Effect of local dendritic application of UCL1684 on dendritic excitability. A, Somatic (bottom) and dendritic (top; 690 μm from the soma) responses to dendritic current injections (middle) in control (black) and after local dendritic UCL1684 (purple). B, Average number of AP bursts during dendritic current injections of different amplitude (control: black; dendritic UCL1684: purple; dendritic recording 640–750 μm from the soma; n = 9). C, Average number of bursts during dendritic current injection (1.5 nA) in control (black) and after dendritic UCL1684 (purple; n = 9). D, Average, normalized dendritic voltage integral during AP trains at different frequencies (lines represent sigmoidal fits, control: black, dendritic UCL1684: purple; dendritic recording 640–750 μm from the soma; n = 9). E, Average critical frequency in control (black) and after dendritic UCL1684 (purple; n = 9).