Fig. 5.

Pharmacology of the tectothalamic response. Blocking inhibitory IC input reveals a robust NMDA current elicited from the ICc. (A) In this experiment, two MGB neurons were recorded simultaneously in response to photostimulation in the IC, as shown in a photomontage of the slice. (B and C) Mean evoked currents. Traces are shown in Fig. S3. Cell 1 received robust inhibitory input from the external shell of the IC (ICs), whereas cell 2 received both inhibitory ICs input and excitatory ICc input (Left). Bath application of GABA receptor antagonists eliminates the IPSCs, while revealing large EPSCs in the ICc (Center). These large EPSCs are eliminated following bath application of NMDA antagonists, leaving the AMPA-mediated EPSCs in cell 2 unaffected (Right).