The role of glial glutamate transporter in the baseline synaptic response and short-term synaptic plasticity of CA1 area of the hippocampus in male Wistar rat

Background. Glial cells release different gliotransmitters and response to neurotransmitters released from neurons. These cells especially astrocytes, having different transporters, play an important role in synaptic space homeostasis and synaptic plasticity. In this study, the role of hippocampal glial glutamate transporter (EAAT2) in baseline synaptic response and short term synaptic plasticity were investigated.

Methods. In this experimental study, ceftriaxone, EAAT2 activator (0.5mmol/0.5μl), was microinjected intrahippcampally for activation of hippocampal glial glutamate transporter in male wistar rats. Baseline synaptic response and short term synaptic plasticity were evaluated by field potential recording. fEPSP was recorded from CA1 following Schaffer collaterals stimulation. After Input/Output curve construction, short term synaptic plasticity was induced by paired pulse stimulations.

Results. Activation of EAAT2 by ceftriaxone microinjection in CA1 did not have any effect on baseline synaptic response (P> 0.05, Two Way ANOVA). There was no significant difference in Paired Pulse Index at 20, 80, and 200 ms inter-pulse interval between ceftriaxone treated and control group (P> 0.05, Two Way ANOVA).

Conclusion. The results suggest that hippocampal glial glutamate transporter activation does not have effect on baseline synaptic response and short term synaptic plasticity in CA1 area of the hippocampus.

Practical implications. Considering the role of glial cells in regulating the excitability of the nervous system as well as synaptic plasticity, correcting these features of the nervous system by manipulating glial cells can help the treatment or prevention of neurological diseases. In this study, the role of glial cells in the homeostasis of the glutamate in the synaptic space of the hippocampus was evaluated, through the stimulation of its uptake, on the basic synaptic activity and short-term synaptic plasticity.