Evidence will be presented for depolarized axons in spontaneously active nociceptors in neuropathic pain patients (microneurography), a finding that is in line with the facilitating role of depolarization and increased membrane resistance for spontaneous depolarizing fluctuations presented by Dr. Walters. Tests for axonal excitability of skin nociceptors in pig and humans will be shown for different profiles of slow depolarizing electrical stimuli that may be used to test for local hyperexcitability and enhancement of membrane resistance, and potentially for the presence of spontaneous depolarizing fluctuations. Such observations may predict success of local analgesic treatment. The closely related role of cooling on nociceptor excitability will be presented leading to an alternative explanation of cold allodynia. Implications and limitations of evoked sensory tests to probe nociceptor excitability under normal conditions and in neuropathic pain will be discussed.