Fig. 2: In vivo real-time measurement of brain oxytocin dynamics following exogenous oxytocin administration and optogenetic stimulation of oxytocin neurons.
From: A fluorescent sensor for real-time measurement of extracellular oxytocin dynamics in the brain
a, Schematic illustrating fiber photometry recording of MTRIAOT in the AON. b, Representative trace of the z-scored fluorescence intensity of MTRIAOT following intracerebroventricular (ICV) injection of OT at the indicated doses. The amplitude of the signal is shown as a value normalized against the peak value of the highest dose (norm. z-score). c, Summary of normalized z-score (n = 5 mice). d, Representative traces of z-scores upon stimulation with either 20 µg OT or saline via the indicated administration routes (ICV, intranasal (IN) and intraperitoneal (IP)). e, Summary of peak z-scores (n = 3 mice). f, Schematic illustrating fiber photometry recording of MTRIAOT in the AON upon optogenetic stimulation of OT neurons in the PVN. g, Histological images showing transduction of the indicated gene products (ChRmine–mSca and mSca) in OT-positive neurons in the PVN. Overlaid images of the indicated gene product (magenta), OT staining (green) and DAPI staining (blue) are shown to the left. Magnified images within the dashed rectangles are shown on the right. h, Representative traces of MTRIAOT responses to the light stimuli at the indicated powers recorded in a mouse expressing either ChRmine–mSca or mSca in OT neurons. The period of light stimulation is indicated by the pink-shaded area. i, Summary of area under the curve (AUC) values during light stimulation (n = 5 mice in ChRmine–mSca, n = 3 mice in mSca). j, Summary of rise and decay time constants (n = 5 mice). Scale bars, 200 µm (left) and 20 µm (right) in g. Graphs represent the mean ± s.e.m. (c, e and i) and the mean ± s.d. (j). ***P < 0.001, **P < 0.01, *P < 0.05, NS (c, e and i). Statistics (c, e and i) are summarized in Supplementary Note 2.
