• Synaptic mechanisms of information processing during sleep and waking

    The brain switches its filters for sensory information when going from waking to sleep. Sleep rhythm generators are crucial for this switch. We want to know more about the types of information processed by these day-and-night-working brain areas and how they are modulated by arousal. Therefore, we focus on one of the main sleep rhythm generators: the Thalamic Reticular Nucleus (TRN). The TRN is a GABAergic nucleus that has inhibitory control over the thalamus, but its filtering roles are still obscure.

    The aim of this project is to identify novel afferents to the TRN to bring insight into unknown functions of this strategically positioned nucleus. Our tracing experiments show fine-tuned, highly local and divergent trajectories onto and within the TRN. We combine anatomical techniques using immunostainings and tracers with in vitro/in vivo electrophysiology and optogenetic stimulations.

    Immunohistochemical labeling of postsubicular afferents (red) into thalamic areas, notably into TRN (green, immunostaining for parvalbumin) and burst discharge of TRN cells elicited through optogenetic activation of subicular-TRN synapses with blue light.
  • Dynamics of sleep states – and their role in arousability

    Just as much as wakefulness, sleep is a vigilance state with a variable behavioral output. For example, our alarm clock wakes us up most of the time, but occasionally we might not hear it. Therefore, sleep is not a uniform state and its functions may change from one moment to the next.

    Recently, we asked:

    • What changes sleep’s vulnerability to noise?
    • How do the brain and periphery act together to make sleep non-uniform?
    • How is non-uniformity in sleep affected in diseases that affect sleep quality?
    Variable behavioral response of a slepeing mouse to noise: wake-up or sleep-through

    We follow sleep using conventional polysomnographic or local field potential recordings, as well as electrocardiography. Optogenetic techniques are used to silence specific brain areas during sleep to elucidate their role in arousability. We will also explore whether highlighted signatures are aberrant in mouse models of sleep, cardiovascular or metabolic disorders.