DOPAMINE TRANSPORTER (DAT) AND SYNAPTIC VESICLE AMINE TRANSPORTER (VMAT2) GENE-EXPRESSION IN THE SUBSTANTIA-NIGRA OF CONTROL AND PARKINSONS-DISEASE

The cellular expression of DAT mRNA and VMAT2 mRNA was investigated in sections of the human post-mortem substantia nigra in control and Par kinson's disease tissue using in situ hybridisation techniques. Short synthetic oligodeoxynucleotides were used to detect these gene transcr ipts at the cellular level. In the control human nigra, high levels of expression were seen in all sub-divisions of the substantia nigra, es pecially within medial regions. By contrast, the level of expression o f both DAT mRNA and VMAT2 mRNA was markedly reduced in Parkinson's dis ease; these reductions in hybridisation signal were associated with (i ) a marked loss of dopamine-containing cells in the substantia nigra, and (ii) a reduction in both DAT and VMAT2 signal per cell in the rema ining pigmented neurones. These disease-related decreases in the cellu lar abundance of both DAT and VMAT2 gene transcripts in the surviving cells of the parkinsonian nigra may reflect compensatory changes in ca techolamine signalling or may be a consequence of neuronal dysfunction .