Figure 5.

I_M modulates thalamic activity modes. (A–F) TC neurons were subjected to a series of hyperpolarizing and depolarizing current steps under current-clamp conditions (±200 pA, 250 ms duration). Recordings show that Ret hyperpolarized the TC neurons, thereby reducing the number of tonic APs and favouring burst-like activity (A–D). Application of XE991 induced opposite effects on the firing pattern (E, F). (G–I) Normalized numbers of APs induced by depolarizing pulses (G, H) and subsequent to hyperpolarizing pulses (rebound burst triggered by a LTS, I). AP sequences typically following a delayed onset of firing (indicated by arrow on C, E and F) were regarded as tonic firing (G). Early firing (see D) was regarded as LTS mediated (H). Data are presented as mean ± SEM. Paired t-test, *P < 0.05, **P < 0.01, ***P < 0.001 versus respective control.