Recent advances in gene manipulation and nicotinic acetylcholine receptor biology

Abstract

Pharmacological and immunological methods have been valuable for both identifying some native nicotinic acetylcholine receptor (nAChR) subtypes that exist in vivo and determining the neurobiological and behavioral role of certain nAChR subtypes. However, these approaches suffer from shortage of subtype specific ligands and reliable immunological reagents. Consequently, genetic approaches have been developed to complement earlier approaches to identify native nAChR subtypes and to assess the contribution of nAChRs to brain function and behavior. In this review we describe how assembly partners, knock-in mice and targeted lentiviral re-expression of genes have been utilized to improve our understanding of nAChR neurobiology. In addition, we summarize emerging genetic tools in nAChR research.

Figure 1

Timeline of the emergence of genetic tools in nicotine research. Red indicates a novel transgenic mouse. Blue indicates a novel molecular technique used.

Figure 2

Comparison of transgenic and knock-out/knock-in techniques.

Figure 3

Approximate locations of mutations in knock-in mouse strains. ACh = acetylcholine binding site, C = C-terminus, M1-M4 = transmembrane regions, N = N-terminus, SS = Cysteine residues in the Cys loop. Red areas show the approximate locations of mutations. Numbers refer to knock-in mouse strains: 1 = α3[5], 2 = α4L9’S, 3 = α4L9’A, 4 = α4S248F, 5 = α4T529A, 6 = α6L9’S, 7 = α7L250T, 8 = β2V287L