EN
Higher order posteromedial thalamic nucleus of the rat (PoM) receives cholinergic (Ach) and noradrenergic (NA) neuromodulatory projections originating from the brain stem. With a whole-cell patch-clamp method we investigated influence of these neuromodulators on membrane potential of PoM neurons in the thalamic slices. Ach (carbachol) or NA (norepinephrine) agonists were added to the bath to mimic the activation of appropriate neuromodulatory system. Both agonists induced slow depolarization of membrane potential by about 9 mV. However, carbachol but not norepinephrine substantially enhanced amplitude of membrane potential fluctuations in the frequency range from 8 to 500 Hz (reaching more than two-fold elevation between 25–180 Hz). These carbachol induced fluctuations were not blocked neither by manual membrane repolarization to the control level, nor by the blockage of GABA-A receptors. Our results suggest that this increase of fluctuation strength might result mainly from activation of muscarinic receptors. This research and SN were supported by the European Union Regional Development Fund through the Foundation for Polish Science within the frames of International PhD Program in Neurobiology.