Kainic acid

Kainic acid is the prototypic, selective kainate receptor (KAR) agonist. Analog of L-Glutamate.

Kainic acid is a potent excitant and neurotoxin (shows ~30-fold more neurotoxic potency than L-Glutamate).

It induces various changes in vivo including recurrent seizures, behavioural changes, oxidative stress, glial activation and selective neuronal death.

Kainic acid exerts its neuroexcitatory action by binding to glutamate receptors to cause Ca²⁺ influx and triggering subsequent excitotoxic neuronal death pathway cascades.

It is widely used to model various neurodegenerative diseases and epilepsy.

The kainate receptor (KAR) agonist kainic acid induces neuronal oscillations in the gamma frequency band (35-100Hz). KAR activation leads to synchronous activity of excitatory and inhibitory network firing. Kainic acid is commonly used at concentrations of 400-600 nM to induce oscillations in acute brain slices. At a concentration of 550 nM, kainic acid from Hello Bio induces a strong gamma frequency neuronal oscillation (approx. 35Hz) within the CA3 region of the rat hippocampus (see Fig 1 above). Oscillations were abolished following kainic acid washout.

#Protocol 1: Oscillations assay

• Acute rat hippocampal slices were placed in an interface chamber and held at 30°C with a glass recording electrode placed in the CA3 region of the hippocampus.
• Control basal activity was recorded for 1 hr in the presence of aCSF before continuous perfusion of aCSF containing kainic acid at 550nM to induce oscillations.
• Oscillation activity was recorded once oscillations had stabilised (~2-3 hours). 
• Kainic acid was then washed out and replaced with control aCSF. 
• Data were analysed to create a power spectrum of the oscillation.