Normal apoptosis levels in mice expressing one alpha 7 nicotinic receptor null and one L250T mutant allele

The alpha 7 nicotinic receptor (nAChR) is a ligand-gated ion channel mediating cholinergic transmission throughout the nervous system. To further characterize the function of this receptor, we generated mice expressing the alpha 7 L250T nAChR mutation and demonstrated that homozygous (T/T) L250T mice die within 24h of birth and display extensive apoptosis and abnormal layering within their cortex. We now demonstrate that mice with one alpha 7 null and one L250T allele (-/T) show little apoptosis and normal development of their cortex yet exhibit the same lethal phenotype as T/T mice. Furthermore, L250T mice show normal levels of apoptosis in other nervous system regions expressing alpha 7 nAChRs. These results suggest that apoptosis is not the cause of death for L250T neonatal mice.