KO mice of α574 and β475, as well as α3 KO heterozygous mice,76 show that each of the three genes in a cluster on chromosome 15 mediates similar effects of nicotine; i.e., the animals show resistance to nicotine-induced seizures, whereas the α5 and α3 subunits mediate both the locomotion-suppressant effects of nicotine and somatic signs of nicotine withdrawal.
