Julia Schiemann | Systems Neurophysiology | ZHMB Lab

To tackle these important systems neuroscience questions on the cellular, the network and the behavioural level, we will combine in vivo electrophysiology and imaging during active motor behaviour of mice with targeted optogenetic manipulations in defined brain circuits.

In vivo single cell recordings and labeling

To characterise the firing activity of neurons in the intact brain in vivo, we perform extracellular single cell recordings. To identify specific subtypes of noradrenaline and dopamine neurons within diverse networks individually recorded neurons are juxtacellularly labeled and immunohistochemically defined.

Extracellular action potential recording trace and histology image of an identified dopamine neuron in the substantia nigra.

In vivo patch clamp recordings

Intracellular whole-cell patch clamp recordings in awake mice reveal membrane potential dynamics and synaptic input – spike output transformations of individual neurons during active behaviour.

In vivo patch clamp recording trace showing action potentials and subthreshold activity of a pyramidal neuron in the motor cortex. For subtype and projection target identification the morphology of patched neurons can be reconstructed.

Behaviour, optogenetics and pharmacology

To study movement control under physiological and pathophysiological conditions (mimicking Parkinson’s disease) we currently establish a quantitative behavioural paradigm for mice. To decipher how identified cell populations and brain circuits shape (motor) behaviour, network activity will be manipulated in vivo using virus-based optogenetic strategies and selective pharmacology.

Schematic illustrating virus injections and optogenetic network pertubations

Confocal and slide scanner microscopy

For single cell identification and expression analysis (of e.g. ion channels, transcription factors), viral circuit mapping and whole-brain connectivity maps we employ multi-labelling fluorescence immunohistochemistry, confocal and slide scanner microscopy.

Microscopy images of pyramidal neurons in the motor cortex