1
|
Suryavanshi P, Langton R, Fairhead K, Glykys J. Brief and diverse excitotoxic insults cause an increase in neuronal nuclear membrane permeability in the neonatal brain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.22.554167. [PMID: 37662276 PMCID: PMC10473591 DOI: 10.1101/2023.08.22.554167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Neuronal swelling after excitotoxic insults is implicated in neuronal injury and death in the developing brain, yet mitigating brain edema with osmotic and surgical interventions yields poor clinical outcomes. Importantly, neuronal swelling and its downstream consequences during early brain development remain poorly investigated. Using multiphoton Ca2+ imaging in vivo (P12-17) and in acute brain slices (P8-12), we explored Ca2+-dependent downstream effects after neuronal cytotoxic edema. We observed the translocation of cytosolic GCaMP6s into the nucleus of a subpopulation of neurons minutes after various excitotoxic insults. We used automated morphology-detection algorithms for neuronal segmentation and quantified the nuclear translocation of GCaMP6s as the ratio of nuclear and cytosolic intensity (N/C ratio). Elevated neuronal N/C ratios were correlated to higher Ca2+ loads and could occur independently of neuronal swelling. Electron microscopy revealed that the nuclear translocation was associated with increased nuclear pore size. Inhibiting calpains prevented elevated N/C ratios and neuronal swelling. Thus, our results indicate altered nuclear transport in a subpopulation of neurons shortly after injury in the developing brain, which can be used as an early biomarker of acute neuronal injury.
Collapse
Affiliation(s)
- P Suryavanshi
- Department of Pediatrics, University of Iowa, Iowa City, IA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA
| | - R Langton
- Department of Pediatrics, University of Iowa, Iowa City, IA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA
| | - K Fairhead
- Biomedical Sciences, College of Liberal Arts and Sciences, University of Iowa, Iowa City, IA
| | - J Glykys
- Department of Pediatrics, University of Iowa, Iowa City, IA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA
- Department of Neurology, University of Iowa, Iowa City, IA
| |
Collapse
|
2
|
Islam MS, Suryavanshi P, Baule SM, Glykys J, Baek S. A Deep Learning Approach for Neuronal Cell Body Segmentation in Neurons Expressing GCaMP Using a Swin Transformer. eNeuro 2023; 10:ENEURO.0148-23.2023. [PMID: 37704367 PMCID: PMC10523838 DOI: 10.1523/eneuro.0148-23.2023] [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: 05/05/2023] [Revised: 09/08/2023] [Accepted: 09/09/2023] [Indexed: 09/15/2023] Open
Abstract
Neuronal cell body analysis is crucial for quantifying changes in neuronal sizes under different physiological and pathologic conditions. Neuronal cell body detection and segmentation mainly rely on manual or pseudo-manual annotations. Manual annotation of neuronal boundaries is time-consuming, requires human expertise, and has intra/interobserver variances. Also, determining where the neuron's cell body ends and where the axons and dendrites begin is taxing. We developed a deep-learning-based approach that uses a state-of-the-art shifted windows (Swin) transformer for automated, reproducible, fast, and unbiased 2D detection and segmentation of neuronal somas imaged in mouse acute brain slices by multiphoton microscopy. We tested our Swin algorithm during different experimental conditions of low and high signal fluorescence. Our algorithm achieved a mean Dice score of 0.91, a precision of 0.83, and a recall of 0.86. Compared with two different convolutional neural networks, the Swin transformer outperformed them in detecting the cell boundaries of GCamP6s expressing neurons. Thus, our Swin transform algorithm can assist in the fast and accurate segmentation of fluorescently labeled neuronal cell bodies in thick acute brain slices. Using our flexible algorithm, researchers can better study the fluctuations in neuronal soma size during physiological and pathologic conditions.
Collapse
Affiliation(s)
| | - Pratyush Suryavanshi
- Department of Pediatrics, Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA 52242
| | - Samuel M Baule
- Department of Biomedical Engineering, The University of Iowa, Iowa City, IA 52242
| | - Joseph Glykys
- Department of Pediatrics, Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA 52242
- Department of Neurology, The University of Iowa, Iowa City, IA 52242
| | - Stephen Baek
- School of Data Science, The University of Virginia, Charlottesville, VA 22903
| |
Collapse
|
3
|
Welzel B, Johne M, Löscher W. Bumetanide potentiates the anti-seizure and disease-modifying effects of midazolam in a noninvasive rat model of term birth asphyxia. Epilepsy Behav 2023; 142:109189. [PMID: 37037061 DOI: 10.1016/j.yebeh.2023.109189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/15/2023] [Accepted: 03/16/2023] [Indexed: 04/12/2023]
Abstract
Birth asphyxia and the resulting hypoxic-ischemic encephalopathy (HIE) are highly associated with perinatal and neonatal death, neonatal seizures, and an adverse later-life outcome. Currently used drugs, including phenobarbital and midazolam, have limited efficacy to suppress neonatal seizures. There is a medical need to develop new therapies that not only suppress neonatal seizures but also prevent later-life consequences. We have previously shown that the loop diuretic bumetanide does not potentiate the effects of phenobarbital in a rat model of birth asphyxia. Here we compared the effects of bumetanide (0.3 or 10 mg/kg i.p.), midazolam (1 mg/kg i.p.), and a combination of bumetanide and midazolam on neonatal seizures and later-life outcomes in this model. While bumetanide at either dose was ineffective when administered alone, the higher dose of bumetanide markedly potentiated midazolam's effect on neonatal seizures. Median bumetanide brain levels (0.47-0.53 µM) obtained with the higher dose were in the range known to inhibit the Na-K-Cl-cotransporter NKCC1 but it remains to be determined whether brain NKCC1 inhibition was underlying the potentiation of midazolam. When behavioral and cognitive alterations were examined over three months after asphyxia, treatment with the bumetanide/midazolam combination, but not with bumetanide or midazolam alone, prevented impairment of learning and memory. Furthermore, the combination prevented the loss of neurons in the dentate hilus and aberrant mossy fiber sprouting in the CA3a area of the hippocampus. The molecular mechanisms that explain that bumetanide potentiates midazolam but not phenobarbital in the rat model of birth asphyxia remain to be determined.
Collapse
Affiliation(s)
- Björn Welzel
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience Hannover, Germany
| | - Marie Johne
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience Hannover, Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience Hannover, Germany.
| |
Collapse
|
4
|
Role of NKCC1 and KCC2 during hypoxia-induced neuronal swelling in the neonatal neocortex. Neurobiol Dis 2023; 178:106013. [PMID: 36706928 PMCID: PMC9945323 DOI: 10.1016/j.nbd.2023.106013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/21/2022] [Accepted: 01/22/2023] [Indexed: 01/26/2023] Open
Abstract
Neonatal hypoxia causes cytotoxic neuronal swelling by the entry of ions and water. Multiple water pathways have been implicated in neurons because these cells lack water channels, and their membrane has a low water permeability. NKCC1 and KCC2 are cation-chloride cotransporters (CCCs) involved in water movement in various cell types. However, the role of CCCs in water movement in neonatal neurons during hypoxia is unknown. We studied the effects of modulating CCCs pharmacologically on neuronal swelling in the neocortex (layer IV/V) of neonatal mice (post-natal day 8-13) during prolonged and brief hypoxia. We used acute brain slices from Clomeleon mice which express a ratiometric fluorophore sensitive to Cl- and exposed them to oxygen-glucose deprivation (OGD) while imaging neuronal size and [Cl-]i by multiphoton microscopy. Neurons were identified using a convolutional neural network algorithm, and changes in the somatic area and [Cl-]i were evaluated using a linear mixed model for repeated measures. We found that (1) neuronal swelling and Cl- accumulation began after OGD, worsened during 20 min of OGD, or returned to baseline during reoxygenation if the exposure to OGD was brief (10 min). (2) Neuronal swelling did not occur when the extracellular Cl- concentration was low. (3) Enhancing KCC2 activity did not alter OGD-induced neuronal swelling but prevented Cl- accumulation; (4) blocking KCC2 led to an increase in Cl- accumulation during prolonged OGD and aggravated neuronal swelling during reoxygenation; (5) blocking NKCC1 reduced neuronal swelling during early but not prolonged OGD and aggravated Cl- accumulation during prolonged OGD; and (6) treatment with the "broad" CCC blocker furosemide reduced both swelling and Cl- accumulation during prolonged and brief OGD, whereas simultaneous NKCC1 and KCC2 inhibition using specific pharmacological blockers aggravated neuronal swelling during prolonged OGD. We conclude that CCCs, and other non-CCCs, contribute to water movement in neocortical neurons during OGD in the neonatal period.
Collapse
|
5
|
Langton RL, Sharma S, Tiarks GC, Bassuk AG, Glykys J. Lacosamide decreases neonatal seizures without increasing apoptosis. Epilepsia 2022; 63:3051-3065. [PMID: 36168798 PMCID: PMC9742288 DOI: 10.1111/epi.17423] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 09/26/2022] [Accepted: 09/26/2022] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Many seizing neonates fail to respond to first-line anticonvulsant medications. Phenobarbital, an allosteric modulator of γ-aminobutyric acid type A (GABAA ) receptors, has low efficacy in treating neonatal seizures and causes neuronal apoptosis. Nonetheless, it is one of the most used anticonvulsants in this age group. In neonatal mice, phenobarbital's poor effectiveness is due in part to high intraneuronal chloride concentration, which causes GABA to exert depolarizing actions. Therefore, another approach to treat neonatal seizures could be to use anticonvulsants that do not rely on GABAergic modulation. We evaluated whether lacosamide decreases seizures in neonatal mice and whether it increases apoptosis in vitro and in vivo. METHODS In vitro, we measured the effect of different lacosamide concentrations on seizure-like activity induced by the pro-convulsant drug 4-aminopyridine in neocortical brain slices (layer IV/V) from neonatal (postnatal day 8-11) and adult (1-1.6 months old) C57BL/6J mice. In vivo, we recorded the effect of different lacosamide concentrations on neonatal behavioral seizures induced by kainic acid. We studied neocortical apoptosis in vitro and in vivo, measuring terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling signal and cleaved-caspase 3. RESULTS Lacosamide reduced epileptiform activity in neocortical brain slices of neonates and adults in a concentration-dependent manner. In vivo, lacosamide reduced the duration and number of behavioral seizures. Lacosamide did not increase total or neuronal apoptosis in the neocortex in vitro or in vivo. SIGNIFICANCE Lacosamide reduces neocortical seizure-like activity in neonatal mice in vitro and in vivo without an acute increase in apoptosis. Our results support the use of lacosamide to treat neonatal seizures, with the advantage of not increasing apoptosis acutely.
Collapse
Affiliation(s)
- Rachel L Langton
- Department of Pediatrics, Division of Child Neurology, University of Iowa, Iowa City, Iowa, USA.,Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa, USA
| | - Shaunik Sharma
- Department of Pediatrics, Division of Child Neurology, University of Iowa, Iowa City, Iowa, USA
| | - Grant C Tiarks
- Department of Pediatrics, Division of Child Neurology, University of Iowa, Iowa City, Iowa, USA
| | - Alexander G Bassuk
- Department of Pediatrics, Division of Child Neurology, University of Iowa, Iowa City, Iowa, USA.,Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa, USA.,Department of Neurology, University of Iowa, Iowa City, Iowa, USA
| | - Joseph Glykys
- Department of Pediatrics, Division of Child Neurology, University of Iowa, Iowa City, Iowa, USA.,Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa, USA.,Department of Neurology, University of Iowa, Iowa City, Iowa, USA
| |
Collapse
|
6
|
Sturgeon ML, Langton R, Sharma S, Cornell RA, Glykys J, Bassuk AG. The opioid antagonist naltrexone decreases seizure-like activity in genetic and chemically induced epilepsy models. Epilepsia Open 2021; 6:528-538. [PMID: 34664432 PMCID: PMC8408599 DOI: 10.1002/epi4.12512] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/23/2021] [Accepted: 05/18/2021] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVE A significant number of epileptic patients fail to respond to available anticonvulsive medications. To find new anticonvulsive medications, we evaluated FDA-approved drugs not known to be anticonvulsants. Using zebrafish larvae as an initial model system, we found that the opioid antagonist naltrexone exhibited an anticonvulsant effect. We validated this effect in three other epilepsy models and present naltrexone as a promising anticonvulsive candidate. METHODS Candidate anticonvulsant drugs, determined by our prior transcriptomics analysis of hippocampal tissue, were evaluated in a larval zebrafish model of human Dravet syndrome (scn1Lab mutants), in wild-type zebrafish larvae treated with the pro-convulsant drug pentylenetetrazole (PTZ), in wild-type C57bl/6J acute brain slices exposed to PTZ, and in wild-type mice treated with PTZ in vivo. Abnormal locomotion was determined behaviorally in zebrafish and mice and by field potential in neocortex layer IV/V and CA1 stratum pyramidale in the hippocampus. RESULTS The opioid antagonist naltrexone decreased abnormal locomotion in the larval zebrafish model of human Dravet syndrome (scn1Lab mutants) and wild-type larvae treated with the pro-convulsant drug PTZ. Naltrexone also decreased seizure-like events in acute brain slices of wild-type mice, and the duration and number of seizures in adult mice injected with PTZ. SIGNIFICANCE Our data reveal that naltrexone has anticonvulsive properties and is a candidate drug for seizure treatment.
Collapse
Affiliation(s)
| | - Rachel Langton
- Department of PediatricsDivision of Child NeurologyUniversity of IowaIowa CityIAUSA
- Iowa Neuroscience InstituteUniversity of IowaIowa CityIAUSA
| | | | - Robert A. Cornell
- Department of Anatomy and Cell BiologyUniversity of IowaIowa CityIAUSA
| | - Joseph Glykys
- Department of PediatricsDivision of Child NeurologyUniversity of IowaIowa CityIAUSA
- Iowa Neuroscience InstituteUniversity of IowaIowa CityIAUSA
- Department of NeurologyUniversity of IowaIowa CityIAUSA
| | - Alexander G. Bassuk
- Department of PediatricsDivision of Child NeurologyUniversity of IowaIowa CityIAUSA
- Iowa Neuroscience InstituteUniversity of IowaIowa CityIAUSA
- Department of NeurologyUniversity of IowaIowa CityIAUSA
| |
Collapse
|
7
|
Rahmati N, Normoyle KP, Glykys J, Dzhala VI, Lillis KP, Kahle KT, Raiyyani R, Jacob T, Staley KJ. Unique Actions of GABA Arising from Cytoplasmic Chloride Microdomains. J Neurosci 2021; 41:4957-4975. [PMID: 33903223 PMCID: PMC8197632 DOI: 10.1523/jneurosci.3175-20.2021] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/10/2021] [Accepted: 04/10/2021] [Indexed: 12/21/2022] Open
Abstract
Developmental, cellular, and subcellular variations in the direction of neuronal Cl- currents elicited by GABAA receptor activation have been frequently reported. We found a corresponding variance in the GABAA receptor reversal potential (EGABA) for synapses originating from individual interneurons onto a single pyramidal cell. These findings suggest a similar heterogeneity in the cytoplasmic intracellular concentration of chloride ([Cl-]i) in individual dendrites. We determined [Cl-]i in the murine hippocampus and cerebral cortex of both sexes by (1) two-photon imaging of the Cl--sensitive, ratiometric fluorescent protein SuperClomeleon; (2) Fluorescence Lifetime IMaging (FLIM) of the Cl--sensitive fluorophore MEQ (6-methoxy-N-ethylquinolinium); and (3) electrophysiological measurements of EGABA by pressure application of GABA and RuBi-GABA uncaging. Fluorometric and electrophysiological estimates of local [Cl-]i were highly correlated. [Cl-]i microdomains persisted after pharmacological inhibition of cation-chloride cotransporters, but were progressively modified after inhibiting the polymerization of the anionic biopolymer actin. These methods collectively demonstrated stable [Cl-]i microdomains in individual neurons in vitro and in vivo and the role of immobile anions in its stability. Our results highlight the existence of functionally significant neuronal Cl- microdomains that modify the impact of GABAergic inputs.SIGNIFICANCE STATEMENT Microdomains of varying chloride concentrations in the neuronal cytoplasm are a predictable consequence of the inhomogeneous distribution of anionic polymers such as actin, tubulin, and nucleic acids. Here, we demonstrate the existence and stability of these microdomains, as well as the consequence for GABAergic synaptic signaling: each interneuron produces a postsynaptic GABAA response with a unique reversal potential. In individual hippocampal pyramidal cells, the range of GABAA reversal potentials evoked by stimulating different interneurons was >20 mV. Some interneurons generated postsynaptic responses in pyramidal cells that reversed at potentials beyond what would be considered purely inhibitory. Cytoplasmic chloride microdomains enable each pyramidal cell to maintain a compendium of unique postsynaptic responses to the activity of individual interneurons.
Collapse
Affiliation(s)
- Negah Rahmati
- Department of Neurology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Kieran P Normoyle
- Department of Neurology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Joseph Glykys
- Department of Pediatrics and Neurology, Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Volodymyr I Dzhala
- Department of Neurology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Kyle P Lillis
- Department of Neurology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Kristopher T Kahle
- Departments of Neurosurgery, Pediatrics, and Cellular & Molecular Physiology, Yale School of Medicine, New Haven, Connecticut 06510
| | - Rehan Raiyyani
- Department of Neurology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Theju Jacob
- Department of Neurology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Kevin J Staley
- Department of Neurology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114
| |
Collapse
|
8
|
Colbourn R, Hrabe J, Nicholson C, Perkins M, Goodman JH, Hrabetova S. Rapid volume pulsation of the extracellular space coincides with epileptiform activity in mice and depends on the NBCe1 transporter. J Physiol 2021; 599:3195-3220. [PMID: 33942325 DOI: 10.1113/jp281544] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/19/2021] [Indexed: 01/06/2023] Open
Abstract
KEY POINTS Extracellular space (ECS) rapid volume pulsation (RVP) accompanying epileptiform activity is described for the first time. Such RVP occurs robustly in several in vitro and in vivo mouse models of epileptiform activity. In the in vitro 4-aminopyridine model of epileptiform activity, RVP depends on the activity of the electrogenic Na+ /HCO3 - cotransporter (NBCe1). NBCe1 pharmacological inhibition suppresses RVP and epileptiform activity. Inhibition of changes in ECS volume may be a useful target in epilepsy patients who are resistant to current treatments. ABSTRACT: The extracellular space (ECS) of the brain shrinks persistently by approximately 35% during epileptic seizures. Here we report the discovery of rapid volume pulsation (RVP), further transient drops in ECS volume which accompany events of epileptiform activity. These transient ECS contractions were observed in multiple mouse models of epileptiform activity both in vivo (bicuculline methiodide model) and in vitro (hyaluronan synthase 3 knock-out, picrotoxin, bicuculline and 4-aminopyridine models). By using the probe transients quantification (PTQ) method we show that individual pulses of RVP shrank the ECS by almost 15% in vivo. In the 4-aminopyridine in vitro model, the individual pulses of RVP shrank the ECS by more than 4%, and these transient changes were superimposed on a persistent ECS shrinkage of 36% measured with the real-time iontophoretic method. In this in vitro model, we investigated several channels and transporters that may be required for the generation of RVP and epileptiform activity. Pharmacological blockages of Na+ /K+ /2Cl- cotransporter type 1 (NKCC1), K+ /Cl- cotransporter (KCC2), the water channel aquaporin-4 (AQP4) and inwardly rectifying potassium channel 4.1 (Kir4.1) were ineffective in halting the RVP and the epileptiform activity. In contrast, pharmacological blockade of the electrogenic Na+ /HCO3 - cotransporter (NBCe1) by 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS) eliminated both the RVP and the persistent ECS shrinkage. Importantly, this blocker also stopped the epileptiform activity. These results demonstrate that RVP is closely associated with epileptiform activity across several models of epileptiform activity and therefore the underlying mechanism could potentially represent a novel target for epilepsy management and treatment.
Collapse
Affiliation(s)
- Robert Colbourn
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, New York, USA.,Neural and Behavioral Science Graduate Program, SUNY Downstate Health Sciences University, Brooklyn, New York, USA
| | - Jan Hrabe
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, New York, USA.,Medical Physics Laboratory, Center for Biomedical Imaging and Neuromodulation, Nathan S. Kline Institute, Orangeburg, New York, USA
| | - Charles Nicholson
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, New York, USA.,Department of Neuroscience and Physiology, NYU Grossman School of Medicine, New York, New York, USA
| | - Matthew Perkins
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, New York, USA
| | - Jeffrey H Goodman
- Department of Developmental Neurobiology, The New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, USA.,Department of Physiology and Pharmacology, SUNY Downstate Health Sciences University, Brooklyn, New York, USA.,Department of Neurology, SUNY Downstate Health Sciences University, Brooklyn, New York, USA.,The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Health Sciences University, Brooklyn, New York, USA
| | - Sabina Hrabetova
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, New York, USA.,The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Health Sciences University, Brooklyn, New York, USA
| |
Collapse
|
9
|
Tong L, Langton R, Glykys J, Baek S. ANMAF: an automated neuronal morphology analysis framework using convolutional neural networks. Sci Rep 2021; 11:8179. [PMID: 33854113 PMCID: PMC8046969 DOI: 10.1038/s41598-021-87471-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 03/30/2021] [Indexed: 11/13/2022] Open
Abstract
Measurement of neuronal size is challenging due to their complex histology. Current practice includes manual or pseudo-manual measurement of somatic areas, which is labor-intensive and prone to human biases and intra-/inter-observer variances. We developed a novel high-throughput neuronal morphology analysis framework (ANMAF), using convolutional neural networks (CNN) to automatically contour the somatic area of fluorescent neurons in acute brain slices. Our results demonstrate considerable agreements between human annotators and ANMAF on detection, segmentation, and the area of somatic regions in neurons expressing a genetically encoded fluorophore. However, in contrast to humans, who exhibited significant variability in repeated measurements, ANMAF produced consistent neuronal contours. ANMAF was generalizable across different imaging protocols and trainable even with a small number of humanly labeled neurons. Our framework can facilitate more rigorous and quantitative studies of neuronal morphology by enabling the segmentation of many fluorescent neurons in thick brain slices in a standardized manner.
Collapse
Affiliation(s)
- Ling Tong
- Department of Business Analytics, University of Iowa, Iowa City, 52242, Iowa, United States
| | - Rachel Langton
- Departments of Pediatrics and Neurology, Iowa Neuroscience Institute, University of Iowa, Iowa City, 52242, Iowa, United States
| | - Joseph Glykys
- Departments of Pediatrics and Neurology, Iowa Neuroscience Institute, University of Iowa, Iowa City, 52242, Iowa, United States.
| | - Stephen Baek
- Department of Industrial and Systems Engineering, University of Iowa, Iowa City, 52242, Iowa, United States.
| |
Collapse
|
10
|
Sawant-Pokam PA, Vail TJ, Metcalf CS, Maguire JL, McKean TO, McKean NO, Brennan K. Preventing neuronal edema increases network excitability after traumatic brain injury. J Clin Invest 2020; 130:6005-6020. [PMID: 33044227 PMCID: PMC7598047 DOI: 10.1172/jci134793] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 08/06/2020] [Indexed: 12/31/2022] Open
Abstract
Edema is an important target for clinical intervention after traumatic brain injury (TBI). We used in vivo cellular resolution imaging and electrophysiological recording to examine the ionic mechanisms underlying neuronal edema and their effects on neuronal and network excitability after controlled cortical impact (CCI) in mice. Unexpectedly, we found that neuronal edema 48 hours after CCI was associated with reduced cellular and network excitability, concurrent with an increase in the expression ratio of the cation-chloride cotransporters (CCCs) NKCC1 and KCC2. Treatment with the CCC blocker bumetanide prevented neuronal swelling via a reversal in the NKCC1/KCC2 expression ratio, identifying altered chloride flux as the mechanism of neuronal edema. Importantly, bumetanide treatment was associated with increased neuronal and network excitability after injury, including increased susceptibility to spreading depolarizations (SDs) and seizures, known agents of clinical worsening after TBI. Treatment with mannitol, a first-line edema treatment in clinical practice, was also associated with increased susceptibility to SDs and seizures after CCI, showing that neuronal volume reduction, regardless of mechanism, was associated with an excitability increase. Finally, we observed an increase in excitability when neuronal edema normalized by 1 week after CCI. We conclude that neuronal swelling may exert protective effects against damaging excitability in the aftermath of TBI and that treatment of edema has the potential to reverse these effects.
Collapse
Affiliation(s)
| | | | - Cameron S. Metcalf
- Anticonvulsant Drug Development Program, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
| | - Jamie L. Maguire
- Neuroscience Department, Tufts University School of Medicine, Boston, Massachusetts, USA
| | | | | | - K.C. Brennan
- Department of Neurology, School of Medicine, and
| |
Collapse
|
11
|
Hamilton KA, Santhakumar V. Current ex Vivo and in Vitro Approaches to Uncovering Mechanisms of Neurological Dysfunction after Traumatic Brain Injury. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2020; 14:18-24. [PMID: 32548365 PMCID: PMC7297186 DOI: 10.1016/j.cobme.2020.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Traumatic brain injury often leads to progressive alterations at the molecular to circuit levels resulting in epilepsy and memory impairments. Ex vivo and in vitro models have provided a powerful platform for investigating the multimodal alteration after trauma. Recent ex vivo analyses using voltage sensitive dye imaging, optogenetics, and glutamate uncaging have revealed circuit abnormalities following in vivo brain injury. In vitro injury models have enabled examination of early and progressive changes in activity while development of three-dimensional organoids derived from human induced pluripotent stem cells have opened novel avenues for injury research. Here, we highlight recent advances in ex vivo and in vitro systems, focusing on their potential for advancing mechanistic understandings, possible limitations, and implications for therapeutics.
Collapse
Affiliation(s)
- Kelly Andrew Hamilton
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA, USA
| | - Vijayalakshmi Santhakumar
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA, USA
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, USA
| |
Collapse
|