Cell-type specific arousal-dependent modulation of thalamic activity in the lateral geniculate nucleus
State dependent thalamocortical activity is important for sensory coding, oscillations and cognition. The lateral geniculate nucleus (LGN) relays visual information to the cortex, but the state dependent spontaneous and visually evoked activity of LGN neurons in awake behaving animals remains controversial. Using a combination of pupillometry, extracellular and intracellular recordings from identified LGN neurons we show that thalamocortical neurons and interneurons are distinctly correlated to arousal forming two complementary coalitions. Intracellular recordings indicated that the membrane potential of LGN TC neurons was tightly correlated to fluctuations in pupil size. Inactivating the corticothalamic feedback to the LGN suppressed the arousal dependency of LGN neurons. Taken together our results show that LGN neuronal membrane potential and action potential output are dynamically linked to arousal dependent brain states in awake mice and this might have important functional implications.