Table 1.
Summary of studies on DA, nACh and 5-HTT genetics related to nicotine and cognition Genetic studies related to cognitive effects of nicotine
| Gene (polymorphism) | Cognitive measures | Sample | Finding |
|---|---|---|---|
| DAT (VNTR) | Morris watermaze (mouse) | Variable depending on dose | KO + low dose nicotine → ↑locomotor effects KO + high dose nicotine →↓locomotor effects Weiss et al., 2007 |
| DAT (VNTR) | Kiddie-Sads-Present and Lifetime Version | 305 adolescents | 10 repeat + prenatal nicotine → ↑ hyperactivity (males only) Becker at al., 2008 |
| ANKK1 (rs1800497) | EEG activation | 67 female smokers | Taq A1 + depression or nicotine → ↑ EEG deactivation Gilbert et al., 2004 |
| ANKK1 (rs1800497) | ERP during go-nogo task | 62 heavy smokers 26 nonsmokers |
Taq A1 + acute nicotine →↑nogo P3 Taq A1 + deprived nicotine →↓nogo P3 Evans et al., 2009 |
| DRD2 (rs6277) | Auditory n-back task | 22 regular smokers 14 nonsmokers |
T-carriers + nicotine patch →↓ attention/working memory Jacobsen et al., 2006 |
| DRD4 (VNTR) | Stroop task | 31 current smokers 17 ex-smokers |
Past nicotine use + 7≥ repeats → ↓ selective attention and processing speed Munafo and Johnstone 2008 |
| COMT rs4680 | Visual N-back working memory task | 36 healthy smokers | Val homozygous+ nicotine →↓ attention/working memory Loughead et al., 2008 |
| α7 | 5-choice serial reaction-time test of sustained attention (mouse) |
Variable | WT + nicotine →↑sustained attention KO →↓ sustained attention Young et al., 2004 |
| α7 | Morris watermaze (rat) | 6 aON* 7 saline 9 aON-controls |
aON treated →↓ spatial learning ability Curzon et al., 2006 |
| α7 and β2 | Radial-arm maze (mouse) | 16 WT 6 β2 KO 10α7 KO |
β2 KO or α7 KO →↓ spatial learning ability β2 KO →↓ nicotine consumption relative to wildtype mice (short term) α7 KO →↓ nicotine consumption relative to wildtype mice (long term) |
| β2 | Morris watermaze and passive avoidance test (mouse) |
8 KO 8 WT |
KO mice + nicotine → no associative memory enhancement Picciotto et al., 1995 |
| β2 | M-diameter circular open-field exploratory behavior (mouse) |
15 KO 20 WT |
KO + chronic nicotine →↑ exploratory behavior and spontaneous rearing to the level of WT Besson et al., 2008 |
| β2 | Y maze (mouse) | 7 WT 10 KO 9 KO + VEC# |
KO →↓ sensory processing KO + VEC →↑ normalizes sensory processing to WT level Maskos et al., 2005 |
| SLC6A4 (5-HTTLPR) | Spatial working memory task | 64 smoking deprived habitual smokers |
S allele + nicotine replacement → ↑ Spatial working memory Carolson et al., 2009 |
*
aON= antisense oligonucleotide (aON) targeted toward the 3′- and 5′-UTR coding regions of the rat α7nAChR
#
eGFP bi-cistronic vector