Table 1. Neurotransmitter abnormalities in the brainstem in SIDS.
Adapted with permission from [96].
a.5-HT:5-hydroxytryptamine;b.ChAT:acetylcholine transferase;c.DMX: dorsal motor nucleus of the vagus; d.H.G.:hypoglossal nucleus; e.C.A.:catecholamines; f.VLM:ventrolateralmedulla;g.PNMT:phenylethanolamineN-methyltransferase; h.NTS: nucleus of the solitary tract;i.T.H: tyrosine hydroxylase;j.N.A: nucleus ambiguous; k.ICC: immunocytochemistry; l.NMDA: N-methyl-D-aspartic acid; SIDS: Sudden infant death syndrome
Substance | Effective findings |
5-HTa | There were observed overall decreases in 5-HT1A binding, 5-HT cell proliferation, and proportionate decreases in 5-HTT [21] binding. Immunostaining of 5-HT1A and 5-HT2A receptors reveals an increase in the periaqueductal grey matter; a 5-HT rise in raphe obscures (HPLC: high-pressure liquid chromatography) was observed [80,81]. |
ChATb | Lowering in ChAT immunostaining in DMXc and HGd [82]. |
Muscarinic receptor | A decrease in binding to the arcuate nucleus with a limited number of immunopositive neurons for muscarinic receptors in the arcuate nucleus is observed, but this has little impact on the arcuate nucleus's muscarinic receptor immunostaining [82-84]. |
C.A.e | No abnormal α2-adrenergic receptor binding was observed [85], so although dendritic spines in C.A. neurons increased in VLMf [86]: PNMTg immunoreactivity was absent in NTSh[87], T.H.i immunostaining was reduced in VLM and DMX [88], and T.H. immunostaining was not correlated with the number of T.H.- immunostained neurons in DMX, NTS, NAj, or VLM [89]. |
α2-adrenergic receptor | Decreased α-2A receptors by ICCk in VLM & NTS [90]. |
NMDAl receptor | Six medulla nuclei had higher levels of NR1 subunit mRNA, higher levels of NR1 protein in DMX, and lower levels of NR1 protein in the spinal trigeminal nucleus [83]. |
Kainate receptor | Reduced binding in arcuate nucleus [91]. |
Substance P | Increased immunostaining in trigeminal fibres, higher immunostaining in NTS and spinal trigeminal nucleus, increased immunostaining in medulla homogenates, and no differences in binding in medulla [92- 95] |