Figure 2.

Effect of deletion or partial deletion of the α4 and/or β2 nAChR subunits on response to chronic nicotine treatment measured by immunoprecipitation. nAChR binding sites were measured by quantitative immunoprecipitation of [³H]epibatidine binding sites by anti‐α4, anti‐β2 or anti‐α5 antibodies in whole brain extracts for α4⁺⁺, β2⁺⁺, α4⁺⁻, β2⁺⁻, α4⁺⁻/β2⁺⁻, α4⁻⁻ or β2⁻⁻for mice that had been chronically treated with saline, 0.25, 1.0 or 4.0 mg·kg⁻¹·h⁻¹ nicotine for 10 days. Points are the mean ± SEM for the number of mice indicated in the following table. Numbers are presented as number α4 antibody, number β2 antibody, number α5 antibody.

Nicotine dose	α4++	β2++	α4+−	β2+−	α4+−/β2+−	α4−−	β2−−
Saline	7,7,7	6,7,5	8,7,6	7,7,6	8,8,8	6,6,6	5,5,5
0.25 mg·kg−1·h−1	7,7,7	6,5,5	8,9,8	6,6,6	6,6,6	6,6,6	6,7,7
1.0 mg·kg−1·h−1	6,7,5	5,6,5	9,9,7	7,7,6	8,8,8	8,8,5	7,7,7
4.0 mg·kg−1·h−1	7,8,6	6,6,5	8,9,7	7,6,6	7,7,7	7,7,7	5,5,5