Figure 2.

Manipulating NGF affects desensitization of currents induced by α,β-meATP. A, Representative examples of currents induced by applications of α,β-meATP (black bar) in control condition (left), after anti-NGF antibody treatment (middle), and after NGF treatment (right). Traces of 10 μm α,β-meATP-evoked currents recorded after a second agonist application (30 s interval; see arrows) are superimposed. Note the differential recovery from desensitization in the three conditions. B, Histograms show no change in the time constant values of the α,β-meATP-evoked current decay, used as an index of desensitization onset (τ_fast; n = 151, n = 56, and n = 46 for control, anti-NGF, and NGF, respectively). C, Histograms show that anti-NGF treatment reduces recovery (*p < 0.0001) from desensitization of P2X₃-mediated currents, whereas NGF increases (*p < 0.001) this value (n = 99, n = 49, and n = 38 for control, anti-NGF, and NGF, respectively). D, Representative traces of Ca²⁺ transients show that, with paired α,β-meATP application (black dots, 30 s spaced), the second response is more depressed after anti-NGF treatment than in control. Neurons are identified by their responsiveness to KCl (50 mm, 1 s), which remains unchanged after anti-NGF treatment. E, Histograms showing the depressant action of anti-NGF treatment on the amplitude of Ca²⁺ transients induced by 10 μm α,β-meATP or 50 mm KCl. Control level is indicated by a dashed line. *p ≤ 0.05; n = 4–5 experiments (30–40 cells in each experiment).