Extended Data Fig. 9: LHb-driven, 5HT1AR mediated, recurrent feedforward modulation of 5-HT firing activity in the DRN.
From: Nonlinear recurrent inhibition through facilitating serotonin release in the raphe
a, Schematic of experimental design. Left, AAV-ChR2(H134R)-mCherry is injected into the LHb. Right, whole-cell recordings from TdT-positive 5-HT neurons. b, LHb-driven heterosynaptic 5HT1AR-mediated potential in SERT-TdT 5-HT neuron. c, Spiking of a 5-HT neuron in response to a 2.5 s current step (scale, 20 mV, 500 ms). Below, raster plot of the same 5-HT neuron spiking. d, Spiking of a 5-HT neuron in response to a 2.5 s current step with LED activation of ChR2-expressing LHb terminals in the slice for 1 sec in the middle of the current step. Below, raster plot of the same 5-HT neuron spiking. e, Spiking of a 5-HT neuron in response to a 2.5 s current step in the presence of WAY 100-635. Below, raster plot of the same 5-HT neuron spiking. f, In the presence of WAY 100-635, spiking of a 5-HT neuron in response to a 2.5 s current step with LED activation of ChR2-expressing LHb terminals in the slice for 1 sec in the middle of the current step. Below, raster plot of the same 5-HT neuron spiking. g, Instantaneous frequency line (top) and spike count histogram plots (below) from recording in c (mean +- SEM). h, Instantaneous frequency line (top) and spike count histogram plots (below) from recording in d (mean +- SEM). i, Instantaneous frequency line (top) and spike count histogram plots (below) from recording in e (mean +- SEM). j, Instantaneous frequency line (top) and spike count histogram plots (below) from recording in f (mean +- SE). k, Instantaneous frequency population plot in pre- and post-WAY recordings with LED stimulation (n = 3 neurons, mean +- SEM). l, Cumulative frequency population plot in pre- and post-WAY recordings with LED stimulation (3 cells, p = 0.0017, two-sided Kolmogorov-Smirnov test). m, Instantaneous frequency population plot in pre- and post-WAY recordings in the absence of LED stimulation (n = 3 neurons, mean +- SEM). n, Cumulative frequency population plot in pre- and post-WAY recordings in the absence of LED stimulation (3 cells, p = 0.07, two-sided Kolmogorov-Smirnov test).
