Job ID: 95777
PhD in Neuroscience
Position: Ph.D. Student
Deadline: 2 October 2022
Employment Start Date: 2 January 2023
Contract Length: 4 years
City: Quebec
Country: Canada
Institution: Université Laval
Department: Biochemistry, Microbiology and Bio-informatics, Neuroscience Axis, CRCHUQ
Description:
Mechanisms of dendritic integration and plasticity in GABAergic inhibitory interneurons.
Dendrites, the tree-like neuronal extensions, receive and analyze information from thousands of synaptic inputs and consume most of the brain energy. Activation of a single synapse on a dendrite may affect the firing behaviour of the neuron and, accordingly, its contribution to network activity and cognitive processes. As dendrites of different types of neurons exhibit a remarkable diversity in structure, it is believed that they are fit for neuronal function. Indeed, depending on the neuron type, dendrites have a distinctive mosaic of expression of synaptic receptors, ion channels, and membrane transporters that may shape dendritic input integration in a highly dynamic manner. But how this may happen in different types of neurons or, in other words, what are the cell type-specific mechanisms responsible for the functional specialization of dendrites, remains largely unknown.
This project aims to establish the functional organization of dendrites in two types of inhibitory interneurons residing in the hippocampus, the parvalbumin- and somatostatin-expressing cells. These cells receive specific excitatory inputs; contribute to the formation of memory engrams but fail in several human neurological and neuropsychiatric disorders including epilepsy, Alzheimer’s disease, schizophrenia, depression, and attention deficit hyperactivity disorder.
Using a combination of patch-clamp electrophysiological recordings, two-photon microscopy, calcium imaging in brain slices in vitro, the PhD students will investigate (1) how dendrites of interneurons generate specific activity patterns associated with spatial learning; and (2) how these dendritic patterns can lead to changes in synaptic strength and interneuron firing output during network oscillations.
This PhD project will provide the successful candidates the opportunity to advance our understanding of the cell type-specific mechanisms of dendritic signaling and their potential role during memory encoding. Ultimately, this research will fill the gap between neuronal diversity, function and animal behaviour, which is essential for our understanding of how the brain works.
The Topolnik lab is part of the Neuroscience Axis of the CRCHUQ at the Faculty of Medicine, and the Dept. of Biochemistry, Microbiology and Bio-informatics at the Faculty of Science and Engineering at Laval University located in the heart of Quebec City. The lab is hosting the NeuroWire platform bringing circuit-minded neuroscientists from all over the world: www.neurowire.ca
The successful PhD candidates will work in a multidisciplinary collaborative laboratory and will be provided with an opportunity to receive training in a range of research techniques including patch-clamp electrophysiology, two-photon calcium imaging, optogenetic manipulations in vitro and in vivo, wireless optophysiological recordings (fiberphotometry, miniscope-based calcium imaging, LFP) in behaving animals, immunohistochemistry, confocal microscopy, neuroanatomy, and electrophysiology and image analysis.
PhD candidates from any country can apply and will receive a special exemption for the tuition fees from the Université Laval that will equalize the tuitions fees between international and Canadian students. Full PhD stipend is available for 4 years full-time studies, and the additional support will be provided by the Faculty of Sciences and Engineering of the Université Laval for the successful completion of every semester and related academic advances (e.g., premiums for a successful PhD exam, poster presentation at the international conference, first-author article publication and others).
References:
The role of inhibitory circuits in hippocampal memory processing.
Topolnik L, Tamboli S.
Nature Rev Neurosci. 2022 Aug;23(8):476-492.
doi:10.1038/s41583-022-00599-0. Epub 2022 May 30. PMID: 35637416.
Non-linear calcium signalling and synaptic plasticity in interneurons.
Topolnik L, Camiré O.
Curr Opin Neurobiol. 2019 Feb;54:98-103.
doi: 10.1016/j.conb.2018.09.006. Epub 2018 Oct 12. PMID: 30321867.
Two-photon Calcium Imaging in Neuronal Dendrites in Brain Slices.
Camiré O, Topolnik L.
J Vis Exp. 2018 Mar 15;(133):56776.
doi: 10.3791/56776. PMID:29608159; PMCID: PMC5931772.
Enthusiastic and motivated candidates who are passionate about conducting multidisciplinary research with a focus on neurophysiology are encouraged to contact Dr Lisa Topolnik to discuss the project in more detail. Please submit applications by email to lisa.topolnik@bcm.ulaval.ca
The application should be sent as a single PDF file containing the following:
- Letter of motivation
- Curriculum vitae and publication list
- Name and email address of two referees that can support your application