In Vivo Neurophysiology
We study how individual cortical neurons encode sensory stimuli and how sensory representation is affected by behavior. The rodent barrel cortex is an excellent system to study these questions since the individual sensory organs (facial whiskers) are represented by easily identifiable cortical columns. Additionally, our group is part of an international effort to understand human brain function at (sub)cellular resolution.
Sensory processing during behavioral paradigms
During animal behavior, there is a constant interplay between brain areas involved in sensory processing, decision making and motor output. The whisker system is an obvious example of a sensorimotor system where motor output (movement of the sensory organs (i.e. the whiskers)) has to be integrated with incoming sensory information. In turn, the sensorimotor information guides cognitive behaviour. Our research question focusses on the organisational principles of the cortical microcircuit across distinct areas of the sensorimotor system. Techniques used are behavioral training, (in vivo) electrophysiology in awake, behaving animals and post-hoc 3D Neurolucida reconstructions.
Sensory processing in prefrontal cortex
Sensory information can induce shifts in attention and guide decision making and this cognitive behavior critically depends on prefrontal cortex. In this project we study how cognitive behaviour is represented in the prefrontal cortical microcircuit. Techniques used are behavioural training (sensory based decision making), (in vivo) single- and multi-unit electrophysiology in behaving animals and post-hoc 3D Neurolucida reconstructions.
3D reconstruction of labeled neurons
Computer models can be helpful tools to design and direct future experiments and predict possible outcomes. Using 3D reconstructions from in vivo recordings, the first goal is to anatomically reconstruct the cortical column. Then, physiological data will be used to model (and playback) the electrical activity of the cortical column. This project is a collaboration with Marcel Oberlaender and Bert Sakmann from the Max-Planck Institute of Neurobiology, Germany. Techniques used are 3D Neurolucida reconstructions and computer modeling of morphological and physiological properties.
Structure-function relationship of individual neurons in human cortex
Extremely little is known about the morphological and physiological properties of adult human neurons. Together with the labs of Huibert Mansvelder, Idan Segev and Henry Markram, our lab is investigating the relationship between structure and function of individual neurons across all layers in adult human cortex, obtained during resection surgery in the VU medical center (Amsterdam, the Netherlands).
We developed a novel pipeline to handle living brain tissue and preserve resected human brain material for the study of fundamental neurophysiological properties such as passive and active membrane properties, synaptic transmission, spike-timing-dependent (associative) plasticity and action potential back propagation.
Eyal, G., Verhoog M.B., Testa-Silva G., Deitcher Y., Benavides-Piccione R., DeFelipe J., de Kock C.P.J., Mansvelder H.D., Segev I., Human cortical pyramidal neurons: From spines to spikes via models. Front Cell Neurosci 2018, in press.
Mohan H., Gallero-Salas Y., Carta S., Sacramento J., Laurenczy B., Sumanovski L., de Kock C.P.J., Helmchen F., Sachidhanandam S. Sensory representation of an auditory cued tactile stimulus in the posterior parietal cortex of the mouse. Sci Rep. 2018 May 17;8(1):7739. doi: 10.1038/s41598-018-25891-x.
Deitcher Y., Eyal G., Kanari L., Verhoog M.B., Kahou G.A.A., Mansvelder H.D., de Kock C.P.J.*, and Segev I.* Comprehensive morpho-electrotonic analysis shows two distinct classes of L2 and L3 pyramidal neurons in human temporal cortex. Cereb Cortex. 2017 Nov 1;27(11):5398-5414. doi: 10.1093/cercor/bhx226.
Mohan H., de Haan R., Mansvelder H.D., de Kock C.P.J., The Posterior Parietal Cortex as Integrative Hub for Whisker Sensorimotor Information. Neurosci., 2017 Jun 19. pii: S0306-4522(17)30418-9. doi: 10.1016/j.neuroscience.2017.06.020. [Epub ahead of print] Review.