title: A multimodal micro-optrode combining field and single unit recording, multispectral detection and photolabeling capabilities.
abstract: Microelectrodes have been very instrumental and minimally invasive for in vivo functional studies from deep brain structures. However they are limited in the amount of information they provide. Here, we describe a, aluminum-coated, fibre optic-based glass microprobe with multiple electrical and optical detection capabilities while retaining tip dimensions that enable single cell measurements (diameter ≤10 µm). The probe enables optical separation from individual cells in transgenic mice expressing multiple fluorescent proteins in distinct populations of neurons within the same deep brain nucleus. It also enables color conversion of photoswitchable fluorescent proteins, which can be used for post-hoc identification of the recorded cells. While metal coating did not significantly improve the optical separation capabilities of the microprobe, the combination of metal on the outside of the probe and of a hollow core within the fiber yields a microelectrode enabling simultaneous single unit and population field potential recordings. The extended range of functionalities provided by the same microprobe thus opens several avenues for multidimensional structural and functional interrogation of single cells and their surrounding deep within the intact nervous system.
authors.affiliation: Unité de neurosciences cellulaires et moléculaires, Institut universitaire en santé mentale de Québec, Québec, Québec, Canada.
authors.forename: Suzie
authors.initials: S
authors.lastname: Dufour
authors.forename: Guillaume
authors.initials: G
authors.lastname: Lavertu
authors.forename: Sophie
authors.initials: S
authors.lastname: Dufour-Beauséjour
authors.forename: Alexandre
authors.initials: A
authors.lastname: Juneau-Fecteau
authors.forename: Nicole
authors.initials: N
authors.lastname: Calakos
authors.forename: Martin
authors.initials: M
authors.lastname: Deschênes
authors.forename: Réal
authors.initials: R
authors.lastname: Vallée
authors.forename: Yves
authors.initials: Y
authors.lastname: De Koninck
mesh_terms: D000535:Aluminum / Q000737:chemistry; D000818:Animals; D005898:Glass / Q000737:chemistry; D008027:Light; D008164:Luminescent Proteins / Q000737:chemistry / Q000378:metabolism; D008297:Male; D051379:Mice; D008839:Microelectrodes; D015335:Molecular Probes / Q000737:chemistry*; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D055100:Optical Fibers; D051381:Rats; D059010:Single-Cell Analysis / Q000295:instrumentation*; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*; D013194:Staining and Labeling / Q000295:instrumentation*
chemical_list: D008164:Luminescent Proteins; D015335:Molecular Probes; D000535:Aluminum