Figure 5.

Conductances mediated by NMDA receptors are necessary for the generation of the spike/plateau potentials, whereas Ca²⁺ and Na⁺ conductances have only minor contributions. A, Image of the recorded TC neuron in B–D. The glutamate application site (indicated by asterisk) was 79 μm from the soma and 13 μm from the selected dendrite. B, Application of Cd²⁺ (100 μm) and TTX (1 μm) reduced the glutamate elicited spike/plateau potential by about 20%. C, The spike/plateau potential could be re-initiated by means of stronger glutamate stimulation in the presence of Cd²⁺ and TTX. D, The re-initiated spike/plateau was almost eliminated by 15 μm CPP. E, The application of nimodipine (50 μm) reduced the potential by about 9%, while the addition of CPP removed about 80% of the response obtained in the control condition. F, The application of Ni²⁺ (0.4 mm) reduced the response by about 16%, while the addition of CPP removed about 74% of the response obtained in the control condition. G, At −65 mV, the application of Ni²⁺ (0.4 mm) removed the T-type Ca²⁺ burst without affecting the plateau part of the glutamate elicited response. The data in A–D and in E–G are from different neurons.