A catheter (28) has a distal portion that comprises an electrode unit (22) and an ablation unit (24). A control unit (32) is configured: (i) to receive a preliminary blood pressure value (BPV), (ii) to receive a target excited BPV, (iii) to iteratively: (a) drive the electrode unit to apply an excitatory current to nerve of a renal artery (8), (b) receive a detected excited BPV, and (c) alter a value of a property of the excitatory current, until the detected excited BPV crosses a first threshold, and (iv) subsequently, to iteratively: (d) drive the ablation unit to apply ablating energy to the nerve, (e) subsequently, drive the electrode unit to apply a selected excitatory current to the nerve, and (f) receive a detected ablated BPV, until the detected ablated BPV crosses a second threshold. Other embodiments are also described.