordings (dotted box outlines); before and after light application are indicated at the bottom in c and d. DRN dorsal raphe nucleus, EMG electromyography, IR immunoreactive.
