Chunk #10 — Activation of metabotropic glutamate receptors (mGluRs) or muscarinic Ach receptors (mAchRs) induces rhythmic bursting at α/θ frequencies in TC neurons
when TC neurons are relatively depolarized (≥~−60 mV), a brief injection of positive current leads to tonic firing or single spike activity (i.e. tonic or relay mode, see below) (Fig. 1A, top right) (Llinás and Jahnsen 1982). The discovery of these two modes of firing has laid the foundation for several basic ideas regarding how the thalamus operates with broad agreement existing that LTCPs are mainly associated with low frequency oscillations during sleep and anaesthesia (McCarley et al. 1983; Domich et al. 1986; Nunez et al. 1992; Steriade et al. 1993; Crunelli et al. 2006; but see Sherman 2001) whereas tonic firing occurs more commonly during wakefulness and is important for the faithful relay of sensory information to the neocortex.
