MUSCARINIC ACETYLCHOLINE-RECEPTOR SUBTYPE MESSENGER-RNAS IN THE HUMANAND RAT VESTIBULAR PERIPHERY

The expression of the five muscarinic acetylcholine receptor (mAChR) s ubtypes (m1-m5) in the vestibular end-organs and in the primary affere nt vestibular ganglia of the human and rat was studied using RT-PCR fr om the two tissue populations from both species. In the human, althoug h all five mAChR subtypes were expressed in brain, only the mt, m2, an d m5 mAChR subtypes were amplified from both the vestibular ganglia an d the vestibular end-organs, while in the rat, all five mAChR subtypes were expressed. These data suggest that the efferent cholinergic axo- dendritic and axe-somatic synapses have a muscarinic component and tha t there are pharmacologic implications for patients with vestibular dy sfunction. (C) 1996 Academic Press Limited