Simultaneously changes in striatum dopaminergic and glutamatergic parameters following hypoxic-ischemic neuronal injury in newborn piglets.

Basal ganglia injury (BGI) is a type of perinatal hypoxic-ischemic (H-I) brain injury. Both malfunctions of glutamatergic and dopaminergic pathways in striatum were suggested to contribute to BGI. In current study, we investigated the imaging profile of glutamate (Glx) levels by proton magnetic resonance spectroscopy ((1)H-MRS), and the expression of dopamine D2 receptors (D2R) and dopamine transporter (DAT) by immunohistochemical staining in a newborn piglet model of H-I brain injury. We found that the number of striatal D2R positive neurons decreased following H-I brain injury, and the decrease in positive neuron number was consistent with the degree of striatum. Following H-I brain insult, the number of striatal DAT positive neurons and glutamate level were simultaneously increased initially, followed by a gradual decline toward control level. There was a positive correlation between the changes in striatal DAT positive neurons and glutamate level following H-I brain insults in newborn piglets. Our findings suggest that following H-I brain insult, striatal D2R positive neurons decreased due to neuron death; straital DAT initially increased to compensate for dopamine uptake; and glutamatergic and dopaminergic systems in striatum may act in an interdependent way in the striatum of newborn piglets.