TABLE 2.
Summary of studies on brain nAChR expression in male and female rodents.
| Method | Animal | Result | References |
| Baseline nAChR expression | |||
| Whole-brain [3H]cytisine binding | Sprague-Dawley rats | ↑ density in female vs. male rat. | Koylu et al., 1997 |
| qPCR | Nicotine-preferring rats | ↑α7 transcript in HPC and Str of males vs. females. n.d. in α4, β2, α5 transcript. | Gozen et al., 2016 |
| Nicotine-induced nAChR expression | |||
| Whole-brain [3H]cytisine following 15 daily injections (0.6 mg/kg) | Sprague-Dawley rats | Males: ↑ binding following chronic nicotine. Females: n.d. following chronic nicotine. | Koylu et al., 1997 |
| Half-brain [3H]epibatidine binding following IVSA | Sprague-Dawley rats | n.d. | Donny et al., 2000 |
| [3H]epibatidine binding following CPP (0.4 mg/kg) | Sprague-Dawley rats | Males: ↑ density in caudate. Females: ↑ density in NAc core and shell. | Lenoir et al., 2015 |
| qPCR following nicotine 2-bottle choice | Nicotine-preferring rats | ↑α4 and β2 transcript in hippocampus of males vs. females. | Gozen et al., 2016 |
| qPCR following chronic nicotine (minipump) | Wistar rats | Males: ↑α7 transcript in IPN. Females: ↑α5 transcript in IPN. | Correa et al., 2019 |
| Fluorescence following CPP (0.5 mg/kg) | α4-mCherry X α6-GFP mice | No effect of sex in α4* or α6α4* upregulation. | Akers et al., 2020 |
CPP, conditioned place preference; HPC, hippocampus; IVSA, intravenous self-administration; Str, striatum; VMD, ventral midbrain; n.d., no difference. * indicates additional subunits in the nAChR.