title: Spatial patterns and cell surface clusters in perineuronal nets.
abstract: Perineuronal nets (PNN) ensheath GABAergic and glutamatergic synapses on neuronal cell surface in the central nervous system (CNS), have neuroprotective effect in animal models of Alzheimer disease and regulate synaptic plasticity during development and regeneration. Crucial insights were obtained recently concerning molecular composition and physiological importance of PNN but the microstructure of the network remains largely unstudied. Here we used histochemistry, fluorescent microscopy and quantitative image analysis to study the PNN structure in adult mouse and rat neurons from layers IV and VI of the somatosensory cortex. Vast majority of meshes have quadrangle, pentagon or hexagon shape with mean mesh area of 1.29µm(2) in mouse and 1.44µm(2) in rat neurons. We demonstrate two distinct patterns of chondroitin sulfate distribution within a single mesh - with uniform (nonpolar) and node-enriched (polar) distribution of the Wisteria floribunda agglutinin-positive signal. Vertices of the node-enriched pattern match better with local maxima of chondroitin sulfate density as compared to the uniform pattern. PNN is organized into clusters of meshes with distinct morphologies on the neuronal cell surface. Our findings suggest the role for the PNN microstructure in the synaptic transduction and plasticity.
authors.affiliation: Neuroscience Center, University of Helsinki, Viikinkaari 4, P.O.Box 56, 00790 Helsinki, Finland; Institute of Fundamental Medicine and Biology, Kazan Federal University, K. Marx 74, 420012 Kazan, Tatarstan, Russia.
authors.forename: Nikita
authors.initials: N
authors.lastname: Arnst
authors.affiliation: Interdisciplinary Center for Analytic Microscopy, Kazan Federal University, Parizhskoy Kommuny Str 9, 420021 Kazan, Tatarstan, Russia.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Kuznetsova
authors.affiliation: Neuroscience Center, University of Helsinki, Viikinkaari 4, P.O.Box 56, 00790 Helsinki, Finland.
authors.forename: Nikita
authors.initials: N
authors.lastname: Lipachev
authors.affiliation: Institute of Fundamental Medicine and Biology, Kazan Federal University, K. Marx 74, 420012 Kazan, Tatarstan, Russia.
authors.forename: Nurislam
authors.initials: N
authors.lastname: Shaikhutdinov
authors.affiliation: Institute of Fundamental Medicine and Biology, Kazan Federal University, K. Marx 74, 420012 Kazan, Tatarstan, Russia.
authors.forename: Anastasiya
authors.initials: A
authors.lastname: Melnikova
authors.affiliation: Institute of Fundamental Medicine and Biology, Kazan Federal University, K. Marx 74, 420012 Kazan, Tatarstan, Russia.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Mavlikeev
authors.affiliation: Neuroscience Center, University of Helsinki, Viikinkaari 4, P.O.Box 56, 00790 Helsinki, Finland.
authors.forename: Pavel
authors.initials: P
authors.lastname: Uvarov
authors.affiliation: Institute of Fundamental Medicine and Biology, Kazan Federal University, K. Marx 74, 420012 Kazan, Tatarstan, Russia.
authors.forename: Tatyana V
authors.initials: TV
authors.lastname: Baltina
authors.affiliation: Neuroscience Center, University of Helsinki, Viikinkaari 4, P.O.Box 56, 00790 Helsinki, Finland.
authors.forename: Heikki
authors.initials: H
authors.lastname: Rauvala
authors.affiliation: Interdisciplinary Center for Analytic Microscopy, Kazan Federal University, Parizhskoy Kommuny Str 9, 420021 Kazan, Tatarstan, Russia.
authors.forename: Yuriy N
authors.initials: YN
authors.lastname: Osin
authors.affiliation: Institute of Fundamental Medicine and Biology, Kazan Federal University, K. Marx 74, 420012 Kazan, Tatarstan, Russia.
authors.forename: Andrey P
authors.initials: AP
authors.lastname: Kiyasov
authors.affiliation: Neuroscience Center, University of Helsinki, Viikinkaari 4, P.O.Box 56, 00790 Helsinki, Finland; Institute of Fundamental Medicine and Biology, Kazan Federal University, K. Marx 74, 420012 Kazan, Tatarstan, Russia. Electronic address: paveliev@outlook.com.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Paveliev
mesh_terms: D000818:Animals; D011508:Chondroitin Sulfate Proteoglycans / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D051379:Mice; D009415:Nerve Net / Q000166:cytology* / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D037121:Plant Lectins / Q000378:metabolism; D051381:Rats; D034781:Receptors, N-Acetylglucosamine / Q000378:metabolism; D013003:Somatosensory Cortex / Q000166:cytology* / Q000378:metabolism
chemical_list: D011508:Chondroitin Sulfate Proteoglycans; D037121:Plant Lectins; D034781:Receptors, N-Acetylglucosamine; C040129:wisteria lectin
keywords: Cell surface compartments; Chondroitinsulfate proteoglycans; Extracellular matrix; Perineuronal nets; Somatosensory cortex; Synaptic plasticity