Involvement of N-methyl-D-aspartate receptors in the augmenting response in rat neocortex

Abstract

The augmenting response was elicited in the neocortex of anaesthetized rats by 10 Hz stimulation of thalamic nuclei. The N-methyl-aspartate (NMA) antagonists 2-amino-5-phosphonopentanoate or 2-amino-7-phosphonoheptanoate were applied topically to the exposed cortex by replacement of fluid in a small plastic cylinder lying on the pial surface. The antagonists delayed the development of augmentation and hastened its decline. It is suggested that this may indicate the involvement of NMA receptors in the augmenting phenomenon in cortex.