Localization of noradrenaline transporter mRNA expression in the human locus coeruleus

The distribution of the noradrenaline transporter mRNA was examined in the human dorsolateral pontine tegmentum, using in situ hybridization histochemistry with 35S-labeled oligonucleotide probes. Analysis of film autoradiograms showed that noradrenaline transporter mRNA was expressed through the whole extent of the locus coeruleus complex. The largest population of labeled cells was seen in the nucleus locus coeruleus proper whereas few scattered labeled cells were visualized in its ventral subdivision, namely the locus subcoeruleus area. Thus, these anatomical findings suggest that cells expressing noradrenaline transporter mRNA in the human brainstem are predominantly, if not exclusively, concentrated within areas known to contain the largest collections of noradrenergic neurons.