HCN2 modulator-5

Two-electrode voltage clamp measures whole-oocyte membrane current from Xenopus oocytes expressing exogenous ion channels, receptors, or transporters; one intracellular microelectrode senses membrane voltage, and the second injects current so the amplifier can hold the membrane at command voltages while recording the compensating current as the functional readout. The method is suited to Xenopus oocytes because their large size supports microinjection and intracellular electrode impalement, but the large membrane area can limit voltage-clamp speed and accuracy, especially for large or fast currents.

The formalin-induced paw inflammation/nociceptive test is a chemical persistent pain model in rodents in which subcutaneous injection of formalin into the hind paw produces spontaneous nocifensive behaviors such as flinching and licking. The response is classically biphasic, consisting of an early acute phase (Phase I) reflecting direct activation of peripheral nociceptors (particularly C-fiber afferents), followed by a later prolonged phase (Phase II) associated with central sensitization in the spinal dorsal horn driven by sustained afferent input and inflammatory signaling. This model is widely used to evaluate analgesic and anti-inflammatory interventions because it captures both peripheral nociception and central sensitization processes within a single assay system.