(RS)-AMPA ((±)-AMPA) monohydrate is a glutamate analogue and a potent and selective excitatory neurotransmitter L-glutamic acid agonist. (RS)-AMPA monohydrate does not interfere with binding sites for kainic acid or NMDA receptors[1][2].
(RS)-AMPA monohydrate (10-3-10-4 M) causes depolarizations of cultured rat spinal and brainstem neurones. The depolarization by (RS)-AMPA monohydrate is clearly dose-dependent, although there is a great variability of effects between individual neurones. Application of (RS)-AMPA monohydrate at 10-5 M produces only small depolarizations (3-7 mV), whereas at 10-4 M, the amplitudes of the depolarizations ranged from 4 to 33 mV. (RS)-AMPA monohydrate also causes an increase of the discharge rate of spontaneously firing neurones or sometimes evoked a short burst of action potentials in silent cells. (RS)-AMPA monohydrate exerts its depolarizing effects by activating glutamate/quisqualate receptors without affecting NMDA receptors[1].
[1]. HÖsli L, et al. Effects of the glutamate analogue AMPA and its interaction with antagonists on cultured rat spinal and brain stem neurones. Neurosci Lett. 1983 Mar 28;36(1):59-62.
[2]. Sommer B, et al. Flip and flop: a cell-specific functional switch in glutamate-operated channels of the CNS. Science. 1990 Sep 28;249(4976):1580-5.