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Sdobnov A, Tsytsarev V, Piavchenko G, Bykov A, Meglinski I. Beyond life: Exploring hemodynamic patterns in postmortem mice brains. J Biophotonics 2024:e202400017. [PMID: 38714530 DOI: 10.1002/jbio.202400017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 03/14/2024] [Accepted: 04/09/2024] [Indexed: 05/10/2024]
Abstract
We utilize Laser Speckle Contrast Imaging (LSCI) for visualizing cerebral blood flow in mice during and post-cardiac arrest. Analyzing LSCI images, we noted temporal blood flow variations across the brain surface for hours postmortem. Fast Fourier Transform (FFT) analysis depicted blood flow and microcirculation decay post-death. Continuous Wavelet Transform (CWT) identified potential cerebral hemodynamic synchronization patterns. Additionally, non-negative matrix factorization (NMF) with four components segmented LSCI images, revealing structural subcomponent alterations over time. This integrated approach of LSCI, FFT, CWT, and NMF offers a comprehensive tool for studying cerebral blood flow dynamics, metaphorically capturing the 'end of the tunnel' experience. Results showed primary postmortem hemodynamic activity in the olfactory bulbs, followed by blood microflow relocations between somatosensory and visual cortical regions via the superior sagittal sinus. This method opens new avenues for exploring these phenomena, potentially linking neuroscientific insights with mysteries surrounding consciousness and perception at life's end.
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Affiliation(s)
- Anton Sdobnov
- Optoelectronics and Measurement Techniques, University of Oulu, Oulu, Finland
| | - Vassiliy Tsytsarev
- Department of Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Gennadi Piavchenko
- Department of Human Anatomy and Histology, Institute of Clinical Medicine N.V. Sklifosovsky, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Alexander Bykov
- Optoelectronics and Measurement Techniques, University of Oulu, Oulu, Finland
| | - Igor Meglinski
- Department of Human Anatomy and Histology, Institute of Clinical Medicine N.V. Sklifosovsky, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
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Tsytsarev V, Plachez C, Zhao S, O'Connor DH, Erzurumlu RS. Bilateral Whisker Representations in the Primary Somatosensory Cortex in Robo3cKO Mice Are Reflected in the Primary Motor Cortex. Neuroscience 2024; 544:128-137. [PMID: 38447690 DOI: 10.1016/j.neuroscience.2024.02.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 02/09/2024] [Accepted: 02/28/2024] [Indexed: 03/08/2024]
Abstract
In Robo3cKO mice, midline crossing defects of the trigeminothalamic projections from the trigeminal principal sensory nucleus result in bilateral whisker maps in the somatosensory thalamus and consequently in the face representation area of the primary somatosensory (S1) cortex (Renier et al., 2017; Tsytsarev et al., 2017). We investigated whether this bilateral sensory representation in the whisker-barrel cortex is also reflected in the downstream projections from the S1 to the primary motor (M1) cortex. To label these projections, we injected anterograde viral axonal tracer in S1 cortex. Corticocortical projections from the S1 distribute to similar areas across the ipsilateral hemisphere in control and Robo3cKO mice. Namely, in both genotypes they extend to the M1, premotor/prefrontal cortex (PMPF), secondary somatosensory (S2) cortex. Next, we performed voltage-sensitive dye imaging (VSDi) in the left hemisphere following ipsilateral and contralateral single whisker stimulation. While controls showed only activation in the contralateral whisker barrel cortex and M1 cortex, the Robo3cKO mouse left hemisphere was activated bilaterally in both the barrel cortex and the M1 cortex. We conclude that the midline crossing defect of the trigeminothalamic projections leads to bilateral whisker representations not only in the thalamus and the S1 cortex but also downstream from the S1, in the M1 cortex.
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Affiliation(s)
- Vassiliy Tsytsarev
- Department of Neurobiology, University of Maryland School of Medicine, 20 Penn St, HSF-2, Baltimore, MD 21201, USA.
| | - Céline Plachez
- Department of Neurobiology, University of Maryland School of Medicine, 20 Penn St, HSF-2, Baltimore, MD 21201, USA.
| | - Shuxin Zhao
- Department of Neurobiology, University of Maryland School of Medicine, 20 Penn St, HSF-2, Baltimore, MD 21201, USA.
| | - Daniel H O'Connor
- The Zanvyl Krieger Mind/Brain Institute, The Johns Hopkins University, 3400 N. Charles Street, 338 Krieger Hall, Baltimore, MD 21218, USA.
| | - Reha S Erzurumlu
- Department of Neurobiology, University of Maryland School of Medicine, 20 Penn St, HSF-2, Baltimore, MD 21201, USA.
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Tsytsarev V, Sopova JV, Leonova EI, Inyushin M, Markina AA, Chirinskaite AV, Volnova AB. Neurophotonic methods in approach to in vivo animal epileptic models: Advantages and limitations. Epilepsia 2024; 65:600-614. [PMID: 38115808 PMCID: PMC10948300 DOI: 10.1111/epi.17870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 12/16/2023] [Accepted: 12/18/2023] [Indexed: 12/21/2023]
Abstract
Neurophotonic technology is a rapidly growing group of techniques that are based on the interactions of light with natural or genetically modified cells of the neural system. New optical technologies make it possible to considerably extend the tools of neurophysiological research, from the visualization of functional activity changes to control of brain tissue excitability. This opens new perspectives for studying the mechanisms underlying the development of human neurological diseases. Epilepsy is one of the most common brain disorders; it is characterized by recurrent seizures and affects >1% of the world's population. However, how seizures occur, spread, and terminate in a healthy brain is still unclear. Therefore, it is extremely important to develop appropriate models to accurately explore the causal relationship of epileptic activity. The use of neurophotonic technologies in epilepsy research falls into two broad categories: the visualization of neural epileptic activity, and the direct optical influence on neurons to induce or suppress epileptic activity. An optogenetic variant of the classical kindling model of epileptic seizures, in which activatable cells are genetically defined, is called optokindling. Research is also underway concerning the application of neurophotonic techniques for suppressing epileptic activity, aiming to bring these methods into clinical practice. This review aims to systematize and describe new approaches that use combinations of different neurophotonic methods to work with in vivo models of epilepsy. These approaches overcome many of the shortcomings associated with classical animal models of epilepsy and thus increase the effectiveness of developing new diagnostic methods and antiepileptic therapy.
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Affiliation(s)
- Vassiliy Tsytsarev
- University of Maryland School of Medicine, Department of Neurobiology 20 Penn St, HSF-2, 21201 MD, Baltimore, United States
| | - Julia V. Sopova
- Center of Transgenesis and Genome Editing, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Elena I. Leonova
- Center of Transgenesis and Genome Editing, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Mikhail Inyushin
- School of Medicine, Universidad Central del Caribe, Bayamon, PR 00956, USA
| | - Alisa A. Markina
- Institute of Translational Biomedicine, Saint Petersburg State University, St. Petersburg 199034, Russia
| | - Angelina V. Chirinskaite
- Center of Transgenesis and Genome Editing, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Anna B. Volnova
- Institute of Translational Biomedicine, Saint Petersburg State University, St. Petersburg 199034, Russia
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Wang Y, Tsytsarev V, Liao LD. In vivo laser speckle contrast imaging of 4-aminopyridine- or pentylenetetrazole-induced seizures. APL Bioeng 2023; 7:036119. [PMID: 37781728 PMCID: PMC10541235 DOI: 10.1063/5.0158791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 08/28/2023] [Indexed: 10/03/2023] Open
Abstract
Clinical and preclinical studies on epileptic seizures are closely linked to the study of neurovascular coupling. Obtaining reliable information about cerebral blood flow (CBF) in the area of epileptic activity through minimally invasive techniques is crucial for research in this field. In our studies, we used laser speckle contrast imaging (LSCI) to gather information about the local blood circulation in the area of epileptic activity. We used two models of epileptic seizures: one based on 4-aminopyridine (4-AP) and another based on pentylenetetrazole (PTZ). We verified the duration of an epileptic seizure using electrocorticography (ECoG). We applied the antiepileptic drug topiramate (TPM) to both models, but its effect was different in each case. However, in both models, TPM had an effect on neurovascular coupling in the area of epileptic activity, as shown by both LSCI and ECoG data. We demonstrated that TPM significantly reduced the amplitude of 4-AP-induced epileptic seizures (4-AP+TPM: 0.61 ± 0.13 mV vs 4-AP: 1.08 ± 0.19 mV; p < 0.05), and it also reduced gamma power in ECoG in PTZ-induced epileptic seizures (PTZ+TPM: 38.5% ± 11.9% of the peak value vs PTZ: 59.2% ± 3.0% of peak value; p < 0.05). We also captured the pattern of CBF changes during focal epileptic seizures induced by 4-AP. Our data confirm that the system of simultaneous cortical LSCI and registration of ECoG makes it possible to evaluate the effectiveness of pharmacological agents in various types of epileptic seizures in in vivo models and provides spatial and temporal information on the process of ictogenesis.
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Affiliation(s)
| | - Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, HSF-2, Baltimore, Maryland 21201, USA
| | - Lun-De Liao
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, No. 35, Keyan Rd., Zhunan Township, Miaoli County 350, Taiwan
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Pais-Vieira M, Aksenova T, Tsytsarev V, Faber J. Editorial: Sensorimotor decoding: characterization and modeling for rehabilitation and assistive technologies. Front Hum Neurosci 2023; 17:1243226. [PMID: 37533587 PMCID: PMC10392847 DOI: 10.3389/fnhum.2023.1243226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 07/05/2023] [Indexed: 08/04/2023] Open
Affiliation(s)
- Miguel Pais-Vieira
- Department of Medical Sciences, iBiMED—Institute of Biomedicine, University of Aveiro, Aveiro, Portugal
| | | | - Vassiliy Tsytsarev
- School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Jean Faber
- Division of Neuroscience, Department of Neurology and Neurosurgery, Escola Paulista de Medicina, Federal University of São Paulo, São Paulo, Brazil
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Sibarov DA, Tsytsarev V, Volnova A, Vaganova AN, Alves J, Rojas L, Sanabria P, Ignashchenkova A, Savage ED, Inyushin M. Arc protein, a remnant of ancient retrovirus, forms virus-like particles, which are abundantly generated by neurons during epileptic seizures, and affects epileptic susceptibility in rodent models. Front Neurol 2023; 14:1201104. [PMID: 37483450 PMCID: PMC10361770 DOI: 10.3389/fneur.2023.1201104] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 06/02/2023] [Indexed: 07/25/2023] Open
Abstract
A product of the immediate early gene Arc (Activity-regulated cytoskeleton-associated protein or Arc protein) of retroviral ancestry resides in the genome of all tetrapods for millions of years and is expressed endogenously in neurons. It is a well-known protein, very important for synaptic plasticity and memory consolidation. Activity-dependent Arc expression concentrated in glutamatergic synapses affects the long-time synaptic strength of those excitatory synapses. Because it modulates excitatory-inhibitory balance in a neuronal network, the Arc gene itself was found to be related to the pathogenesis of epilepsy. General Arc knockout rodent models develop a susceptibility to epileptic seizures. Because of activity dependence, synaptic Arc protein synthesis also is affected by seizures. Interestingly, it was found that Arc protein in synapses of active neurons self-assemble in capsids of retrovirus-like particles, which can transfer genetic information between neurons, at least across neuronal synaptic boutons. Released Arc particles can be accumulated in astrocytes after seizures. It is still not known how capsid assembling and transmission timescale is affected by seizures. This scientific field is relatively novel and is experiencing swift transformation as it grapples with difficult concepts in light of evolving experimental findings. We summarize the emergent literature on the subject and also discuss the specific rodent models for studying Arc effects in epilepsy. We summarized both to clarify the possible role of Arc-related pseudo-viral particles in epileptic disorders, which may be helpful to researchers interested in this growing area of investigation.
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Affiliation(s)
- Dmitry A. Sibarov
- Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, Saint Petersburg, Russia
| | - Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Anna Volnova
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
| | - Anastasia N. Vaganova
- Institute of Translational Biomedicine, Saint Petersburg State University, Saint Petersburg, Russia
| | - Janaina Alves
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
| | - Legier Rojas
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
| | - Priscila Sanabria
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
| | | | | | - Mikhail Inyushin
- School of Medicine, Universidad Central del Caribe, Bayamón, PR, United States
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Plachez C, Tsytsarev V, Zhao S, Erzurumlu RS. Amyloid Deposition and Dendritic Complexity of Corticocortical Projection Cells in Five Familial Alzheimer's Disease Mouse. Neuroscience 2023; 512:85-98. [PMID: 36549605 PMCID: PMC10112867 DOI: 10.1016/j.neuroscience.2022.12.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 12/09/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
In Alzheimer's disease and related dementias, amyloid beta (Aβ) and amyloid plaques can disrupt long-term synaptic plasticity, learning and memory and cognitive function. Plaque accumulation can disrupt corticocortical circuitry leading to abnormalities in sensory, motor, and cognitive processing. In this study, using 5xFAD (five Familial Alzheimer's Disease - FAD - mutations) mice, we evaluated amyloid plaque formation in different cortical areas, and whether differential amyloid accumulation across cortical fields correlates with changes in dendritic complexity of layer 3 corticocortical projection neurons and functional responses in the primary somatosensory cortex following whisker stimulation. We focused on three cortical areas: the primary somatosensory cortex (S1), the primary motor cortex (M1), and the prefrontal cortex (PFC including the anterior cingulate, prelimbic, and infralimbic subdivisions). We found that Aβ and amyloid plaque accumulation is not uniform across 5xFAD cortical areas, while there is no expression in littermate controls. We also found that there are differential layer 3 pyramidal cell dendritic complexity changes across the three areas in 5xFAD mice, compared to same age controls, with no apparent relation to differential amyloid accumulation. We used voltage-sensitive dye imaging (VSDi) to visualize neural activity in S1, M1 and PFC following whisker activation. Control mice show normal physiological responses in all three cortical areas, whereas 5xFAD mice only display physiological responses in S1. Taken together our results show that 5xFAD mutation affects the overall dendritic morphology of layer 3 pyramidal cells across sensory-motor and association cortex irrespective of the density and distribution of the Aβ amyloid proteins. Corticocortical circuitry between the sensory and motor/association areas is most likely disrupted in 5xFAD mice as cortical responses to whisker stimulation are altered.
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Affiliation(s)
- Celine Plachez
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, 20 Penn St, HSF-2, Baltimore, 21201 MD, USA.
| | - Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, 20 Penn St, HSF-2, Baltimore, 21201 MD, USA.
| | - Shuxin Zhao
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, 20 Penn St, HSF-2, Baltimore, 21201 MD, USA.
| | - Reha S Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, 20 Penn St, HSF-2, Baltimore, 21201 MD, USA.
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Alves JM, Inyushin M, Tsytsarev V, Roldan-Kalil JA, Miranda-Valentin E, Maldonado-Martinez G, Ramos-Feliciano KM, Hunter-Mellado R. Adjuvant effect of dendritic cells activator Imiquimod in genetic immunization with HIV-1 p55 Gag. J Immunol Tech Infect Dis 2023; 12:330. [PMID: 37205236 PMCID: PMC10191261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Dendritic cells (DC) are important antigen-presenting cells that have abilities to induce and maintain T-cell immunity, or attenuate it during hyperimmunization. Additional activation of DCs may be useful for vaccination purposes. Imiquimod is known to be a specific agonist of the Toll-like receptors (TLR7), which are located mainly on DCs. To study the effect of DC stimulation on the effectiveness of an HIV-1 p55 gag DNA vaccine in a mice model, we employed 25, 50, and 100 nM of Imiquimod as an adjuvant. Subsequently, Western blot analysis was used to quantify p55 protein production after the immunization. To characterize T-cells immune response, both the frequency of IFN-γ -secreting cells and IFN-γ and IL-4 production were measured, via an ELIspot assay and ELISA, respectively. Low concentrations of Imiquimod were found to effectively stimulate Gag production and the magnitude of the T-cell immune response, whereas higher concentrations reduced vaccination effects. Our results show that the adjuvant effects of Imiquimod depend on concentration. The use of Imiquimod may be helpful to study DC to T cell communication, including possible induction of immunotolerance.
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Affiliation(s)
- Janaina M Alves
- Universidad Central del Caribe School of Medicine, Bayamón, Puerto Rico 00960
| | - Mikhail Inyushin
- Universidad Central del Caribe School of Medicine, Bayamón, Puerto Rico 00960
| | | | | | - Eric Miranda-Valentin
- University of Puerto Rico, Medical Sciences Campus School of Medicine, San Juan, Puerto Rico
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Roldan-Kalil J, Zueva L, Alves J, Tsytsarev V, Sanabria P, Inyushin M. Amount of Melanin Granules in Human Hair Defines the Absorption and Conversion to Heat of Light Energy in the Visible Spectrum. Photochem Photobiol 2022. [PMID: 36403200 DOI: 10.1111/php.13744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 11/16/2022] [Indexed: 11/22/2022]
Abstract
One of the known important functions of hair is protection from extensive sunlight. This protection is accomplished in large part due to natural hair pigmentation which is known to reflect the number of melanin granules (melanosomes) in the hair shaft, and melanin variants. Melanin takes in excessive light energy and converts it to heat in a process called absorption; heat is then dissipated into the environment as infrared radiation, thereby protecting the underlying skin. We used transmission electron microscopy (TEM) to visualize the melanosome counts in samples of human hair, and used thermal microscopy to measure the temperature changes of the samples when exposed to green and blue light lasers. In our experiments green light conversion to heat was highly correlated to the number of melanosomes, whereas blue light conversion to heat was less correlated, which may be because the reddish melanosomes it contains are less effective in absorbing energy from the blue spectrum of light. Anyway, we have shown the metals accumulation in the melanin can be easily visualized with TEM. We confirmed that the amount of melanin granules in human hair defines the conversion to heat of light energy in the visible spectrum.
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Affiliation(s)
| | - Lidia Zueva
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico
| | - Janaina Alves
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico
| | | | - Priscila Sanabria
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico
| | - Mikhail Inyushin
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico
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Tsytsarev V, Kwon SE, Plachez C, Zhao S, O'Connor DH, Erzurumlu RS. Layers 3 and 4 Neurons of the Bilateral Whisker-Barrel Cortex. Neuroscience 2022; 494:140-151. [PMID: 35598701 PMCID: PMC9884091 DOI: 10.1016/j.neuroscience.2022.05.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 05/11/2022] [Accepted: 05/13/2022] [Indexed: 01/31/2023]
Abstract
In Robo3R3-5cKO mouse brain, rhombomere 3-derived trigeminal principal nucleus (PrV) neurons project bilaterally to the somatosensory thalamus. As a consequence, whisker-specific neural modules (barreloids and barrels) representing whiskers on both sides of the face develop in the sensory thalamus and the primary somatosensory cortex. We examined the morphological complexity of layer 4 barrel cells, their postsynaptic partners in layer 3, and functional specificity of layer 3 pyramidal cells. Layer 4 spiny stellate cells form much smaller barrels and their dendritic fields are more focalized and less complex compared to controls, while layer 3 pyramidal cells did not show notable differences. Using in vivo 2-photon imaging of a genetically encoded fluorescent [Ca2+] sensor, we visualized neural activity in the normal and Robo3R3-5cKO barrel cortex in response to ipsi- and contralateral single whisker stimulation. Layer 3 neurons in control animals responded only to their contralateral whiskers, while in the mutant cortex layer 3 pyramidal neurons showed both ipsi- and contralateral whisker responses. These results indicate that bilateral whisker map inputs stimulate different but neighboring groups of layer 3 neurons which normally relay contralateral whisker-specific information to other cortical areas.
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Affiliation(s)
- Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore 20 Penn St, HSF-2, 21201 MD, Baltimore, United States.
| | - Sung E Kwon
- Department of Neuroscience, John Hopkins School of Medicine, 855 N. Wolfe Street, Rangos 295, Baltimore, MD 21205, United States.
| | - Celine Plachez
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore 20 Penn St, HSF-2, 21201 MD, Baltimore, United States.
| | - Shuxin Zhao
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore 20 Penn St, HSF-2, 21201 MD, Baltimore, United States.
| | - Daniel H O'Connor
- Department of Neuroscience and Krieger Mind/Brain Institute Johns Hopkins University, 3400 N Charles St, 338 Krieger Hall, Baltimore, MD 21218, United States.
| | - Reha S Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore 20 Penn St, HSF-2, 21201 MD, Baltimore, United States.
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Zueva L, Zayas-Santiago A, Rojas L, Sanabria P, Alves J, Tsytsarev V, Inyushin M. Multilayer subwavelength gratings or sandwiches with periodic structure shape light reflection in the tapetum lucidum of taxonomically diverse vertebrate animals. J Biophotonics 2022; 15:e202200002. [PMID: 35243792 PMCID: PMC9487202 DOI: 10.1002/jbio.202200002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 02/09/2022] [Accepted: 02/24/2022] [Indexed: 06/14/2023]
Abstract
Eye shine in the dark has attracted many researchers to the field of eye optics, but the initial studies of subwavelength arrangements in tapetum began only with the development of electronic microscopy at the end of the 20th century. As a result of a number of studies, it was shown that the reflective properties of the tapetum are due to their specialized cellular subwavelength microstructure (photonic crystals). These properties, together with the mutual orientation of the crystals, lead to a significant increase in reflection, which, in turn, enhances the sensitivity of the eye. In addition, research confirmed that optical mechanisms of reflection in the tapetum are very similar even for widely separated species. Due to progress in the field of nano-optics, researchers now have a better understanding of the main principles of this phenomenon. In this review, we summarize electron microscopic and functional studies of tapetal structures in the main vertebrate classes. This allows data on the microstructure of the tapetum to be used to improve our understanding of the visual system.
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Affiliation(s)
- Lidia Zueva
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico, USA
| | | | - Legier Rojas
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico, USA
| | - Priscila Sanabria
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico, USA
| | - Janaina Alves
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico, USA
| | | | - Mikhail Inyushin
- Universidad Central del Caribe School of Medicine, Bayamon, Puerto Rico, USA
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Tsytsarev V. Methodological aspects of studying the mechanisms of consciousness. Behav Brain Res 2022; 419:113684. [PMID: 34838578 DOI: 10.1016/j.bbr.2021.113684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 11/21/2021] [Accepted: 11/22/2021] [Indexed: 11/24/2022]
Abstract
There are at least two approaches to the definition of consciousness. In the first case, certain aspects of consciousness, called qualia, are considered inaccessible for research from a third person and can only be described through subjective experience. This approach is inextricably linked with the so-called "hard problem of consciousness", that is, the question of why consciousness has qualia or how any physical changes in the environment can generate subjective experience. With this approach, some aspects of consciousness, by definition, cannot be explained on the basis of external observations and, therefore, are outside the scope of scientific research. In the second case, a priori constraints do not constrain the field of scientific investigation, and the best explanation of the experience in the first person is included as a possible subject of empirical research. Historically, in the study of cause-and-effect relationships in biology, it was customary to distinguish between proximate causation and ultimate causation existing in biological systems. Immediate causes are based on the immediate influencing factors [1]. Proximate causation has evolutionary explanations. When studying biological systems themselves, such an approach is undoubtedly justified, but it often seems insufficient when studying the interaction of consciousness and the brain [2,3]. Current scientific communities proceed from the assumption that the physical substrate for the generation of consciousness is a neural network that unites various types of neurons located in various brain structures. Many neuroscientists attach a key role in this process to the cortical and thalamocortical neural networks. This question is directly related to experimental and clinical research in the field of disorder of consciousness. Progress in this area of medicine depends on advances in neuroscience in this area and is also a powerful source of empirical information. In this area of consciousness research, a large amount of experimental data has been accumulated, and in this review an attempt was made to generalize and systematize.
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Volnova A, Tsytsarev V, Ganina O, Vélez-Crespo GE, Alves JM, Ignashchenkova A, Inyushin M. The Anti-Epileptic Effects of Carbenoxolone In Vitro and In Vivo. Int J Mol Sci 2022; 23:ijms23020663. [PMID: 35054848 PMCID: PMC8775396 DOI: 10.3390/ijms23020663] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 01/04/2022] [Accepted: 01/06/2022] [Indexed: 12/14/2022] Open
Abstract
Gap junctions (GJs) are intercellular junctions that allow the direct transfer of ions and small molecules between neighboring cells, and GJs between astrocytes play an important role in the development of various pathologies of the brain, including regulation of the pathological neuronal synchronization underlying epileptic seizures. Recently, we found that a pathological change is observed in astrocytes during the ictal and interictal phases of 4-aminopyridin (4-AP)-elicited epileptic activity in vitro, which was correlated with neuronal synchronization and extracellular epileptic electrical activity. This finding raises the question: Does this signal depend on GJs between astrocytes? In this study we investigated the effect of the GJ blocker, carbenoxolone (CBX), on epileptic activity in vitro and in vivo. Based on the results obtained, we came to the conclusion that the astrocytic syncytium formed by GJ-associated astrocytes, which is responsible for the regulation of potassium, affects the formation of epileptic activity in astrocytes in vitro and epileptic seizure onset. This effect is probably an important, but not the only, mechanism by which CBX suppresses epileptic activity. It is likely that the mechanisms of selective inhibition of GJs between astrocytes will show important translational benefits in anti-epileptic therapies.
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Affiliation(s)
- Anna Volnova
- Biological Faculty, Saint Petersburg State University, 199034 St. Petersburg, Russia
- Institute of Translational Biomedicine, Saint Petersburg State University, 199034 St. Petersburg, Russia;
- Correspondence: (A.V.); (M.I.)
| | | | - Olga Ganina
- Nevsky Center of Scientific Collaboration, 192119 St. Petersburg, Russia;
| | - Grace E. Vélez-Crespo
- School of Medicine, Universidad Central del Caribe, Bayamon, PR 00956, USA; (G.E.V.-C.); (J.M.A.)
| | - Janaina M. Alves
- School of Medicine, Universidad Central del Caribe, Bayamon, PR 00956, USA; (G.E.V.-C.); (J.M.A.)
| | - Alla Ignashchenkova
- Institute of Translational Biomedicine, Saint Petersburg State University, 199034 St. Petersburg, Russia;
- Nevsky Center of Scientific Collaboration, 192119 St. Petersburg, Russia;
| | - Mikhail Inyushin
- School of Medicine, Universidad Central del Caribe, Bayamon, PR 00956, USA; (G.E.V.-C.); (J.M.A.)
- Correspondence: (A.V.); (M.I.)
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14
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Chen Z, Tsytsarev V, Finfrock YZ, Antipova OA, Cai Z, Arakawa H, Lischka FW, Hooks BM, Wilton R, Wang D, Liu Y, Gaitan B, Tao Y, Chen Y, Erzurumlu RS, Yang H, Rozhkova EA. Wireless Optogenetic Modulation of Cortical Neurons Enabled by Radioluminescent Nanoparticles. ACS Nano 2021; 15:5201-5208. [PMID: 33625219 DOI: 10.1021/acsnano.0c10436] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
While offering high-precision control of neural circuits, optogenetics is hampered by the necessity to implant fiber-optic waveguides in order to deliver photons to genetically engineered light-gated neurons in the brain. Unlike laser light, X-rays freely pass biological barriers. Here we show that radioluminescent Gd2(WO4)3:Eu nanoparticles, which absorb external X-rays energy and then downconvert it into optical photons with wavelengths of ∼610 nm, can be used for the transcranial stimulation of cortical neurons expressing red-shifted, ∼590-630 nm, channelrhodopsin ReaChR, thereby promoting optogenetic neural control to the practical implementation of minimally invasive wireless deep brain stimulation.
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Affiliation(s)
- Zhaowei Chen
- Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
- Institute of Food Safety and Environment Monitoring, MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou 350108, People's Republic of China
| | - Vassiliy Tsytsarev
- Fischell Department of Bioengineering, University of Maryland, 8228 Paint Branch Drive, College Park, Maryland 20742, United States
| | - Y Zou Finfrock
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
- Science Division, Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, Saskatchewan S7N 2 V3, Canada
| | - Olga A Antipova
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Zhonghou Cai
- Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Hiroyuki Arakawa
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, Baltimore, Maryland 21201, United States
| | - Fritz W Lischka
- Biomedical Instrumentation Center, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, Maryland 20814-4799, United States
| | - Bryan M Hooks
- Department of Neurobiology, University of Pittsburgh, 3500 Terrace Street, Suite W1458, Pittsburgh, Pennsylvania 15213-2500, United States
| | - Rosemarie Wilton
- Biosciences, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Dongyi Wang
- Fischell Department of Bioengineering, University of Maryland, 8228 Paint Branch Drive, College Park, Maryland 20742, United States
| | - Yi Liu
- Fischell Department of Bioengineering, University of Maryland, 8228 Paint Branch Drive, College Park, Maryland 20742, United States
| | - Brandon Gaitan
- Fischell Department of Bioengineering, University of Maryland, 8228 Paint Branch Drive, College Park, Maryland 20742, United States
| | - Yang Tao
- Fischell Department of Bioengineering, University of Maryland, 8228 Paint Branch Drive, College Park, Maryland 20742, United States
| | - Yu Chen
- Fischell Department of Bioengineering, University of Maryland, 8228 Paint Branch Drive, College Park, Maryland 20742, United States
| | - Reha S Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, Baltimore, Maryland 21201, United States
| | - Huanghao Yang
- Institute of Food Safety and Environment Monitoring, MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou 350108, People's Republic of China
| | - Elena A Rozhkova
- Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
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15
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Tang Q, Tsytsarev V, Yan F, Wang C, Erzurumlu RS, Chen Y. In vivo voltage-sensitive dye imaging of mouse cortical activity with mesoscopic optical tomography. Neurophotonics 2020; 7:041402. [PMID: 33274250 PMCID: PMC7708784 DOI: 10.1117/1.nph.7.4.041402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 11/11/2020] [Indexed: 05/11/2023]
Abstract
Significance: Cellular layering is a hallmark of the mammalian neocortex with layer and cell type-specific connections within the cortical mantle and subcortical connections. A key challenge in studying circuit function within the neocortex is to understand the spatial and temporal patterns of information flow between different columns and layers. Aim: We aimed to investigate the three-dimensional (3D) layer- and area-specific interactions in mouse cortex in vivo. Approach: We applied a new promising neuroimaging method-fluorescence laminar optical tomography in combination with voltage-sensitive dye imaging (VSDi). VSDi is a powerful technique for interrogating membrane potential dynamics in assemblies of cortical neurons, but it is traditionally used for two-dimensional (2D) imaging. Our mesoscopic technique allows visualization of neuronal activity in a 3D manner with high temporal resolution. Results: We first demonstrated the depth-resolved capability of 3D mesoscopic imaging technology in Thy1-ChR2-YFP transgenic mice. Next, we recorded the long-range functional projections between sensory cortex (S1) and motor cortex (M1) in mice, in vivo, following single whisker deflection. Conclusions: The results show that mesoscopic imaging technique has the potential to investigate the layer-specific neural connectivity in the mouse cortex in vivo. Combination of mesoscopic imaging technique with optogenetic control strategy is a promising platform for determining depth-resolved interactions between cortical circuit elements.
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Affiliation(s)
- Qinggong Tang
- University of Oklahoma, Stephenson School of Biomedical Engineering, Norman, Oklahoma, United States
- University of Maryland, Fischell Department of Bioengineering, College Park, Maryland, United States
- Address all correspondence to Qinggong Tang, ; Reha S. Erzurumlu, ; Yu Chen,
| | - Vassiliy Tsytsarev
- University of Maryland School of Medicine, Department of Anatomy and Neurobiology, Baltimore, Maryland, United States
| | - Feng Yan
- University of Oklahoma, Stephenson School of Biomedical Engineering, Norman, Oklahoma, United States
| | - Chen Wang
- University of Oklahoma, Stephenson School of Biomedical Engineering, Norman, Oklahoma, United States
| | - Reha S. Erzurumlu
- University of Maryland School of Medicine, Department of Anatomy and Neurobiology, Baltimore, Maryland, United States
- Address all correspondence to Qinggong Tang, ; Reha S. Erzurumlu, ; Yu Chen,
| | - Yu Chen
- University of Maryland, Fischell Department of Bioengineering, College Park, Maryland, United States
- University of Massachusetts, Department of Biomedical Engineering, Amherst, Massachusetts, United States
- Address all correspondence to Qinggong Tang, ; Reha S. Erzurumlu, ; Yu Chen,
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16
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Mueller BJ, Zhdanov AV, Borisov SM, Foley T, Okkelman IA, Tsytsarev V, Tang Q, Erzurumlu RS, Chen Y, Zhang H, Toncelli C, Klimant I, Papkovsky DB, Dmitriev RI. Nanoparticle-based fluoroionophore for analysis of potassium ion dynamics in 3D tissue models and in vivo. Adv Funct Mater 2018; 28:1704598. [PMID: 30271316 PMCID: PMC6157274 DOI: 10.1002/adfm.201704598] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The imaging of real-time fluxes of K+ ions in live cell with high dynamic range (5-150 mM) is of paramount importance for neuroscience and physiology of the gastrointestinal tract, kidney and other tissues. In particular, the research on high-performance deep-red fluorescent nanoparticle-based biosensors is highly anticipated. We found that BODIPY-based FI3 K+-sensitive fluoroionophore encapsulated in cationic polymer RL100 nanoparticles displays unusually strong efficiency in staining of broad spectrum of cell models, such as primary neurons and intestinal organoids. Using comparison of brightness, photostability and fluorescence lifetime imaging microscopy (FLIM) we confirmed that FI3 nanoparticles display distinctively superior intracellular staining compared to the free dye. We evaluated FI3 nanoparticles in real-time live cell imaging and found that it is highly useful for monitoring intra- and extracellular K+ dynamics in cultured neurons. Proof-of-concept in vivo brain imaging confirmed applicability of the biosensor for visualization of epileptic seizures. Collectively, this data makes fluoroionophore FI3 a versatile cross-platform fluorescent biosensor, broadly compatible with diverse experimental models and that crown ether-based polymer nanoparticles can provide a new venue for design of efficient fluorescent probes.
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Affiliation(s)
- Bernhard J. Mueller
- Institute of Analytical Chemistry and Food Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Alexander V. Zhdanov
- ABCRF, School of Biochemistry and Cell biology, University College Cork, Cork, Ireland
| | - Sergey M. Borisov
- Institute of Analytical Chemistry and Food Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Tara Foley
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Irina A. Okkelman
- ABCRF, School of Biochemistry and Cell biology, University College Cork, Cork, Ireland
| | - Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Qinggong Tang
- Fischell Department of Bioengineering, University of Maryland, College Park, 20740 MD, USA
| | - Reha S. Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Yu Chen
- Fischell Department of Bioengineering, University of Maryland, College Park, 20740 MD, USA
| | - Haijiang Zhang
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles, Lerchenfeldstrasse 5, CH-9014 St. Gallen, Switzerland
| | - Claudio Toncelli
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles, Lerchenfeldstrasse 5, CH-9014 St. Gallen, Switzerland
| | - Ingo Klimant
- Institute of Analytical Chemistry and Food Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Dmitri B. Papkovsky
- ABCRF, School of Biochemistry and Cell biology, University College Cork, Cork, Ireland
| | - Ruslan I. Dmitriev
- ABCRF, School of Biochemistry and Cell biology, University College Cork, Cork, Ireland
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17
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Lee LJ, Tsytsarev V, Erzurumlu RS. Structural and functional differences in the barrel cortex of Mecp2 null mice. J Comp Neurol 2017; 525:3951-3961. [PMID: 28857161 DOI: 10.1002/cne.24315] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 07/28/2017] [Accepted: 08/14/2017] [Indexed: 02/06/2023]
Abstract
Functional deficits in sensory systems are commonly noted in neurodevelopmental disorders, such as the Rett syndrome (RTT). Defects in methyl CpG binding protein gene (MECP2) largely accounts for RTT. Manipulations of the Mecp2 gene in mice provide useful models to probe into various aspects of brain development associated with the RTT. In this study, we focused on the somatosensory cortical phenotype in the Bird mouse model of RTT. We used voltage-sensitive dye imaging to evaluate whisker sensory evoked activity in the barrel cortex of mice. We coupled this functional assay with morphological analyses in postnatal mice and investigated the dendritic differentiation of barrel neurons and individual thalamocortical axon (TCA) arbors that synapse with them. We show that in Mecp2-deficient male mice, whisker-evoked activity is roughly topographic but weak in the barrel cortex. At the morphological level, we find that TCA arbors fail to develop into discrete, concentrated patches in barrel hollows, and the complexity of the dendritic branches in layer IV spiny stellate neurons is reduced. Collectively, our results indicate significant structural and functional impairments in the barrel cortex of the Bird mouse line, a popular animal model for the RTT. Such structural and functional anomalies in the primary somatosensory cortex may underlie orofacial tactile sensitivity issues and sensorimotor stereotypies characteristic of RTT.
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Affiliation(s)
- Li-Jen Lee
- Graduate Institute of Anatomy and Cell Biology, National Taiwan University, Taipei, Taiwan, ROC.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Reha S Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland
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18
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Kwon SE, Tsytsarev V, Erzurumlu RS, O'Connor DH. Organization of orientation-specific whisker deflection responses in layer 2/3 of mouse somatosensory cortex. Neuroscience 2017; 368:46-56. [PMID: 28827090 DOI: 10.1016/j.neuroscience.2017.07.067] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 07/24/2017] [Accepted: 07/27/2017] [Indexed: 11/18/2022]
Abstract
The rodent whisker-barrel system is characterized by its patterned somatotopic mapping between the sensory periphery and multiple regions of the brain. While somatotopy in the whisker system is established, we know far less about how preferences for stimulus orientation or other features are organized. Mouse somatosensation is an increasingly popular model for circuit-based dissection of perceptual decision making and learning, yet our understanding of how stimulus feature representations are organized in the cortex is incomplete. Here, we used in vivo two-photon calcium imaging to monitor activity of populations of layer (L) 2/3 neurons in the mouse primary somatosensory cortex during deflections of a single whisker in two orthogonal orientations (azimuthal or elevational). We split the population response to whisker deflections into an orientation-specific component and a non-specific component that reflected overall excitability in response to deflection of a single whisker. Orientation-specific responses were organized in a locally heterogeneous and spatially distributed manner. Correlations in the stimulus-independent trial-to-trial variability of pairs of neurons were higher among neurons that preferred the same orientation. These correlations depended on similarity in both orientation-specific and non-specific components of responses to single-whisker deflections. Our results shed light on L2/3 organization in mouse somatosensory cortex, and lay a foundation for dissecting circuit mechanisms of perceptual learning and decision-making during orientation discrimination tasks.
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Affiliation(s)
- Sung Eun Kwon
- The Solomon H. Snyder Department of Neuroscience, Kavli Neuroscience Discovery Institute, Brain Science Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Reha S Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Daniel H O'Connor
- The Solomon H. Snyder Department of Neuroscience, Kavli Neuroscience Discovery Institute, Brain Science Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, United States.
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19
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Nag OK, Stewart MH, Deschamps JR, Susumu K, Oh E, Tsytsarev V, Tang Q, Efros AL, Vaxenburg R, Black BJ, Chen Y, O’Shaughnessy TJ, North SH, Field LD, Dawson PE, Pancrazio JJ, Medintz IL, Chen Y, Erzurumlu RS, Huston AL, Delehanty JB. Quantum Dot-Peptide-Fullerene Bioconjugates for Visualization of in Vitro and in Vivo Cellular Membrane Potential. ACS Nano 2017; 11:5598-5613. [PMID: 28514167 PMCID: PMC6001310 DOI: 10.1021/acsnano.7b00954] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We report the development of a quantum dot (QD)-peptide-fullerene (C60) electron transfer (ET)-based nanobioconjugate for the visualization of membrane potential in living cells. The bioconjugate is composed of (1) a central QD electron donor, (2) a membrane-inserting peptidyl linker, and (3) a C60 electron acceptor. The photoexcited QD donor engages in ET with the C60 acceptor, resulting in quenching of QD photoluminescence (PL) that tracks positively with the number of C60 moieties arrayed around the QD. The nature of the QD-capping ligand also modulates the quenching efficiency; a neutral ligand coating facilitates greater QD quenching than a negatively charged carboxylated ligand. Steady-state photophysical characterization confirms an ET-driven process between the donor-acceptor pair. When introduced to cells, the amphiphilic QD-peptide-C60 bioconjugate labels the plasma membrane by insertion of the peptide-C60 portion into the hydrophobic bilayer, while the hydrophilic QD sits on the exofacial side of the membrane. Depolarization of cellular membrane potential augments the ET process, which is manifested as further quenching of QD PL. We demonstrate in HeLa cells, PC12 cells, and primary cortical neurons significant QD PL quenching (ΔF/F0 of 2-20% depending on the QD-C60 separation distance) in response to membrane depolarization with KCl. Further, we show the ability to use the QD-peptide-C60 probe in combination with conventional voltage-sensitive dyes (VSDs) for simultaneous two-channel imaging of membrane potential. In in vivo imaging of cortical electrical stimulation, the optical response of the optimal QD-peptide-C60 configuration exhibits temporal responsivity to electrical stimulation similar to that of VSDs. Notably, however, the QD-peptide-C60 construct displays 20- to 40-fold greater ΔF/F0 than VSDs. The tractable nature of the QD-peptide-C60 system offers the advantages of ease of assembly, large ΔF/F0, enhanced photostability, and high throughput without the need for complicated organic synthesis or genetic engineering, respectively, that is required of traditional VSDs and fluorescent protein constructs.
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Affiliation(s)
- Okhil K. Nag
- Center for Bio/Molecular Science and Engineering, Code 6900
| | | | | | - Kimihiro Susumu
- Optical Sciences Division, Code 5600
- Sotera Defense Solutions, Columbia, Maryland 21046, United States
| | - Eunkeu Oh
- Optical Sciences Division, Code 5600
- Sotera Defense Solutions, Columbia, Maryland 21046, United States
| | - Vassiliy Tsytsarev
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Qinggong Tang
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - Alexander L. Efros
- Materials and Science and Technology Division, Code 6300, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Roman Vaxenburg
- Computational Materials Science Center, George Mason University, Fairfax, Virginia 22030, United States
| | - Bryan J. Black
- Department of Bioengineering, University of Texas at Dallas, Richardson, Texas 75080, United States
| | - YungChia Chen
- Center for Bio/Molecular Science and Engineering, Code 6900
| | - Thomas J. O’Shaughnessy
- Materials and Science and Technology Division, Code 6300, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
| | | | - Lauren D. Field
- Center for Bio/Molecular Science and Engineering, Code 6900
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - Philip E. Dawson
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Joseph J. Pancrazio
- Department of Bioengineering, University of Texas at Dallas, Richardson, Texas 75080, United States
| | | | - Yu Chen
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - Reha S. Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
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20
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Tang Q, Liu Y, Tsytsarev V, Lin J, Wang B, Kanniyappan U, Li Z, Chen Y. High-dynamic-range fluorescence laminar optical tomography (HDR-FLOT). Biomed Opt Express 2017; 8:2124-2137. [PMID: 28736659 PMCID: PMC5516817 DOI: 10.1364/boe.8.002124] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 02/16/2017] [Accepted: 03/04/2017] [Indexed: 05/21/2023]
Abstract
Three-dimensional fluorescence laminar optical tomography (FLOT) can achieve resolutions of 100-200 µm and penetration depths of 2-3 mm. FLOT has been used in tissue engineering, neuroscience, as well as oncology. The limited dynamic range of the charge-coupled device-based system makes it difficult to image fluorescent samples with a large concentration difference, limits its penetration depth, and diminishes the quantitative accuracy of 3D reconstruction data. Here, incorporating the high-dynamic-range (HDR) method widely used in digital cameras, we present HDR-FLOT, increasing penetration depth and improving the ability to image fluorescent samples with a large concentration difference. The method was tested using an agar phantom and a B6 mouse for brain imaging in vivo.
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Affiliation(s)
- Qinggong Tang
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
- Contributed equally
| | - Yi Liu
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
- Contributed equally
| | - Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Jonathan Lin
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
| | - Bohan Wang
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
| | - Udayakumar Kanniyappan
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
| | - Zhifang Li
- Key Laboratory of Optoelectronic Science and Technology for Medicine, Ministry of Education, College of Photonic and Electronic Engineering, Fujian Normal University, Fuzhou 350007, China
| | - Yu Chen
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
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21
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Tsytsarev V, Akkentli F, Pumbo E, Tang Q, Chen Y, Erzurumlu RS, Papkovsky DB. Planar implantable sensor for in vivo measurement of cellular oxygen metabolism in brain tissue. J Neurosci Methods 2017; 281:1-6. [PMID: 28219725 DOI: 10.1016/j.jneumeth.2017.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/13/2017] [Accepted: 02/15/2017] [Indexed: 10/20/2022]
Abstract
BACKGROUND Brain imaging methods are continually improving. Imaging of the cerebral cortex is widely used in both animal experiments and charting human brain function in health and disease. Among the animal models, the rodent cerebral cortex has been widely used because of patterned neural representation of the whiskers on the snout and relative ease of activating cortical tissue with whisker stimulation. NEW METHOD We tested a new planar solid-state oxygen sensor comprising a polymeric film with a phosphorescent oxygen-sensitive coating on the working side, to monitor dynamics of oxygen metabolism in the cerebral cortex following sensory stimulation. RESULTS Sensory stimulation led to changes in oxygenation and deoxygenation processes of activated areas in the barrel cortex. We demonstrate the possibility of dynamic mapping of relative changes in oxygenation in live mouse brain tissue with such a sensor. COMPARISON WITH EXISTING METHOD Oxygenation-based functional magnetic resonance imaging (fMRI) is very effective method for functional brain mapping but have high costs and limited spatial resolution. Optical imaging of intrinsic signal (IOS) does not provide the required sensitivity, and voltage-sensitive dye optical imaging (VSDi) has limited applicability due to significant toxicity of the voltage-sensitive dye. Our planar solid-state oxygen sensor imaging approach circumvents these limitations, providing a simple optical contrast agent with low toxicity and rapid application. CONCLUSIONS The planar solid-state oxygen sensor described here can be used as a tool in visualization and real-time analysis of sensory-evoked neural activity in vivo. Further, this approach allows visualization of local neural activity with high temporal and spatial resolution.
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Affiliation(s)
- Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, HSF-2, 21201 MD, Baltimore, USA.
| | - Fatih Akkentli
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, HSF-2, 21201 MD, Baltimore, USA.
| | - Elena Pumbo
- Center for Genetic Medicine, Children's National Medical Center, Washington DC, 111 Michigan Avenue, NW Washington, DC 20010, USA.
| | - Qinggong Tang
- Fischell Department of Bioengineering, University of Maryland, College Park, Kim Engineering Building, College Park, MD 20740, USA.
| | - Yu Chen
- Fischell Department of Bioengineering, University of Maryland, College Park, Kim Engineering Building, College Park, MD 20740, USA.
| | - Reha S Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, HSF-2, 21201 MD, Baltimore, USA.
| | - Dmitri B Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building 1.28, College Road, Cork, Ireland.
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Nikzad S, Chen Y, Tsytsarev V, Kateb B, Grundfest W. Special Section Guest Editorial: Brain Mapping and Therapeutics. Neurophotonics 2017; 4:011001. [PMID: 28401171 PMCID: PMC5377230 DOI: 10.1117/1.nph.4.1.011001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Affiliation(s)
- Shouleh Nikzad
- Jet Propulsion Laboratory, California Institute of Technology, Medical Engineering Forum, Advanced Detectors, Systems and Nanoscience Group, and, California Institute of Technology, Medical Engineering Department, and, Physics, Math, and Astronomy Division, 4800 Oak Grove Drive, Pasadena, California 91109
| | - Yu Chen
- University of Maryland, FISCHELL Department of Bioengineering, 3142 Jeong H. Kim Engineering Building, College Park, Maryland 20742
| | - Vassiliy Tsytsarev
- University of Maryland School of Medicine, Department of Anatomy and Neurobiology, 20 Penn Street, HSF-2, Baltimore, Maryland 21201
| | - Babak Kateb
- Society for Brain Mapping & Therapeutics (SBMT), and, Brain Mapping Foundation (BMF), and, National Center for NanoBioElectronics (NCNBE), and, California Neurosurgical Institute (CNI), 8159 Santa Monica Blvd. # 200, West Hollywood, CA 90046
| | - Warren Grundfest
- Department of Bioengineering, Department of Electrical Engineering, UCLA School of Engineering, and, Department of Surgery, UCLA David Geffen School of Medicine, 420 Westwood Plaza 5121 Engineering V, Los Angeles, CA 90095
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Tang Q, Lin J, Tsytsarev V, Erzurumlu RS, Liu Y, Chen Y. Review of mesoscopic optical tomography for depth-resolved imaging of hemodynamic changes and neural activities. Neurophotonics 2017; 4:011009. [PMID: 27990452 PMCID: PMC5108095 DOI: 10.1117/1.nph.4.1.011009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 10/19/2016] [Indexed: 05/18/2023]
Abstract
Understanding the functional wiring of neural circuits and their patterns of activation following sensory stimulations is a fundamental task in the field of neuroscience. Furthermore, charting the activity patterns is undoubtedly important to elucidate how neural networks operate in the living brain. However, optical imaging must overcome the effects of light scattering in the tissue, which limit the light penetration depth and affect both the imaging quantitation and sensitivity. Laminar optical tomography (LOT) is a three-dimensional (3-D) in-vivo optical imaging technique that can be used for functional imaging. LOT can achieve both a resolution of 100 to [Formula: see text] and a penetration depth of 2 to 3 mm based either on absorption or fluorescence contrast, as well as large field-of-view and high acquisition speed. These advantages make LOT suitable for 3-D depth-resolved functional imaging of the neural functions in the brain and spinal cords. We review the basic principles and instrumentations of representative LOT systems, followed by recent applications of LOT on 3-D imaging of neural activities in the rat forepaw stimulation model and mouse whisker-barrel system.
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Affiliation(s)
- Qinggong Tang
- University of Maryland, Fischell Department of Bioengineering, 2334 Jeong H. Kim Engineering Building, College Park, Maryland 20742, United States
| | - Jonathan Lin
- University of Maryland, Fischell Department of Bioengineering, 2334 Jeong H. Kim Engineering Building, College Park, Maryland 20742, United States
| | - Vassiliy Tsytsarev
- University of Maryland School of Medicine, Department of Anatomy and Neurobiology, 20 Penn Street, HSFII S251, Baltimore, Maryland 21201, United States
| | - Reha S. Erzurumlu
- University of Maryland School of Medicine, Department of Anatomy and Neurobiology, 20 Penn Street, HSFII S251, Baltimore, Maryland 21201, United States
| | - Yi Liu
- University of Maryland, Fischell Department of Bioengineering, 2334 Jeong H. Kim Engineering Building, College Park, Maryland 20742, United States
| | - Yu Chen
- University of Maryland, Fischell Department of Bioengineering, 2334 Jeong H. Kim Engineering Building, College Park, Maryland 20742, United States
- Address all correspondence to: Yu Chen, E-mail:
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Gottschalk S, Fehm TF, Deán-Ben XL, Tsytsarev V, Razansky D. Correlation between volumetric oxygenation responses and electrophysiology identifies deep thalamocortical activity during epileptic seizures. Neurophotonics 2017; 4:011007. [PMID: 27725948 PMCID: PMC5050254 DOI: 10.1117/1.nph.4.1.011007] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 09/13/2016] [Indexed: 05/05/2023]
Abstract
Visualization of whole brain activity during epileptic seizures is essential for both fundamental research into the disease mechanisms and the development of efficient treatment strategies. It has been previously discussed that pathological synchronization originating from cortical areas may reinforce backpropagating signaling from the thalamic neurons, leading to massive seizures through enhancement of high frequency neural activity in the thalamocortical loop. However, the study of deep brain neural activity is challenging with the existing functional neuroimaging methods due to lack of adequate spatiotemporal resolution or otherwise insufficient penetration into subcortical areas. To investigate the role of thalamocortical activity during epileptic seizures, we developed a new functional neuroimaging framework based on spatiotemporal correlation of volumetric optoacoustic hemodynamic responses with the concurrent electroencephalogram recordings and anatomical brain landmarks. The method is shown to be capable of accurate three-dimensional mapping of the onset, spread, and termination of the epileptiform events in a 4-aminopyridine acute model of focal epilepsy. Our study is the first to demonstrate entirely noninvasive real-time visualization of synchronized epileptic foci in the whole mouse brain, including the neocortex and subcortical structures, thus opening new vistas in systematic studies toward the understanding of brain signaling and the origins of neurological disorders.
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Affiliation(s)
- Sven Gottschalk
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
| | - Thomas Felix Fehm
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
- Technical University of Munich, Faculty of Medicine, Ismaninger Str. 22, 81675 Munich, Germany
| | - Xose Luís Deán-Ben
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
| | - Vassiliy Tsytsarev
- University of Maryland School of Medicine, Department of Anatomy and Neurobiology, 20 Penn Street, HSF II, Baltimore, Maryland 21201, United States
| | - Daniel Razansky
- Institute for Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
- Technical University of Munich, Faculty of Medicine, Ismaninger Str. 22, 81675 Munich, Germany
- Address all correspondence to: Daniel Razansky, E-mail:
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Tsytsarev V, Pumbo E, Tang Q, Chen CW, Kalchenko V, Chen Y. Study of the cortical representation of whisker frequency selectivity using voltage-sensitive dye optical imaging. Intravital 2016; 5:e1142637. [PMID: 28243518 DOI: 10.1080/21659087.2016.1142637] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 01/06/2016] [Accepted: 01/08/2016] [Indexed: 12/17/2022]
Abstract
The facial whiskers of rodents act as a high-resolution tactile apparatus that allow the animal to detect the finest details of its environment. Previously it was shown that whisker-sensitive neurons in the somatosensory cortex show frequency selectivity to small amplitude stimuli, An intravital voltage-sensitive dye optical imaging (VSDi) method in combination with the different frequency whisker stimulation was used in order to visualize neural activity in the mice somatosensory cortex in response to the stimulation of a single whisker by different frequencies. Using the intravital voltage-sensitive dye optical imaging (VSDi) method in combination with the different frequency whisker stimulation we visualized neural activity in the mice somatosensory cortex in response to the stimulation of a single whisker by different frequencies. We found that whisker stimuli with different frequencies led to different optical signals in the barrel field. Our results provide evidence that different neurons of the barrel cortex have different frequency preferences. This supports prior research that whisker deflections cause responses in cortical neurons within the barrel field according to the frequency of the stimulation. Many studies of the whisker frequency selectivity were performed using unit recording but to map spatial organization, imaging methods are essential. In the work described in the present paper, we take a serious step toward detailed functional mapping of the somatosensory cortex using VSDi. To our knowledge, this is the first demonstration of whisker frequency sensitivity and selectivity of barrel cortex neurons with optical imaging methods.
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Affiliation(s)
- Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine , Baltimore, MD, USA
| | - Elena Pumbo
- Center for Genetic Medicine, Children's National Medical Center , Washington, DC, USA
| | - Qinggong Tang
- Department of Bioengineering, University of Maryland , College Park, MD, USA
| | - Chao-Wei Chen
- Department of Bioengineering, University of Maryland , College Park, MD, USA
| | - Vyacheslav Kalchenko
- Department of Veterinary Resources, Weizmann Institute of Science , Rehovot, Israel
| | - Yu Chen
- Department of Bioengineering, University of Maryland , College Park, MD, USA
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Tang Q, Tsytsarev V, Liang CP, Akkentli F, Erzurumlu RS, Chen Y. In Vivo Voltage-Sensitive Dye Imaging of Subcortical Brain Function. Sci Rep 2015; 5:17325. [PMID: 26612326 PMCID: PMC4661443 DOI: 10.1038/srep17325] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 10/28/2015] [Indexed: 12/29/2022] Open
Abstract
The whisker system of rodents is an excellent model to study peripherally evoked neural activity in the brain. Discrete neural modules represent each whisker in the somatosensory cortex (“barrels”), thalamus (“barreloids”), and brain stem (“barrelettes”). Stimulation of a single whisker evokes neural activity sequentially in its corresponding barrelette, barreloid, and barrel. Conventional optical imaging of functional activation in the brain is limited to surface structures such as the cerebral cortex. To access subcortical structures and image sensory-evoked neural activity, we designed a needle-based optical system using gradient-index (GRIN) rod lens. We performed voltage-sensitive dye imaging (VSDi) with GRIN rod lens to visualize neural activity evoked in the thalamic barreloids by deflection of whiskers in vivo. We stimulated several whiskers together to determine the sensitivity of our approach in differentiating between different barreloid responses. We also carried out stimulation of different whiskers at different times. Finally, we used muscimol in the barrel cortex to silence the corticothalamic inputs while imaging in the thalamus. Our results show that it is possible to obtain functional maps of the sensory periphery in deep brain structures such as the thalamic barreloids. Our approach can be broadly applicable to functional imaging of other core brain structures.
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Affiliation(s)
- Qinggong Tang
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
| | - Vassiliy Tsytsarev
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA.,Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Chia-Pin Liang
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
| | - Fatih Akkentli
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Reha S Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Yu Chen
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742 USA
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Tsytsarev V, Liao LD, Kong KV, Liu YH, Erzurumlu RS, Olivo M, Thakor NV. Recent progress in voltage-sensitive dye imaging for neuroscience. J Nanosci Nanotechnol 2014; 14:4733-4744. [PMID: 24757943 DOI: 10.1166/jnn.2014.9531] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Voltage-sensitive dye imaging (VSDi) enables visualization of information processing in different areas of the brain with reasonable spatial and temporal resolution. VSDi employs different chemical compounds to transduce neural activity directly into the changes in intrinsic optical signal. Physically, voltage-sensitive dyes (VSDs) are chemical probes that reside in the neural membrane and change their fluorescence or absorbance in response to membrane potential changes. Based on these features, VSDs can be divided into two groups-absorbance and fluorescence. The spatial and temporal resolution of the VSDi is limited mainly by the technical characteristics of the optical imaging setup (e.g., computer and light-sensitive device-charge-coupled device (CCD) camera or photodiode array). In this article, we briefly review the development of the VSD, technique of VSDi and applications in functional brain imaging.
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Lo FS, Akkentli F, Tsytsarev V, Erzurumlu RS. Functional significance of cortical NMDA receptors in somatosensory information processing. J Neurophysiol 2013; 110:2627-36. [PMID: 24047907 DOI: 10.1152/jn.00052.2013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
N-methyl-d-aspartate receptor (NMDAR)-mediated activity is required for whisker-related neural patterning in the rodent brain. Deletion of the essential NMDAR subunit NR1 gene in excitatory cortical neurons prevents whisker-specific barrel formation and impairs thalamocortical afferent patterning. We used electrophysiological and voltage-sensitive dye imaging methods to assess synaptic and sensory evoked cortical activity and immunohistochemistry to examine immediate early gene expression following whisker stimulation in cortex-specific NR1 knockout (CxNR1KO) mice. In mutant mice, layer IV neurons lacked NMDAR-mediated excitatory postsynaptic currents, and temporal summation of excitatory postsynaptic potentials (EPSPs) was impaired. Barrel neurons showed both phasic and tonic responses to whisker deflection. The averaged tonic response in CxNR1KO mice was significantly less than that in control mice due to impaired EPSP temporal summation. Electrophysiological estimation of the number of thalamic neurons innervating single barrel neurons indicated a significant increase in CxNR1KO mice. Similarly, voltage-sensitive dye optical signals in response to whisker stimulation were widespread. Immediate early gene expression following whisker stimulation also showed a diffuse expression pattern in the CxNR1KO cortex compared with whisker-specific expression patterns in controls. Thus, when NMDAR function is impaired, spatial discrimination of whisker inputs is severely compromised, and sensory stimulation evokes diffuse, topographically misaligned activity in the barrel cortex.
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Affiliation(s)
- Fu-Sun Lo
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland
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Liao LD, Tsytsarev V, Delgado-Martínez I, Li ML, Erzurumlu R, Vipin A, Orellana J, Lin YR, Lai HY, Chen YY, Thakor NV. Neurovascular coupling: in vivo optical techniques for functional brain imaging. Biomed Eng Online 2013; 12:38. [PMID: 23631798 PMCID: PMC3655834 DOI: 10.1186/1475-925x-12-38] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 03/25/2013] [Indexed: 01/21/2023] Open
Abstract
Optical imaging techniques reflect different biochemical processes in the brain, which is closely related with neural activity. Scientists and clinicians employ a variety of optical imaging technologies to visualize and study the relationship between neurons, glial cells and blood vessels. In this paper, we present an overview of the current optical approaches used for the in vivo imaging of neurovascular coupling events in small animal models. These techniques include 2-photon microscopy, laser speckle contrast imaging (LSCI), voltage-sensitive dye imaging (VSDi), functional photoacoustic microscopy (fPAM), functional near-infrared spectroscopy imaging (fNIRS) and multimodal imaging techniques. The basic principles of each technique are described in detail, followed by examples of current applications from cutting-edge studies of cerebral neurovascular coupling functions and metabolic. Moreover, we provide a glimpse of the possible ways in which these techniques might be translated to human studies for clinical investigations of pathophysiology and disease. In vivo optical imaging techniques continue to expand and evolve, allowing us to discover fundamental basis of neurovascular coupling roles in cerebral physiology and pathophysiology.
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Affiliation(s)
- Lun-De Liao
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, #05-COR, Singapore 117456, Singapore
| | - Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn street, HSF-2, Baltimore, MD 21201, USA
| | - Ignacio Delgado-Martínez
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, #05-COR, Singapore 117456, Singapore
| | - Meng-Lin Li
- Department of Electrical Engineering, National Tsing Hua University, No. 101, Sec. 2, Kuang-Fu Rd, Hsinchu 300, R.O.C, Taiwan
| | - Reha Erzurumlu
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn street, HSF-2, Baltimore, MD 21201, USA
| | - Ashwati Vipin
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, #05-COR, Singapore 117456, Singapore
| | - Josue Orellana
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, #05-COR, Singapore 117456, Singapore
| | - Yan-Ren Lin
- Department of Emergency Medicine, Changhua Christian Hospital, 135 Nanshsiao Street, Changhua 500, R.O.C, Taiwan
| | - Hsin-Yi Lai
- Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital and Chang Gung University, Taoyuan 333, R.O.C, Taiwan
| | - You-Yin Chen
- Department of Biomedical Engineering, National Yang Ming University, No.155, Sec.2, Linong St, Taipei 112, R.O.C, Taiwan
| | - Nitish V Thakor
- Singapore Institute for Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, #05-COR, Singapore 117456, Singapore
- Department of Biomedical Engineering, Johns Hopkins University, Traylor 701/720 Rutland Ave, Baltimore, MD 21205, USA
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Tsytsarev V, Arakawa H, Borisov S, Pumbo E, Erzurumlu RS, Papkovsky DB. In vivo imaging of brain metabolism activity using a phosphorescent oxygen-sensitive probe. J Neurosci Methods 2013; 216:146-51. [PMID: 23624034 DOI: 10.1016/j.jneumeth.2013.04.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 04/09/2013] [Accepted: 04/11/2013] [Indexed: 12/12/2022]
Abstract
Several approaches have been adopted for real-time imaging of neural activity in vivo. We tested a new cell-penetrating phosphorescent oxygen-sensitive probe, NanO2-IR, to monitor temporal and spatial dynamics of oxygen metabolism in the neocortex following peripheral sensory stimulation. Probe solution was applied to the surface of anesthetized mouse brain; optical imaging was performed using a MiCAM-02 system. Trains of whisker stimuli were delivered and associated changes in phosphorescent signal were recorded in the contralateral somatosensory ("barrel") cortex. Sensory stimulation led to changes in oxygenation of activated areas of the barrel cortex. The oxygen imaging results were compared to those produced by the voltage-sensitive dye RH-1691. While the signals emitted by the two probes differed in shape and amplitude, they both faithfully indicated specific whisker evoked cortical activity. Thus, NanO2-IR probe can be used as a tool in visualization and real-time analysis of sensory-evoked neural activity in vivo.
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Affiliation(s)
- Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, HSF II, 20 Penn Street, Baltimore, MD 21201-1075, USA.
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Tsytsarev V, Rao B, Maslov KI, Li L, Wang LV. Photoacoustic and optical coherence tomography of epilepsy with high temporal and spatial resolution and dual optical contrasts. J Neurosci Methods 2013; 216:142-5. [PMID: 23603664 DOI: 10.1016/j.jneumeth.2013.04.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 04/01/2013] [Accepted: 04/04/2013] [Indexed: 01/26/2023]
Abstract
Epilepsy mapping with high spatial and temporal resolution has great significance for both fundamental research on epileptic neurons and the clinical management of epilepsy. In this communication, we demonstrate for the first time in vivo epilepsy mapping with high spatial and temporal resolution and dual optical contrasts in an animal model. Through the variations of a depthresolved optical coherence tomography signal with optical scattering contrast, we observed that epileptic neuron activities modulated the optical refractive index of epileptic neurons and their surrounding tissue. Simultaneously, through neurovasculature coupling mechanisms and optical absorption contrast, we used photoacoustic signals to document the hemodynamic changes of the microvasculature surrounding the epileptic neurons. The epilepsy mapping results were confirmed by a simultaneously recorded electroencephalogram signal during epileptic seizure. Our new epilepsy mapping tool, with high temporal and spatial resolution and dual optical contrasts, may find many applications, such as drug development and epilepsy surgery.
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Affiliation(s)
- Vassiliy Tsytsarev
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
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Abstract
Within the last few decades, optical imaging methods have yielded revolutionary results when applied to all parts of the central nervous system. The purpose of this review is to analyze research possibilities and limitations of several novel imaging techniques and show some of the most interesting achievements obtained by these methods. Here we covered intrinsic optical imaging, voltage-sensitive dye, photoacoustic, optical coherence tomography, near-infrared spectroscopy and some other techniques. All of them are mainly applicable for experimental neuroscience but some of them also suitable for the clinical studies.
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Affiliation(s)
- Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, HSF II Room S251, 20 Penn Street, Baltimore, MD 21201-1075, USA
| | - Chad Bernardelli
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, HSF II Room S251, 20 Penn Street, Baltimore, MD 21201-1075, USA
| | - Konstantin I Maslov
- Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130, USA
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Lenkov DN, Volnova AB, Pope ARD, Tsytsarev V. Advantages and limitations of brain imaging methods in the research of absence epilepsy in humans and animal models. J Neurosci Methods 2012; 212:195-202. [PMID: 23137652 DOI: 10.1016/j.jneumeth.2012.10.018] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 10/24/2012] [Accepted: 10/25/2012] [Indexed: 12/18/2022]
Abstract
The purpose of this review is to analyze research possibilities and limitations of several methods, technical tools and their combinations for elucidation of absence epilepsy mechanisms, particularly the childhood absences. Despite the notable collection of simultaneous recording of clinical electroencephalography (EEG) and behavioral changes in relation to absence seizures, shortcomings of scalp EEG in both spatial resolution and precise detection of subcortical centers have limited the understanding of the fundamental mechanisms of altered brain function during and after recurrent epileptic paroxysms. Therefore, in the past decade, EEG recordings have often been combined with simultaneous imaging methods in epilepsy studies. Among imaging methods, the following ones are used regularly: functional magnetic resonance imaging (fMRI), positron-emission tomography (PET), low-resolution electromagnetic tomography (LORETA), single photon emission spectroscopy (SPECT), near-infrared spectroscopy (NIRS), and optical imaging of intrinsic signals (IOS). In addition, voltage-sensitive dye optical imaging method and even photoacoustic microscopy can be applied to animal models of epilepsy. Samplings of some of the most relevant data obtained by the above methods are presented. It appears that the elaboration of more adequate animal models of the patterns of absence seizures during the early postnatal period is necessary for better correspondence of human and animal absence phenomena.
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Affiliation(s)
- Dmitry N Lenkov
- Nevsky Center of Scientific Collaboration-Saint Petersburg, Razjezshaya 43/1 Liter A, Suite 8N, Saint Petersburg 192119, Russia
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Yao J, Xia J, Maslov KI, Nasiriavanaki M, Tsytsarev V, Demchenko AV, Wang LV. Noninvasive photoacoustic computed tomography of mouse brain metabolism in vivo. Neuroimage 2012; 64:257-66. [PMID: 22940116 DOI: 10.1016/j.neuroimage.2012.08.054] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 08/13/2012] [Accepted: 08/15/2012] [Indexed: 10/28/2022] Open
Abstract
We have demonstrated the feasibility of imaging mouse brain metabolism using photoacoustic computed tomography (PACT), a fast, noninvasive and functional imaging modality with optical contrast and acoustic resolution. Brain responses to forepaw stimulations were imaged transdermally and transcranially. 2-NBDG, which diffuses well across the blood-brain-barrier, provided exogenous contrast for photoacoustic imaging of glucose response. Concurrently, hemoglobin provided endogenous contrast for photoacoustic imaging of hemodynamic response. Glucose and hemodynamic responses were quantitatively decoupled by using two-wavelength measurements. We found that glucose uptake and blood perfusion around the somatosensory region of the contralateral hemisphere were both increased by stimulations, indicating elevated neuron activity. While the glucose response area was more homogenous and confined within the somatosensory region, the hemodynamic response area had a clear vascular pattern and spread wider than the somatosensory region. Our results demonstrate that 2-NBDG-enhanced PACT is a promising tool for noninvasive studies of brain metabolism.
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Affiliation(s)
- Junjie Yao
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
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Tsytsarev V, Maslov KI, Yao J, Parameswar AR, Demchenko AV, Wang LV. In vivo imaging of epileptic activity using 2-NBDG, a fluorescent deoxyglucose analog. J Neurosci Methods 2011; 203:136-40. [PMID: 21939688 DOI: 10.1016/j.jneumeth.2011.09.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 09/06/2011] [Accepted: 09/07/2011] [Indexed: 11/15/2022]
Abstract
Accurately locating epileptic foci has great importance in advancing the treatment of epilepsy. In this study, epileptic seizures were first induced by intracortical injection of 4-aminopyridine in rats. A fluorescent deoxyglucose substitute, 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (2-NBDG), was then continuously injected via the tail vein. Brain glucose metabolism was subsequently monitored by fluorescence imaging of 2-NBDG. The initial uptake rate of 2-NBDG at the injection site of 4-aminopyridine significantly exceeded that of the control injection site, which indicated local hypermetabolism induced by seizures. Our results show that 2-NBDG can be used for localizing epileptic foci.
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Affiliation(s)
- Vassiliy Tsytsarev
- Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA.
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Tsytsarev V, Hu S, Yao J, Maslov K, Barbour DL, Wang LV. Photoacoustic microscopy of microvascular responses to cortical electrical stimulation. J Biomed Opt 2011; 16:076002. [PMID: 21806263 PMCID: PMC3144972 DOI: 10.1117/1.3594785] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Revised: 04/04/2011] [Accepted: 05/05/2011] [Indexed: 05/18/2023]
Abstract
Advances in the functional imaging of cortical hemodynamics have greatly facilitated the understanding of neurovascular coupling. In this study, label-free optical-resolution photoacoustic microscopy (OR-PAM) was used to monitor microvascular responses to direct electrical stimulations of the mouse somatosensory cortex through a cranial opening. The responses appeared in two forms: vasoconstriction and vasodilatation. The transition between these two forms of response was observed in single vessels by varying the stimulation intensity. Marked correlation was found between the current-dependent responses of two daughter vessels bifurcating from the same parent vessel. Statistical analysis of twenty-seven vessels from three different animals further characterized the spatial-temporal features and the current dependence of the microvascular response. Our results demonstrate that OR-PAM is a valuable tool to study neurovascular coupling at the microscopic level.
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Affiliation(s)
- Vassiliy Tsytsarev
- Washington University in St. Louis, Department of Biomedical Engineering, One Brookings Drive, St. Louis, Missouri 63130, USA
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Tsytsarev V, Pope D, Pumbo E, Yablonskii A, Hofmann M. Study of the cortical representation of whisker directional deflection using voltage-sensitive dye optical imaging. Neuroimage 2010; 53:233-8. [PMID: 20558304 DOI: 10.1016/j.neuroimage.2010.06.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 06/04/2010] [Accepted: 06/08/2010] [Indexed: 10/19/2022] Open
Abstract
Using voltage-sensitive dye optical imaging methods, we visualized neural activity in the rat barrel cortex in response to the deflection of a single whisker in different directions. Obtained data indicates that fast movements of single whiskers in varying directions correlate with different patterns of activation in the somatosensory cortex. A functional map was created based on the voltage-sensitive dye optical signal. This supports prior research that vibrissae deflections cause responses in different cortical neurons within the barrel field according to the direction of the deflection. By analogy with the orientation columns in the visual cortex, directionally biased single-whisker responses to different directions of deflection could be a possible mechanism for the directional selectivity of this important sensory response.
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Affiliation(s)
- Vassiliy Tsytsarev
- Department of Biomedical Engineering, Washington University in St. Louis, Box 1097, One Brookings Drive, St. Louis, MO 63130, USA.
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Tsytsarev V, Pope D, Pumbo E, Garver W. Intrinsic optical imaging of directional selectivity in rat barrel cortex: Application of a multidirectional magnetic whisker stimulator. J Neurosci Methods 2010; 189:80-3. [DOI: 10.1016/j.jneumeth.2010.03.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 03/04/2010] [Accepted: 03/11/2010] [Indexed: 10/19/2022]
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Abstract
Optical-resolution photoacoustic microscopy (OR-PAM) is applied to functional brain imaging in living mice. A near-diffraction-limited bright-field optical illumination is employed to achieve micrometer lateral resolution, and a dual-wavelength measurement is utilized to extract the blood oxygenation information. The variation in hemoglobin oxygen saturation (sO(2)) along vascular branching has been imaged in a precapillary arteriolar tree and a postcapillary venular tree, respectively. To the best of our knowledge, this is the first report on in vivo volumetric imaging of brain microvascular morphology and oxygenation down to single capillaries through intact mouse skulls. It is anticipated that: (i) chronic imaging enabled by this minimally invasive procedure will advance the study of cortical plasticity and neurological diseases; (ii) revealing the neuroactivity-dependent changes in hemoglobin concentration and oxygenation will facilitate the understanding of neurovascular coupling at the capillary level; and (iii) combining functional OR-PAM and high-resolution blood flowmetry will have the potential to explore cellular pathways of brain energy metabolism.
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Tsytsarev V, Fukuyama H, Pope D, Pumbo E, Kimura M. Optical imaging of interaural time difference representation in rat auditory cortex. Front Neuroeng 2009; 2:2. [PMID: 19277218 PMCID: PMC2654020 DOI: 10.3389/neuro.16.002.2009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Accepted: 01/31/2009] [Indexed: 11/30/2022]
Abstract
We used in vivo voltage-sensitive dye optical imaging to examine the cortical representation of interaural time difference (ITD), which is believed to be involved in sound source localization. We found that acoustic stimuli with dissimilar ITD activate various localized domains in the auditory cortex. The main loci of the activation pattern shift up to 1 mm during the first 40 ms of the response period. We suppose that some of the neurons in each pool are sensitive to the definite ITD and involved in the transduction of information about sound source localization, based on the ITD. This assumption gives a reasonable fit to the Jeffress model in which the neural network calculates the ITD to define the direction of the sound source. Such calculation forms the basis for the cortex's ability to detect the azimuth of the sound source.
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Affiliation(s)
- Vassiliy Tsytsarev
- Washington University, Department of Biomedical Engineering St Louis, MO, USA
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Tsytsarev V, Premachandra K, Takeshita D, Bahar S. Imaging cortical electrical stimulation in vivo: fast intrinsic optical signal versus voltage-sensitive dyes. Opt Lett 2008; 33:1032-4. [PMID: 18451977 DOI: 10.1364/ol.33.001032] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We applied high-temporal-resolution optical imaging utilizing both the fast intrinsic optical signal (fIOS) and voltage-sensitive dyes (VSDs) to observe the spatiotemporal characteristics of rat somatosensory cortex during electrical stimulation. We find that changes in both the fIOS and VSD signals occur rapidly (<30 ms) after the stimulus is applied, suggesting that both membrane depolarization and transmembrane ion movement occur shortly after the stimulus, preceding the more gradual physiological changes in oxygen consumption revealed by the slower component of the intrinsic optical signal. We find that the VSD signal spreads through a much larger area of cortex than the fIOS.
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Affiliation(s)
- Vassiliy Tsytsarev
- Department of Physics and Astronomy and Center for Neurodynamics, University of Missouri at St. Louis, One University Boulevard, St. Louis, Missouri 63121, USA.
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Abstract
In the study of the spatiotemporal properties of the cortex, a demand often arises for recording local field evoked potentials (LFEP) and neural spikes from a quantity of points at close range from each other. In such a situation a device composed of a lot of electrodes assembled in a single bunch would be suitable. Such circumstances gave us the impetus to create the device described in this paper, namely a new planar electrode array for in vivo multisite extracellular recording. The device is made of plastic and includes platinum electrodes 50 microm in diameter. The array of 64 incorporated microelectrodes is placed on the surface of the cortex of anesthetized rats. Recordings could be made through all electrodes for more than 1 h without damage to the cortex. The inter-polar distance is approximately 100 microm so that each individual electrode can record activity from a separate population of neurons near the cortical surface. The recording system described here is highly useful for visualizing spatiotemporal structure of the cortical activities and for imaging dynamic neuronal assemblies.
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Affiliation(s)
- Vassiliy Tsytsarev
- Laboratory for Visual Neurocomputing, Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
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Callan DE, Tsytsarev V, Hanakawa T, Callan AM, Katsuhara M, Fukuyama H, Turner R. Song and speech: Brain regions involved with perception and covert production. Neuroimage 2006; 31:1327-42. [PMID: 16546406 DOI: 10.1016/j.neuroimage.2006.01.036] [Citation(s) in RCA: 158] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2005] [Revised: 01/12/2006] [Accepted: 01/16/2006] [Indexed: 10/24/2022] Open
Abstract
This 3-T fMRI study investigates brain regions similarly and differentially involved with listening and covert production of singing relative to speech. Given the greater use of auditory-motor self-monitoring and imagery with respect to consonance in singing, brain regions involved with these processes are predicted to be differentially active for singing more than for speech. The stimuli consisted of six Japanese songs. A block design was employed in which the tasks for the subject were to listen passively to singing of the song lyrics, passively listen to speaking of the song lyrics, covertly sing the song lyrics visually presented, covertly speak the song lyrics visually presented, and to rest. The conjunction of passive listening and covert production tasks used in this study allow for general neural processes underlying both perception and production to be discerned that are not exclusively a result of stimulus induced auditory processing nor to low level articulatory motor control. Brain regions involved with both perception and production for singing as well as speech were found to include the left planum temporale/superior temporal parietal region, as well as left and right premotor cortex, lateral aspect of the VI lobule of posterior cerebellum, anterior superior temporal gyrus, and planum polare. Greater activity for the singing over the speech condition for both the listening and covert production tasks was found in the right planum temporale. Greater activity in brain regions involved with consonance, orbitofrontal cortex (listening task), subcallosal cingulate (covert production task) were also present for singing over speech. The results are consistent with the PT mediating representational transformation across auditory and motor domains in response to consonance for singing over that of speech. Hemispheric laterality was assessed by paired t tests between active voxels in the contrast of interest relative to the left-right flipped contrast of interest calculated from images normalized to the left-right reflected template. Consistent with some hypotheses regarding hemispheric specialization, a pattern of differential laterality for speech over singing (both covert production and listening tasks) occurs in the left temporal lobe, whereas, singing over speech (listening task only) occurs in right temporal lobe.
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Affiliation(s)
- Daniel E Callan
- ATR Computational Neuroscience Laboratories, Soraku-gun, Kyoto 619-0288, Japan.
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Tsytsarev V, Yamazaki T, Ribot J, Tanaka S. Sound frequency representation in cat auditory cortex. Neuroimage 2005; 23:1246-55. [PMID: 15589090 DOI: 10.1016/j.neuroimage.2004.08.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2003] [Revised: 05/24/2004] [Accepted: 08/18/2004] [Indexed: 11/28/2022] Open
Abstract
Using the intrinsic signal optical recording technique, we reconstructed the two-dimensional pattern of stimulus-evoked neuronal activities in the auditory cortex of anesthetized and paralyzed cats. The average magnitude of intrinsic signal in response to a pure tone stimulus increased steadily as the sound pressure level increased. A detailed analysis demonstrated that the evoked signals at early frames were scaled by the sound pressure level, which in turn indicated the presence of a minimum level of sound pressure beyond which stimulus-related intrinsic signal can be generated. Intrinsic signals evoked significantly by pure tone stimuli of different frequencies were localized and arranged in an orderly manner in the middle ectosylvian gyrus, which indicates that the primary auditory field (AI) is tonotopically organized. The arrangement of optimal frequencies obtained from optical recordings of the same auditory cortex, which were conducted on different days, was highly reproducible. Furthermore, other auditory fields surrounding AI in the recorded area were allocated based on the observed tonotopicity. We also conducted unit recordings on the cats used for optical recording with the same set of acoustic stimuli. The gross feature of the arrangement of optimal frequencies determined by unit recordings agreed with the tonotopic arrangement determined by the optical recording, although the precise agreement was not obtained.
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Affiliation(s)
- Vassiliy Tsytsarev
- Laboratory for Visual Neurocomputing, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
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Tsytsarev V, Tanaka S. Intrinsic optical signals from rat primary auditory cortex in response to sound stimuli presented to contralateral, ipsilateral and bilateral ears. Neuroreport 2002; 13:1661-6. [PMID: 12352623 DOI: 10.1097/00001756-200209160-00019] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In the auditory cortex, primitive features of acoustic stimuli are represented for auditory scene analysis. A typical example of a feature representation is the tonotopic map, in which sound frequencies are spatially arranged in an orderly manner. Some neurons in the auditory cortex are sensitive to sound source location, which is another important feature for auditory scene analysis. In the present study, using the intrinsic optical imaging technique, we attempted to visualize the two-dimensional pattern of neuronal population responses in the primary auditory cortex of rats to pure tones presented at various frequencies and sound intensities. The observed arrangements of sound frequencies were consistent with those obtained by electrophysiological mapping, which indicates that our intrinsic optical recording can visualize populational responses of neurons. We also found different temporal patterns of intrinsic signals elicited in response to contralateral, ipsilateral, and bilateral ear stimulations. Finally we try to explain the observed differential time courses of intrinsic signal responses from the theoretical point of view on the conduction of neural activities, based on the so far anatomically identified neural pathways in the rodent auditory system.
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Affiliation(s)
- Vassiliy Tsytsarev
- Laboratory for Visual Neurocomputing, Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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