Figure 5.

Culturing the α3β2 AChR cell line at 29°C increases the population of functional AChRs similar to overnight incubation in Nic. (A) A family of representative currents is shown for the concentration-response relationship for α3β2 cells that were placed at 29°C for at least 6 h and as long as 48 h. For comparison, currents recorded from cells that were incubated in Nic (100 μM) overnight are also shown (Wang et al. 1998). (B) The sensitivity to activation by ACh for the cells grown at reduced temperature were identical to those that had been incubated overnight in 100 μM Nic. The full concentration/response for both conditions is also shown. Responses were normalized to the response peak measured for 300 μM ACh for each cell. The EC₅₀ for each condition was 202 ± 14 μM for cells grown at 29°C (□) and was 209 ± 26 μM for cells incubated overnight in Nic (▪). (C) Representative currents are shown for IMR-32 cells that were incubated overnight in Nic (100 μM). The responses to 300 μM ACh and 300 μM Cyt are nearly identical to currents recorded from naive IMR-32 cells (Fig. 1 A, inset).