1
|
Víg L, Zátonyi A, Csernyus B, Horváth ÁC, Bojtár M, Kele P, Madarász M, Rózsa B, Fürjes P, Hermann P, Hakkel O, Péter L, Fekete Z. Optically Controlled Drug Delivery Through Microscale Brain-Machine Interfaces Using Integrated Upconverting Nanoparticles. SENSORS (BASEL, SWITZERLAND) 2024; 24:7987. [PMID: 39771721 PMCID: PMC11680031 DOI: 10.3390/s24247987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2024] [Revised: 12/11/2024] [Accepted: 12/12/2024] [Indexed: 01/11/2025]
Abstract
The aim of this work is to incorporate lanthanide-cored upconversion nanoparticles (UCNP) into the surface of microengineered biomedical implants to create a spatially controlled and optically releasable model drug delivery device in an integrated fashion. Our approach enables silicone-based microelectrocorticography (ECoG) implants holding platinum/iridium recording sites to serve as a stable host of UCNPs. Nanoparticles excitable in the near-infrared (lower energy) regime and emitting visible (higher energy) light are utilized in a study. With the upconverted higher energy photons, we demonstrate the induction of photochemical (cleaving) reactions that enable the local release of specific dyes as a model system near the implant. The modified ECoG electrodes can be implanted in brain tissue to act as an uncaging system that releases small amounts of substance while simultaneously measuring the evoked neural response upon light activation. In this paper, several technological challenges like the surface modification of UCNPs, the immobilization of particles on the implantable platform, and measuring the stability of integrated UCNPs in in vitro and in vivo conditions are addressed in detail. Besides the chemical, mechanical, and optical characterization of the ready-to-use devices, the effect of nanoparticles on the original electrophysiological function is also evaluated. The results confirm that silicone-based brain-machine interfaces can be efficiently complemented with UCNPs to facilitate local model drug release.
Collapse
|
2
|
Judák L, Dobos G, Ócsai K, Báthory E, Szebik H, Tarján B, Maák P, Szadai Z, Takács I, Chiovini B, Lőrincz T, Szepesi Á, Roska B, Szalay G, Rózsa B. Moculus: an immersive virtual reality system for mice incorporating stereo vision. Nat Methods 2024:10.1038/s41592-024-02554-6. [PMID: 39668210 DOI: 10.1038/s41592-024-02554-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 10/29/2024] [Indexed: 12/14/2024]
Abstract
Due to technical roadblocks, it is unclear how visual circuits represent multiple features or how behaviorally relevant representations are selected for long-term memory. Here we developed Moculus, a head-mounted virtual reality platform for mice that covers the entire visual field, and allows binocular depth perception and full visual immersion. This controllable environment, with three-dimensional (3D) corridors and 3D objects, in combination with 3D acousto-optical imaging, affords rapid visual learning and the uncovering of circuit substrates in one measurement session. Both the control and reinforcement-associated visual cue coding neuronal assemblies are transiently expanded by reinforcement feedback to near-saturation levels. This increases computational capability and allows competition among assemblies that encode behaviorally relevant information. The coding assemblies form partially orthogonal and overlapping clusters centered around hub cells with higher and earlier ramp-like responses, as well as locally increased functional connectivity.
Collapse
|
3
|
Juhász G, Madarász M, Szmola B, Fedor FZ, Balogh-Lantos Z, Szabó Á, Rózsa B, Fekete Z. Hippocampal recording with a soft microelectrode array in a cranial window imaging scheme: a validation study. Sci Rep 2024; 14:24585. [PMID: 39427030 PMCID: PMC11490575 DOI: 10.1038/s41598-024-75170-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 10/03/2024] [Indexed: 10/21/2024] Open
Abstract
The hippocampus has a crucial role in the formation, consolidation and recall of memories as well as in navigation related processes. These functions are in the focus of neuroscience and different disciplines have contributed to this research field for decades. Two-photon imaging in awake animals is a valuable new aspect for these observations, especially when it is supported by electrophysiology. In this study, we applied high speed two-photon hippocampal imaging through a chronically implanted, soft, transparent microelectrode (STM) device incorporated into a cranial window chamber in awake mice. We monitored the impedance of the recording sites over the course of the experiments to observe long-term changes in recording quality. The large-scale ipsilateral local field potential (LFP) recordings from the dorsal hippocampus provided reliable sharp wave-ripples (SPW-Rs), multi-unit activity (MUA) and single-unit activity (SUA) for up to two months. Calcium imaging of GCaMP6f. labeled cells from the CA1 pyramidal layer under the transparent device was possible even after six months in thy1-GCaMP6f. transgenic mice. We investigated the immune response with GFAP staining after the end of the long-term experiments. Based on our results, this dedicated transparent electrode device proved to be suitable for simultaneous two-photon imaging and large-scale electrophysiological measurements in chronic experiments in mice.
Collapse
|
4
|
Pantl O, Chiovini B, Szalay G, Turczel G, Kovács E, Mucsi Z, Rózsa B, Cseri L. Seeing and Cleaving: Turn-Off Fluorophore Uncaging and Its Application in Hydrogel Photopatterning and Traceable Neurotransmitter Photocages. ACS APPLIED MATERIALS & INTERFACES 2024; 16. [PMID: 39368105 PMCID: PMC11492179 DOI: 10.1021/acsami.4c10861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2024] [Revised: 09/24/2024] [Accepted: 09/24/2024] [Indexed: 10/07/2024]
Abstract
The advancements in targeted drug release and experimental neuroscience have amplified the scientific interest in photolabile protecting groups (PPGs) and photouncaging. The growing need for the detection of uncaging events has led to the development of reporters with fluorescence turn-on upon uncaging. In contrast, fluorescent tags with turn-off properties have been drastically underexplored, although there are applications where they would be sought after. In this work, a rhodamine-based fluorescent tag is developed with signal turn-off following photouncaging. One-photon photolysis experiments reveal a ready loss of red fluorescence signal upon UV (365 nm) irradiation, while no significant change is observed in control experiments in the absence of PPG or with irradiation around the absorption maximum of the fluorophore (595 nm). The two-photon photolysis of the turn-off fluorescent tag is explored in hydrogel photolithography experiments. The hydrogel-bound tag enables the power-, dwell time-, and wavelength-dependent construction of intricate patterns and gradients. Finally, a prominent caged neurotransmitter (MNI-Glu) is modified with the fluorescent tag, resulting in the glutamate precursor named as GlutaTrace with fluorescence traceability and turn-off upon photouncaging. GlutaTrace is successfully applied for the visualization of glutamate precursor distribution following capillary microinjection and for the selective excitation of neurons in a mouse brain model.
Collapse
|
5
|
Kokas B, Krizsány G, Pekli D, Meltzer A, Bárdos D, Rózsa B, Bibok A, Korda D, Somogyi D, Doros A, Budai A, Halász J, Werling K, Hagymási K, Mühl D, Tegze B, Nádasdy-Horváth D, Györke T, Szijártó A, Hahn O. [A new method to enhance liver regeneration: double venous deprivation of the liver]. Orv Hetil 2024; 165:1433-1439. [PMID: 39244743 DOI: 10.1556/650.2024.33122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Accepted: 07/06/2024] [Indexed: 09/10/2024]
Abstract
A májdaganatok reszekálhatóságának feltétele a műtét után megmaradó, megfelelő
májműködést biztosítani képes elégséges májszövetmennyiség. Ennek mérete a műtét
előtt különböző eljárásokkal növelhető meg. A vena (v.) portae occlusiós
technikákkal lassabb és csekélyebb növekedés érhető el, kis rizikójú intervenció
során. Amennyiben a hypertrophia nem elegendő, illetve ha felmerül a gyors
tumorpogresszió lehetősége, úgy alkalmazható a v. portae egyoldali elzárása és a
májállomány kettéválasztása, ami rövid idő alatt a legjelentősebb indukált
hypertrophiát biztosítja. A kombinált műtét morbiditása azonban viszonylag
jelentős. A fenti technikák előnyeit hivatott ötvözni a máj kettős vénás
elsorvasztása, melynek során az azonos oldali v. portae és v. hepatica
occlusiója történik. Ezzel gyors, az utóbbi módszert megközelítő mértékű
ellenoldali lebeny-hypertrophia érhető el biztonságosan. Esetünkön keresztül ezt
a májhipertrofizáló technikát mutatjuk be. A 75 éves nőbeteg bizonytalan hasi
panaszai miatt indult kivizsgálása során a máj jobb lebenyében, a középső
szektort is érintő, nagy méretű intrahepaticus cholangiocellularis tumor
igazolódott. Tekintettel a lokalizációra, a tumor csak jobb oldali
trisegmentectomiával volt eltávolítható. Májvolumetriát végeztünk, mely alapján
a megmaradó máj volumene (S1-2-3) 35% alattinak bizonyult. Kettős vénás
depriváció mellett döntöttünk. A jobb v. portae és v. hepatica dextra
occlusióját követő 7. napon jelentős hypertrophiát (41%) igazoltunk. A tervezett
műtétet sikeresen elvégeztük. A posztoperatív szakban enyhe ascites csorgását
konzervatívan kezeltük, egyéb szövődmény nem jelentkezett, a 8. posztoperatív
napon emittáltuk a beteget. Amennyiben a tervezett májreszekció kapcsán a
megmaradó máj várható térfogata nem elégséges, májregenerációs technikák
alkalmazására van szükség. Az elérhető technikák közül a legújabb, alacsony
szövődményrizikóval kecsegető megoldás a kettős vénás depriváció, mely során az
azonos oldali v. portae és v. hepatica elzárására kerül sor. A fenti eset
bizonyítja, hogy a módszertől gyors és hatékony májregeneráció várható minimális
megterheléssel, ami lehetővé teszi a biztonságos kiterjesztett májreszekciók
elvégzését. Orv Hetil. 2024; 165(36): 1433–1439.
Collapse
|
6
|
Csomos A, Madarász M, Turczel G, Cseri L, Bodor A, Matuscsák A, Katona G, Kovács E, Rózsa B, Mucsi Z. A GFP Inspired 8-Methoxyquinoline-Derived Fluorescent Molecular Sensor for the Detection of Zn 2+ by Two-Photon Microscopy. Chemistry 2024; 30:e202400009. [PMID: 38446718 DOI: 10.1002/chem.202400009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 03/02/2024] [Accepted: 03/06/2024] [Indexed: 03/08/2024]
Abstract
An effective, GFP-inspired fluorescent Zn2+ sensor is developed for two-photon microscopy and related biological application that features an 8-methoxyquinoline moiety. Excellent photophysical characteristics including a 37-fold fluorescence enhancement with excitation and emission maxima at 440 nm and 505 nm, respectively, as well as a high two-photon cross-section of 73 GM at 880 nm are reported. Based on the experimental data, the relationship between the structure and properties was elucidated and explained backed up by DFT calculations, particularly the observed PeT phenomenon for the turn-on process. Biological validation and detailed experimental and theoretical characterization of the free and the zinc-bound compounds are presented.
Collapse
|
7
|
Madarász M, Fedor FZ, Fekete Z, Rózsa B. Immunohistological responses in mice implanted with Parylene HT - ITO ECoG devices. Front Neurosci 2023; 17:1209913. [PMID: 37746144 PMCID: PMC10513038 DOI: 10.3389/fnins.2023.1209913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 08/17/2023] [Indexed: 09/26/2023] Open
Abstract
Transparent epidural devices that facilitate the concurrent use of electrophysiology and neuroimaging are arising tools for neuroscience. Testing the biocompatibility and evoked immune response of novel implantable devices is essential to lay down the fundamentals of their extensive application. Here we present an immunohistochemical evaluation of a Parylene HT/indium-tin oxide (ITO) based electrocorticography (ECoG) device, and provide long-term biocompatibility data at three chronic implantation lengths. We implanted Parylene HT/ITO ECoG devices epidurally in 5 mice and evaluated the evoked astroglial response, neuronal density and cortical thickness. We found increased astroglial response in the superficial cortical layers of all mice compared to contralateral unimplanted controls. This difference was largest at the first time point and decreased over time. Neuronal density was lower on the implanted side only at the last time point, while cortical thickness was smaller in the first and second time points, but not at the last. In this study, we present data that confirms the feasibility and chronic use of Parylene HT/ITO ECoG devices.
Collapse
|
8
|
Munz M, Bharioke A, Kosche G, Moreno-Juan V, Brignall A, Rodrigues TM, Graff-Meyer A, Ulmer T, Haeuselmann S, Pavlinic D, Ledergerber N, Gross-Scherf B, Rózsa B, Krol J, Picelli S, Cowan CS, Roska B. Pyramidal neurons form active, transient, multilayered circuits perturbed by autism-associated mutations at the inception of neocortex. Cell 2023; 186:1930-1949.e31. [PMID: 37071993 PMCID: PMC10156177 DOI: 10.1016/j.cell.2023.03.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 02/01/2023] [Accepted: 03/22/2023] [Indexed: 04/20/2023]
Abstract
Cortical circuits are composed predominantly of pyramidal-to-pyramidal neuron connections, yet their assembly during embryonic development is not well understood. We show that mouse embryonic Rbp4-Cre cortical neurons, transcriptomically closest to layer 5 pyramidal neurons, display two phases of circuit assembly in vivo. At E14.5, they form a multi-layered circuit motif, composed of only embryonic near-projecting-type neurons. By E17.5, this transitions to a second motif involving all three embryonic types, analogous to the three adult layer 5 types. In vivo patch clamp recordings and two-photon calcium imaging of embryonic Rbp4-Cre neurons reveal active somas and neurites, tetrodotoxin-sensitive voltage-gated conductances, and functional glutamatergic synapses, from E14.5 onwards. Embryonic Rbp4-Cre neurons strongly express autism-associated genes and perturbing these genes interferes with the switch between the two motifs. Hence, pyramidal neurons form active, transient, multi-layered pyramidal-to-pyramidal circuits at the inception of neocortex, and studying these circuits could yield insights into the etiology of autism.
Collapse
|
9
|
Szadai Z, Pi HJ, Chevy Q, Ócsai K, Albeanu DF, Chiovini B, Szalay G, Katona G, Kepecs A, Rózsa B. Cortex-wide response mode of VIP-expressing inhibitory neurons by reward and punishment. eLife 2022; 11:e78815. [PMID: 36416886 PMCID: PMC9683790 DOI: 10.7554/elife.78815] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 10/23/2022] [Indexed: 11/24/2022] Open
Abstract
Neocortex is classically divided into distinct areas, each specializing in different function, but all could benefit from reinforcement feedback to inform and update local processing. Yet it remains elusive how global signals like reward and punishment are represented in local cortical computations. Previously, we identified a cortical neuron type, vasoactive intestinal polypeptide (VIP)-expressing interneurons, in auditory cortex that is recruited by behavioral reinforcers and mediates disinhibitory control by inhibiting other inhibitory neurons. As the same disinhibitory cortical circuit is present virtually throughout cortex, we wondered whether VIP neurons are likewise recruited by reinforcers throughout cortex. We monitored VIP neural activity in dozens of cortical regions using three-dimensional random access two-photon microscopy and fiber photometry while mice learned an auditory discrimination task. We found that reward and punishment during initial learning produce rapid, cortex-wide activation of most VIP interneurons. This global recruitment mode showed variations in temporal dynamics in individual neurons and across areas. Neither the weak sensory tuning of VIP interneurons in visual cortex nor their arousal state modulation was fully predictive of reinforcer responses. We suggest that the global response mode of cortical VIP interneurons supports a cell-type-specific circuit mechanism by which organism-level information about reinforcers regulates local circuit processing and plasticity.
Collapse
|
10
|
Meltzer AZ, Fintha A, Cseprekál O, Somogyi D, Szabó J, Kóbori L, Rózsa B, Piros L, Huszty G. Graft Arterial Dissection and Thrombosis After Kidney Transplantation With Undiagnosed Fibromuscular Dysplasia From a Deceased Donor: Case Report and Review. Transplant Proc 2022; 54:2603-2607. [DOI: 10.1016/j.transproceed.2022.10.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
11
|
Nagy G, Gerlei Z, Haboub-Sandil A, Görög D, Szabó J, Kóbori L, Huszty G, Bihari L, Rózsa B, Pőcze B, Máthé Z, Piros L. Optimizing Survival for Hepatocellular Carcinoma After Liver Transplantation: A Single-Center Report and Current Perspectives. Transplant Proc 2022; 54:2593-2597. [DOI: 10.1016/j.transproceed.2022.10.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
12
|
Kovács E, Cseri L, Jancsó A, Terényi F, Fülöp A, Rózsa B, Galbács G, Mucsi Z. Synthesis and Fluorescence Mechanism of the Aminoimidazolone Analogues of the Green Fluorescent Protein: Towards Advanced Dyes with Enhanced Stokes Shift, Quantum Yield and Two‐Photon Absorption. European J Org Chem 2021. [DOI: 10.1002/ejoc.202101173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
13
|
Chiovini B, Pálfi D, Majoros M, Juhász G, Szalay G, Katona G, Szőri M, Frigyesi O, Lukácsné Haveland C, Szabó G, Erdélyi F, Máté Z, Szadai Z, Madarász M, Dékány M, Csizmadia IG, Kovács E, Rózsa B, Mucsi Z. Theoretical Design, Synthesis, and In Vitro Neurobiological Applications of a Highly Efficient Two-Photon Caged GABA Validated on an Epileptic Case. ACS OMEGA 2021; 6:15029-15045. [PMID: 34151084 PMCID: PMC8210458 DOI: 10.1021/acsomega.1c01164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/20/2021] [Indexed: 06/13/2023]
Abstract
In this paper, we present an additional, new cage-GABA compound, called 4-amino-1-(4'-dimethylaminoisopropoxy-5',7'-dinitro-2',3'-dihydro-indol-1-yl)-1-oxobutane-γ-aminobutyric acid (iDMPO-DNI-GABA), and currently, this compound is the only photoreagent, which can be applied for GABA uncaging without experimental compromises. By a systematic theoretical design and successful synthesis of several compounds, the best reagent exhibits a high two-photon efficiency within the 700-760 nm range with excellent pharmacological behavior, which proved to be suitable for a complex epileptic study. Quantum chemical design showed that the optimal length of the cationic side chain enhances the two-photon absorption by 1 order of magnitude due to the cooperating internal hydrogen bonding to the extra nitro group on the core. This feature increased solubility while suppressing membrane permeability. The efficiency was demonstrated in a systematic, wide range of in vitro single-cell neurophysiological experiments by electrophysiological as well as calcium imaging techniques. Scalable inhibitory ion currents were elicited by iDMPO-DNI-GABA with appropriate spatial-temporal precision, blocking both spontaneous and evoked cell activity with excellent efficiency. Additionally, to demonstrate its applicability in a real neurobiological study, we could smoothly and selectively modulate neuronal activities during artificial epileptic rhythms first time in a neural network of GCaMP6f transgenic mouse brain slices.
Collapse
|
14
|
Kaszas A, Szalay G, Slézia A, Bojdán A, Vanzetta I, Hangya B, Rózsa B, O'Connor R, Moreau D. Two-photon GCaMP6f imaging of infrared neural stimulation evoked calcium signals in mouse cortical neurons in vivo. Sci Rep 2021; 11:9775. [PMID: 33963220 PMCID: PMC8105372 DOI: 10.1038/s41598-021-89163-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 04/22/2021] [Indexed: 02/07/2023] Open
Abstract
Infrared neural stimulation is a promising tool for stimulating the brain because it can be used to excite with high spatial precision without the need of delivering or inserting any exogenous agent into the tissue. Very few studies have explored its use in the brain, as most investigations have focused on sensory or motor nerve stimulation. Using intravital calcium imaging with the genetically encoded calcium indicator GCaMP6f, here we show that the application of infrared neural stimulation induces intracellular calcium signals in Layer 2/3 neurons in mouse cortex in vivo. The number of neurons exhibiting infrared-induced calcium response as well as the amplitude of those signals are shown to be both increasing with the energy density applied. By studying as well the spatial extent of the stimulation, we show that reproducibility of the stimulation is achieved mainly in the central part of the infrared beam path. Stimulating in vivo at such a degree of precision and without any exogenous chromophores enables multiple applications, from mapping the brain's connectome to applications in systems neuroscience and the development of new therapeutic tools for investigating the pathological brain.
Collapse
|
15
|
Lage-Rupprecht V, Zhou L, Bianchini G, Aghvami SS, Mueller M, Rózsa B, Sassoè-Pognetto M, Egger V. Presynaptic NMDARs cooperate with local spikes toward GABA release from the reciprocal olfactory bulb granule cell spine. eLife 2020; 9:e63737. [PMID: 33252329 PMCID: PMC7704106 DOI: 10.7554/elife.63737] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 11/10/2020] [Indexed: 12/16/2022] Open
Abstract
In the rodent olfactory bulb the smooth dendrites of the principal glutamatergic mitral cells (MCs) form reciprocal dendrodendritic synapses with large spines on GABAergic granule cells (GC), where unitary release of glutamate can trigger postsynaptic local activation of voltage-gated Na+-channels (Navs), that is a spine spike. Can such single MC input evoke reciprocal release? We find that unitary-like activation via two-photon uncaging of glutamate causes GC spines to release GABA both synchronously and asynchronously onto MC dendrites. This release indeed requires activation of Navs and high-voltage-activated Ca2+-channels (HVACCs), but also of NMDA receptors (NMDAR). Simulations show temporally overlapping HVACC- and NMDAR-mediated Ca2+-currents during the spine spike, and ultrastructural data prove NMDAR presence within the GABAergic presynapse. This cooperative action of presynaptic NMDARs allows to implement synapse-specific, activity-dependent lateral inhibition, and thus could provide an efficient solution to combinatorial percept synthesis in a sensory system with many receptor channels.
Collapse
|
16
|
Hu HY, Kruijssen DLH, Frias CP, Rózsa B, Hoogenraad CC, Wierenga CJ. Endocannabinoid Signaling Mediates Local Dendritic Coordination between Excitatory and Inhibitory Synapses. Cell Rep 2020; 27:666-675.e5. [PMID: 30995465 DOI: 10.1016/j.celrep.2019.03.078] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 12/21/2018] [Accepted: 03/21/2019] [Indexed: 01/01/2023] Open
Abstract
Dendritic inhibitory synapses are most efficient in modulating excitatory inputs localized on the same dendrite, but it is unknown whether their location is random or regulated. Here, we show that the formation of inhibitory synapses can be directed by excitatory synaptic activity on the same dendrite. We stimulated dendritic spines close to a GABAergic axon crossing by pairing two-photon glutamate uncaging with postsynaptic depolarization in CA1 pyramidal cells. We found that repeated spine stimulation promoted growth of a GABAergic bouton onto the same dendrite. The dendritic feedback signal required postsynaptic activation of DAGL, which produces the endocannabinoid 2-AG, and was mediated by CB1 receptors. We could also induce inhibitory bouton growth by local, brief applications of 2-AG. Our findings reveal a dendritic signaling mechanism to trigger growth of an inhibitory bouton at dendritic locations with strong excitatory synaptic activity, and this mechanism may serve to ensure inhibitory control over clustered excitatory inputs.
Collapse
|
17
|
Zátonyi A, Madarász M, Szabó Á, Lőrincz T, Hodován R, Rózsa B, Fekete Z. Transparent, low-autofluorescence microECoG device for simultaneous Ca2+imaging and cortical electrophysiologyin vivo. J Neural Eng 2020; 17:016062. [DOI: 10.1088/1741-2552/ab603f] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
18
|
Farkas E, Varga E, Kovács B, Szilvásy-Szabó A, Cote-Vélez A, Péterfi Z, Matziari M, Tóth M, Zelena D, Mezriczky Z, Kádár A, Kővári D, Watanabe M, Kano M, Mackie K, Rózsa B, Ruska Y, Tóth B, Máté Z, Erdélyi F, Szabó G, Gereben B, Lechan RM, Charli JL, Joseph-Bravo P, Fekete C. A Glial-Neuronal Circuit in the Median Eminence Regulates Thyrotropin-Releasing Hormone-Release via the Endocannabinoid System. iScience 2020; 23:100921. [PMID: 32143135 PMCID: PMC7058404 DOI: 10.1016/j.isci.2020.100921] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 05/20/2019] [Accepted: 02/12/2020] [Indexed: 12/21/2022] Open
Abstract
Based on the type-I cannabinoid receptor (CB1) content of hypophysiotropic axons and the involvement of tanycytes in the regulation of the hypothalamic-pituitary-thyroid (HPT) axis, we hypothesized that endocannabinoids are involved in the tanycyte-induced regulation of TRH release in the median eminence (ME). We demonstrated that CB1-immunoreactive TRH axons were associated to DAGLα-immunoreactive tanycyte processes in the external zone of ME and showed that endocannabinoids tonically inhibit the TRH release in this tissue. We showed that glutamate depolarizes the tanycytes, increases their intracellular Ca2+ level and the 2-AG level of the ME via AMPA and kainite receptors and glutamate transport. Using optogenetics, we demonstrated that glutamate released from TRH neurons influences the tanycytes in the ME. In summary, tanycytes regulate TRH secretion in the ME via endocannabinoid release, whereas TRH axons regulate tanycytes by glutamate, suggesting the existence of a reciprocal microcircuit between tanycytes and TRH terminals that controls TRH release.
Tanycytes tonically inhibit the activity of TRH axons via endocannabinoid release Glutamate depolarizes the tanycytes and regulates their 2-AG synthesis Glutamate released from the hypophysiotropic TRH axons influences tanycytes A microcircuit utilizing glutamate and endocannabinoids regulates TRH release
Collapse
|
19
|
Orbán G, Meszéna D, Tasnády KR, Rózsa B, Ulbert I, Márton G. Correction: Method for spike detection from microelectrode array recordings contaminated by artifacts of simultaneous two-photon imaging. PLoS One 2019; 14:e0224590. [PMID: 31648240 PMCID: PMC6812817 DOI: 10.1371/journal.pone.0224590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
|
20
|
Pálfi D, Chiovini B, Szalay G, Kaszás A, Turi GF, Katona G, Ábrányi-Balogh P, Szőri M, Potor A, Frigyesi O, Lukácsné Haveland C, Szadai Z, Madarász M, Vasanits-Zsigrai A, Molnár-Perl I, Viskolcz B, Csizmadia IG, Mucsi Z, Rózsa B. High efficiency two-photon uncaging coupled by the correction of spontaneous hydrolysis. Org Biomol Chem 2019; 16:1958-1970. [PMID: 29497727 DOI: 10.1039/c8ob00025e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two-photon (TP) uncaging of neurotransmitter molecules is the method of choice to mimic and study the subtleties of neuronal communication either in the intact brain or in slice preparations. However, the currently available caged materials are just at the limit of their usability and have several drawbacks. The local and focal nature of their use may for example be jeopardized by a high spontaneous hydrolysis rate of the commercially available compounds with increased photochemical release rate. Here, using quantum chemical modelling we show the mechanisms of hydrolysis and two-photon activation, and synthesized more effective caged compounds. Furthermore, we have developed a new enzymatic elimination method removing neurotransmitters inadvertently escaping from their compound during experiment. This method, usable both in one and two-photon experiments, allows for the use of materials with an increased rate of photochemical release. The efficiency of the new compound and the enzymatic method and of the new compound are demonstrated in neurophysiological experiments.
Collapse
|
21
|
Wettstein D, Hamar M, Cseprekál O, Tóth SJ, Rózsa B, Remport Á, Máthé Z. Szervkonzerválás gépi perfúzióval: új lehetőségek a hasi szervek transzplantációjában. Orv Hetil 2018; 159:1882-1890. [DOI: 10.1556/650.2018.31282] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract: Machine perfusion of marginal grafts might be a possible solution to organ shortage and a promising tool for reducing waiting list morbidity and mortality. In recent years, optimizing the circumstances of organ preservation prior to implantation via machine perfusion has become a hot topic of research. Machine perfusion offers a platform for organ reconditioning, assessment of cell viability and function, pharmacological preconditioning, prolongation of preservation time (ischemia time) and finally reducing graft injury. The objective of the new technology is to increase the pool of transplantable organs safely. Multicentric prospective studies have been evaluating the short and long term outcomes of different methods, however, several questions still remain unanswered. This review summarizes the recent advances in the field of machine perfusion, focusing on preclinical and clinical results. Machine perfusion seems to be a new milestone in the modern era of solid organ transplantation. Orv Hetil. 2018; 159(46): 1882–1890.
Collapse
|
22
|
Theis AK, Rózsa B, Katona G, Schmitz D, Johenning FW. Voltage Gated Calcium Channel Activation by Backpropagating Action Potentials Downregulates NMDAR Function. Front Cell Neurosci 2018; 12:109. [PMID: 29755321 PMCID: PMC5932410 DOI: 10.3389/fncel.2018.00109] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 04/03/2018] [Indexed: 12/20/2022] Open
Abstract
The majority of excitatory synapses are located on dendritic spines of cortical glutamatergic neurons. In spines, compartmentalized Ca2+ signals transduce electrical activity into specific long-term biochemical and structural changes. Action potentials (APs) propagate back into the dendritic tree and activate voltage gated Ca2+ channels (VGCCs). For spines, this global mode of spine Ca2+ signaling is a direct biochemical feedback of suprathreshold neuronal activity. We previously demonstrated that backpropagating action potentials (bAPs) result in long-term enhancement of spine VGCCs. This activity-dependent VGCC plasticity results in a large interspine variability of VGCC Ca2+ influx. Here, we investigate how spine VGCCs affect glutamatergic synaptic transmission. We combined electrophysiology, two-photon Ca2+ imaging and two-photon glutamate uncaging in acute brain slices from rats. T- and R-type VGCCs were the dominant depolarization-associated Ca2+conductances in dendritic spines of excitatory layer 2 neurons and do not affect synaptic excitatory postsynaptic potentials (EPSPs) measured at the soma. Using two-photon glutamate uncaging, we compared the properties of glutamatergic synapses of single spines that express different levels of VGCCs. While VGCCs contributed to EPSP mediated Ca2+ influx, the amount of EPSP mediated Ca2+ influx is not determined by spine VGCC expression. On a longer timescale, the activation of VGCCs by bAP bursts results in downregulation of spine NMDAR function.
Collapse
|
23
|
Szabó Z, Héja L, Szalay G, Kékesi O, Füredi A, Szebényi K, Dobolyi Á, Orbán TI, Kolacsek O, Tompa T, Miskolczy Z, Biczók L, Rózsa B, Sarkadi B, Kardos J. Extensive astrocyte synchronization advances neuronal coupling in slow wave activity in vivo. Sci Rep 2017; 7:6018. [PMID: 28729692 PMCID: PMC5519671 DOI: 10.1038/s41598-017-06073-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 05/26/2017] [Indexed: 01/19/2023] Open
Abstract
Slow wave activity (SWA) is a characteristic brain oscillation in sleep and quiet wakefulness. Although the cell types contributing to SWA genesis are not yet identified, the principal role of neurons in the emergence of this essential cognitive mechanism has not been questioned. To address the possibility of astrocytic involvement in SWA, we used a transgenic rat line expressing a calcium sensitive fluorescent protein in both astrocytes and interneurons and simultaneously imaged astrocytic and neuronal activity in vivo. Here we demonstrate, for the first time, that the astrocyte network display synchronized recurrent activity in vivo coupled to UP states measured by field recording and neuronal calcium imaging. Furthermore, we present evidence that extensive synchronization of the astrocytic network precedes the spatial build-up of neuronal synchronization. The earlier extensive recruitment of astrocytes in the synchronized activity is reinforced by the observation that neurons surrounded by active astrocytes are more likely to join SWA, suggesting causality. Further supporting this notion, we demonstrate that blockade of astrocytic gap junctional communication or inhibition of astrocytic Ca2+ transients reduces the ratio of both astrocytes and neurons involved in SWA. These in vivo findings conclusively suggest a causal role of the astrocytic syncytium in SWA generation.
Collapse
|
24
|
Szalay G, Judák L, Katona G, Ócsai K, Juhász G, Veress M, Szadai Z, Fehér A, Tompa T, Chiovini B, Maák P, Rózsa B. Fast 3D Imaging of Spine, Dendritic, and Neuronal Assemblies in Behaving Animals. Neuron 2016; 92:723-738. [PMID: 27773582 PMCID: PMC5167293 DOI: 10.1016/j.neuron.2016.10.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Revised: 07/19/2016] [Accepted: 09/20/2016] [Indexed: 11/19/2022]
Abstract
Understanding neural computation requires methods such as 3D acousto-optical (AO) scanning that can simultaneously read out neural activity on both the somatic and dendritic scales. AO point scanning can increase measurement speed and signal-to-noise ratio (SNR) by several orders of magnitude, but high optical resolution requires long point-to-point switching time, which limits imaging capability. Here we present a novel technology, 3D DRIFT AO scanning, which can extend each scanning point to small 3D lines, surfaces, or volume elements for flexible and fast imaging of complex structures simultaneously in multiple locations. Our method was demonstrated by fast 3D recording of over 150 dendritic spines with 3D lines, over 100 somata with squares and cubes, or multiple spiny dendritic segments with surface and volume elements, including in behaving animals. Finally, a 4-fold improvement in total excitation efficiency resulted in about 500 × 500 × 650 μm scanning volume with genetically encoded calcium indicators (GECIs).
Collapse
|
25
|
Szalay G, Martinecz B, Lénárt N, Környei Z, Orsolits B, Judák L, Császár E, Fekete R, West BL, Katona G, Rózsa B, Dénes Á. Microglia protect against brain injury and their selective elimination dysregulates neuronal network activity after stroke. Nat Commun 2016; 7:11499. [PMID: 27139776 PMCID: PMC4857403 DOI: 10.1038/ncomms11499] [Citation(s) in RCA: 438] [Impact Index Per Article: 48.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 04/04/2016] [Indexed: 12/15/2022] Open
Abstract
Microglia are the main immune cells of the brain and contribute to common brain diseases. However, it is unclear how microglia influence neuronal activity and survival in the injured brain in vivo. Here we develop a precisely controlled model of brain injury induced by cerebral ischaemia combined with fast in vivo two-photon calcium imaging and selective microglial manipulation. We show that selective elimination of microglia leads to a striking, 60% increase in infarct size, which is reversed by microglial repopulation. Microglia-mediated protection includes reduction of excitotoxic injury, since an absence of microglia leads to dysregulated neuronal calcium responses, calcium overload and increased neuronal death. Furthermore, the incidence of spreading depolarization (SD) is markedly reduced in the absence of microglia. Thus, microglia are involved in changes in neuronal network activity and SD after brain injury in vivo that could have important implications for common brain diseases.
Collapse
|