Fig. 4. PACAP^PBL→DR axon terminal activation produces panic-like symptoms but does not create conditioned fear memory.

a, Schematic and histological confirmation of Cre-dependent expression of ChR2 in the PBL of an Adcyap1^Cre/+ mouse for optogenetic activation of PACAP^PBL→DR axon terminals. Scale bars: 100 µm. This experiment was repeated on four mice with similar results. b, Schematic of optical conditioning test. c–e Immobility levels during the conditioning (c), context (d), and cue tests (e). n = 4 mice per group. Laser activation is indicated by blue shading. f, Schematic of the real-time place aversion test. g,h, Heat map (g), and time spent in stimulation-paired and unpaired chambers (h, unpaired two-sided t-test, P = 0.0008). n = 4 mice per group. i,j, Breathing (i) and heart rate (j) and corresponding AUC analyses during PACAP^PBL→DR axon terminal activation (5 sec) at various photostimulation frequencies. AUCs were subtracted from the AUC of the no-stimulation period. n = 4 mice per group. Data are presented as the mean ± SEM; see also Supplementary Table 3 for statistical details. ***P<0.001.