Assessment of Excitatory Neurotransmitter Levels in Chronic Epilepsy-Induced Rats

Take a control rat and a chronic epilepsy-induced rat implanted with a guide cannula and an electroencephalogram, or EEG, electrode in the hippocampus.

Epilepsy induction increases excitatory neurotransmitter release, causing ion influx into postsynaptic cells, which generates continuous excitatory potentials. This leads to synchronized bursts of electrical activity, termed seizures, recorded using the electrode.

Insert a microdialysis probe with a semi-permeable membrane into the cannula.

Tether the rat to the cage of an EEG recording system.

Infuse a physiological buffer into the brain tissue via the probe inlet.

Ensure the absence of seizure and collect extracellular fluid via the probe outlet to assess neurotransmitter levels.

An elevated basal level in the epileptic rat indicates an epilepsy-mediated increase.

Infuse a high potassium buffer and recollect samples. 

The increased potassium prolongs neuronal excitability, triggering continuous neurotransmitter release.

A temporary spike in neurotransmitter levels in both the epileptic and control rats indicates a high potassium-induced increase.