Fig. 6

Optostimulation of LC-ACC projecting fibres facilitates glutamatergic synaptic transmission onto pyramidal cells in the ACC. a Samples showing the morphological and electrophysiological characteristics of a patched pyramidal cell and interneuron (red) in layer III of the ACC, as well as the NAergic projecting fibers from the LC (green), which are optostimulated by 470 nm blue light. Bar equals to 10 μm. b Sample traces showing that the increased frequency of sEPSC from pyramidal cells, by exposure to low frequency (5 Hz) optostimulation, is blocked by β receptor antagonist Propranolol. c Samples traces showing that high frequency (20 Hz) optostimulation induced inward current is blocked by α1 receptor antagonist Prazosin. d (Upper panel) Averaged results showing 5 or 20 Hz optostimulation increases the frequency of the sEPSCs (5 Hz, 225.8 ± 32.2% of baseline; 20 Hz, 259.4 ± 38.7% of baseline. n = 10 neurons in each group), which is blocked by β receptor antagonist Propranolol (5 Hz, 112.2 ± 26.2% of baseline; 20 Hz, 124.3 ± 51.7% of baseline. n = 8 in each group) but not by α1 receptor antagonist Prazosin (5 Hz, 219.9 ± 38.6% of baseline; 20 Hz, 211.1 ± 40.8% of baseline. n = 10 in each group). (Bottom panel) Averaged results showing that 5 or 20 Hz optostimulation do not change the amplitude of the sEPSCs (5 Hz, 120.8 ± 24.4% of baseline; 20 Hz, 106.3 ± 16.5% of baseline. n = 10 in each group), neither do the application of Prazosin (5 Hz, 113.7 ± 13.1% of baseline; 20 Hz, 115.3 ± 17.5% of baseline. n = 10 in each group) nor Propranolol (5 Hz, 112.3 ± 17.3% of baseline; 20 Hz, 110.2 ± 11.2% of baseline. n = 8 in each group). e Averaged results showing that 20 Hz but not 5 Hz (5 Hz, 3.58 ± 0.92 pA, 20 Hz, 18.7 ± 3.45 pA, n = 10 in each group) optostimulation induces inward currents, which is blocked by Prazosin (5 Hz, 0.88 ± 1.43 pA, 20 Hz, − 2.27 ± 1.93 pA, n = 10 in each group) but not by Propranolol (5 Hz, 4.41 ± 2.15 pA, 20 Hz, 17.3 ± 5.61 pA, n = 8 in each group). f-g Sample traces and averaged results showing that exposure to 5 or 20 Hz optostimulation changes neither the frequency or amplitude of the sIPSC (frequency: 5 Hz, 91.9 ± 14.3% of baseline, 20 Hz, 92.2 ± 9.7% of baseline; amplitude: 5 Hz, 100.2 ± 2.5% of baseline, 20 Hz, 101.6 ± 2.6% of baseline) nor the holding current (5 Hz: pre, 115.4 ± 22.4 pA, post, 123.5 ± 25.6 pA; 20 Hz, pre, 106.9 ± 26.5 pA, post, 90.3 ± 20.6 pA) of pyramidal cells. h-i, Sample traces and averaged results showing that exposure to 5 or 20 Hz optostimulation changes neither the frequency or amplitude of the sEPSC (frequency: 5 Hz, 93.5 ± 12.8% of baseline, 20 Hz, 87.9 ± 11.6% of baseline; amplitude: 5 Hz, 105.6 ± 5.3% of baseline, 20 Hz, 103.2 ± 2.2% of baseline) nor the holding current (5 Hz: pre, 7.0 ± 8.3 pA, post, 18.8 ± 12.7 pA; 20 Hz, pre, 9.3 ± 13.1 pA, post, 12.4 ± 12.6 pA) of interneurons. #, P > 0.05; *, P < 0.05; **, P < 0.01; Each is compared with the baseline. Paired t-test