Figure 3.

WIN and AM1241 activate Ca²⁺-permeable, nonselective currents in subsets of TG neurons. A, Application of indicated concentrations of AM1241 (AM), WIN, MO, and CAP trigger [Ca²⁺]_i accumulation in subset of TG neurons. Numbers of analyzed (numerator) and total recorded (denominator) neurons are indicated within bars. CAP was applied for 1 min, whereas MO, WIN, and AM1241 were applied for 3 min. B, Characteristic Ca²⁺-imaging traces from n = 10 TG neurons that responded to both AM1241 and WIN. Application durations are noted by horizontal bars. C, Typical whole-cell fast and slow inward currents in TG neurons generated by AM1241 (30 μm), WIN (25 μm), and ACEA (25 μm). The currents were acquired from separate neurons bathed in SES (2 mm Ca²⁺) (see Materials and Methods for buffer compositions). D, Concentration–response curves for I_WIN, I_ACEA, and I_AM1241. Data for each point were generated from separate neurons by application of cannabinoids for 2 min. n = 6–18. Whole-cell recordings were performed with SES and SIS. E, I–V relationships (averaged from 4–8 traces) for I_AM1241, I_WIN, and I_ACEA were obtained by recording from neurons maintained in a Mg²⁺-free SES physiological solution with 2 mm Ca²⁺. The electrodes were filled with Cs-containing SIS without Mg²⁺. I–V curves were recorded from separate neurons. Depolarizing voltage ramp protocol is presented in the inset. TG neurons were cultured for 24–48 h. Error bars are SEM. **p < 0.01.