Axons are the anatomical substrate for both the onset and forward distribution of all fast electrical signals in the brain. They encompass all presynaptic terminals for neurotransmitter release and arborize extensively throughout the brain, establishing the anatomical circuitry connecting cells and brain regions. Despite recent advances in structural imaging we still have poor insights into how axon collaterals are functionally organized and how they actively conduct electrical signals along their highly branched morphologies. In the brain the diameters of axons are mostly below ~1.0 μm prohibiting conventional electrical recording. Biophysical analysis predicts that axonal branch points must be highly active domains to allow signal conduction. At present, optical recording approaches based on voltage-sensitive dyes (VSDs) provide the most promising tool available to image voltage transients from small structures and across fields of view simultaneously. Voltage-sensitive dye imaging with single-photon epifluorescence maximizes the number of photons to obtain high temporal resolution information of the AP. Within this FOM Programme Neurophotonics, experts in the field of single-neuron physiology (Kole, Wierenga) join forces with experts in advanced imaging and wavefront shaping technology (Mosk, Vellekoop, Gerritsen, Kapitein). The goal is to develop advanced light-based methodology to unravel the biophysical principles underlying signal generation, propagation and dispersion in axons embedded in functional circuits in the neocortex. The studies will be performed in close collaboration with the Biophysics group (UU) led by Lukas Kapitein focusing on super-resolution and the NanoLINX group led by Allard Mosk (UU) focusing on light-shaping.
For this PhD project wave-front shaping technologies will be developed under direct supervision of Dr. Marko Popovic, in collaboration with the FOM consortium 16NEPH01. The optical recordings will be applied to study the in vitro action potential initiation and propagation optically at unprecedented temporal and spatial resolution. You will work with living brain tissue harvested from rodents, learn and extend state-of-the-art epifluorescence imaging techniques. To isolate individual axons you will develop in collaboration with physicists new light patterning methods based on computer-generated holography to manipulate the light in the Fourier space using a Liquid Crystal on Silicon-Spatial Light Modulator (LCOS-SLM). This will enable to pattern the excitation light in three dimensions. With this holographic illumination approach the advantages of epifluorescence methods will be preserved, while reducing the light interference from the neighboring structures. You will record spatially separated voltage signals, for example from nodes of Ranvier, internodes and axonal collaterals and compare these to conventional electrical recordings. With these new avenues you will expand the fundamental basis of axon physiology research and improve existing computational models.
The work will take place in the FOM workgroup and Axonal Signaling group led by Prof.dr. M.H.P. Kole. We are an enthusiastic multidisciplinary team investigating axons in health and disease and are based at the Netherlands Institute for Neuroscience (Nederlands Herseninstituut), a research institute of the Royal Netherlands Academy of Arts and Sciences (KNAW) located in Amsterdam. Our group is also part of the Cell Biology Department at the Utrecht University.
We are looking for a creative physicist or biologist with a MSc degree and a strong affinity towards optics and microscopy and/or cellular neuroscience/electrophysiology. As this project relies heavily on the development and implementation of light shaping techniques, prior experience and knowledge of optical imaging techniques (epifluorescence, two-photon or functional confocal imaging) are critical. Furthermore, experience with different levels of neurosciences (molecular, cellular, network approaches applied either in vitro as well as in vivo) are considered advantageous. Critical scientific thinking, communication skills and English proficiency will be a part of the assessment during the interview. Selected candidates will give a presentation of their internships.
Conditions of employment
When fulfilling a PhD position at NWO-I, you will get the status of junior scientist. You will have an employee status and can participate in all the employee benefits NWO-I offers. You will get a contract for four years. Your salary will be up to a maximum of 2,834 euro gross per month. The salary is supplemented with a holiday allowance of 8 percent and an end-of-year bonus of 8.33 percent. You are supposed to have a thesis finished at the end of your four year term with NWO-I. A training programme is part of the agreement. You and your supervisor will make up a plan for the additional education and supervising that you specifically need. This plan also defines which teaching activities you will be responsible (up to a maximum of ten percent of your time). The conditions of employment of NWO-I are laid down in the Collective Labour Agreement for Research Centres (Cao-Onderzoekinstellingen), more exclusive information is available at this website under Personeelsinformatie (in Dutch) or under Personnel (in English). General information about working at NWO-I can be found in the English part of this website under Personnel. The 'Job interview code' applies to this position.
Please upload a motivation letter, CV and the contact details of two references.
30 June 2017.