Kainic acid is a selective agonist of kainate receptor [1].

Kainate receptor is an ionotropic receptor that responds to glutamate. Presynaptic kainate receptor modulates GABA release and is involved in inhibitory neurotransmission. Postsynaptic kainate receptor is involved in excitatory neurotransmission.

In aged rats, kainic acid significantly reduced the latency to full clonic-tonic seizures and increased the amount of seizures rats. Also, kainic acid significantly increased the release of norepinephrine (NE), ASP and GLU in aged rats with clonic-tonic seizures [1]. In neonatal rats, intrahippocampal injection of kainic acid (1 μg) significantly induced pyramidal cell death [2]. In adult rats, kainic acid significantly increased the mRNA levels of neurotrophin-4/5 (NT-4/5) in the dorsal horn and in the spinal cord white matter, and increased the mRNA level of brain-derived neurotrophic factor (BDNF) in the ventral horn. While kainic acid didn’t affect neurotrophin-3 (NT-3). These results suggested that NT-4/5 and BDNF participated in the response of the spinal cord to excitotoxic stimuli induced by kainic acid [3].

References:
[1].  Dawson R Jr, Wallace DR. Kainic acid-induced seizures in aged rats: neurochemical correlates. Brain Res Bull, 1992, 29(3-4): 459-468.
[2].  Cook TM, Crutcher KA. Intrahippocampal injection of kainic acid produces significant pyramidal cell loss in neonatal rats. Neuroscience, 1986, 18(1): 79-92.
[3].  Scarisbrick IA, Isackson PJ, Windebank AJ. Differential expression of brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4/5 in the adult rat spinal cord: regulation by the glutamate receptor agonist kainic acid. J Neurosci, 1999, 19(18): 7757-7769.