Reduction in choline acetyltransferase immunoreactivity but not muscarinic-m2 receptor immunoreactivity in the brainstem of SIDS infants

Abstract

The cholinergic neurotransmitter system is vital for several brainstem functions including cardiorespiratory control and central chemosensitivity. This study has examined aspects of the cholinergic neurotransmitter system in the brainstem of sudden infant death syndrome (SIDS) and control infants. The cellular localisation and the optical density of the immunoreactivity of the cholinergic enzyme choline acetyltransferase (CHAT-IR) and the muscarinic acetylcholine receptor m2 (m2-IR) in the medulla was described in 14 SIDS and 9 control cases. There was a reduction in the number of CHAT-IR neurons in the hypoglossal nucleus (control: 71.2 ± 8.3% vs SIDS: 46.1 ± 5.3%) and the dorsal motor nucl..