FIG. 7.
Persistent activity in GIN cells following trains of extracellular stimuli was not blocked by pharmacological blockade of fast synaptic transmission, but was blocked by the metabotropic glutamate receptor 1a (mGluR1a) antagonist LY367385. A: persistent activity in a GIN cell in normal ACSF. B: persistent activity in the same cell after washing on d-2-amino-5-phosphonovaleric acid (APV, 50 μM), 6,7-dinitroquinoxaline-2,3(1H,4H)-dione (DNQX, 20 μM), and picrotoxin (PTX, 20 μM) for 15 min. Note that the inhibitory period that typically followed the stimulus under normal conditions (A) was eliminated by application of these blockers (B). Scale bar for A also applies to B. C: persistent activity in a GIN cell in normal ACSF (stimulus train presented at arrow above trace). D: membrane depolarization and persistent firing were blocked by the application of LY367385 (200 μM). E: membrane depolarization and persistent firing returned on washout of LY367385. Scale bar for D also applies to C and E. Dotted line in all panels indicates baseline membrane potential.