The Dopamine Transporter Is a New Target for Ischemic Stroke

Aims

Dopamine transporter (DAT) can regulate DA homeostasis and has been implicated in many nervous system diseases. Whether DAT is involved in the protection against ischemic stroke is unclear.

Methods

In vivo microdialysis measurements of DA were recorded in the ischemic penumbral area of mice with middle cerebral artery occlusion (MCAO). DAT coding gene, Slc6a3 mutation, and DAT overexpression animals were performed MCAO. Madopar (compound formulation of levodopa) and nomifensine (DA reuptake inhibitor) were administered in MCAO animals. Brain slices were prepared in Slc6a3 mutation or wild-type (WT) animals with MCAO to record miniature excitatory postsynaptic currents (mEPSCs) and miniature inhibitory postsynaptic currents (mIPSCs). The effects of DA and its dopamine-1 receptor (D₁R) antagonists (SCH-23390) on mEPSCs, mIPSCs, and neurons protection were recorded.

Results

MCAO caused a prominent increase in DA. Slc6a3 mutation significantly attenuated the ischemic injury, whereas DAT overexpression aggravated this injury. Both nomifensine and madopar protected against brain injury. Slc6a3 mutation and DA restored the disturbance of mEPSCs and mIPSC, and protected against neuron death, which was abolished by SCH-23390.

Conclusion

DAT inhibition might be explored as a strategy for ischemic stroke prevention. DA and D₁R involve in the restoration of synaptic dysfunction and neuron protection.