| Type | MGI:General | Description | unlike wild-type mice, homozygotes exhibit severe bradycardia, as shown by an increased mean R-R interval at rest bradycardia is reduced during enhanced spontaneous physical activity, and abolished after block of cardiac muscarinic receptors by atropine however, bradycardia persists after methoxamine treatment, as R-R intervals are increased in both mutant and wild-type mice to similar extents |
