Article
Cell Biology
Vanessa Jorge Henriques, Angela Chiavegato, Giorgio Carmignoto, Marta Gomez-Gonzalo
Summary: In this study, optogenetics and 2-photon Ca2+ imaging experiments were used to investigate the signaling between Somatostatin (SST)-releasing GABAergic interneurons and astrocytes in brain slice preparations from the visual cortex. It was found that intense stimulation of SST interneurons evokes Ca2+ elevations in astrocytes depending on GABA(B) receptor activation, with this response modulated by the neuropeptide somatostatin. Additionally, after episodes of SST interneuron hyperactivity, a long-lasting reduction of inhibitory postsynaptic current (IPSC) onto pyramidal neurons was observed, which was counterbalanced by the activation of astrocytes that upregulate SST interneuron-evoked IPSC amplitude through the release of ATP and conversion to adenosine.
Article
Clinical Neurology
Carmen Nanclares, Jonah Poynter, Hector A. Martell-Martinez, Scott Vermilyea, Alfonso Araque, Paulo Kofuji, Michael K. Lee, Ana Covelo
Summary: alpha-Synuclein, a major component of Lewy bodies and Lewy neurites, is closely related to Parkinson's disease and other alpha-synucleinopathies. This study demonstrates that the expression of mutant A53T alpha-synuclein alters the intrinsic properties of astrocytes, leading to Ca2+ hyperexcitability and enhanced gliotransmission, which may contribute to the neuronal and synaptic dysfunction observed in alpha-synucleinopathies.
ACTA NEUROPATHOLOGICA
(2023)
Article
Multidisciplinary Sciences
Maurizio De Pitta, Nicolas Brunel
Summary: Persistent activity, time-varying activity, and activity-silent mechanisms in populations of neurons have been proposed as different mechanisms of working memory. This study investigates a network model that includes both neurons and astrocytes and shows that glia-synapse interactions can lead to multiple stable states of synaptic transmission, which can serve as substrates for working memory.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Neurosciences
Abel Eraso-Pichot, Sandrine Pouvreau, Alexandre Olivera-Pinto, Paula Gomez-Sotres, Urszula Skupio, Giovanni Marsicano
Summary: The study of astrocytic contribution to brain functions has gained popularity in neuroscience. Recent discoveries have shown the involvement of astrocytes in synaptic functions and revealed their previously unimaginable multiple functions. Additionally, research on cannabinoids has identified different ways they interact with astrocytes, modify their functions, alter their communication with neurons, and impact behavior. This review discusses the expression of endocannabinoid system members in astrocytes and the latest findings on cannabinoid modulation of important astroglial functions, such as calcium dynamics, gliotransmission, metabolism, and inflammation.
Review
Neurosciences
Julianna Goenaga, Alfonso Araque, Paulo Kofuji, Daniela Herrera Moro Chao
Summary: Glia are supportive cells in the brain that have traditionally been thought to play passive roles. However, recent evidence shows that a specific type of glia called astrocytes can actively influence neural information processing. Astrocytes can sense synaptic activity and release gliotransmitters which modulate neuronal activity and synaptic transmission, impacting animal behavior. This interaction between astrocytes and neurons is known as the tripartite synapse, where astrocytes are integral to synaptic function. In this review, the authors discuss how calcium-mediated excitability in astrocytes modulates synaptic information processing at different scales.
FRONTIERS IN SYNAPTIC NEUROSCIENCE
(2023)
Review
Biochemistry & Molecular Biology
Steven A. Hill, Marissa Fu, A. Denise R. Garcia
Summary: Astrocytes are complex cells performing essential functions in the nervous system. The Sonic hedgehog (Shh) signaling pathway plays a crucial role in regulating the molecular identity and functional properties of astrocytes, and is active in specific subpopulations of these cells throughout the brain.
CELLULAR AND MOLECULAR LIFE SCIENCES
(2021)
Article
Computer Science, Interdisciplinary Applications
Tiina Manninen, Jugoslava Acimovic, Marja-Leena Linne
Summary: Neural networks are widely used in modeling brain systems to explore global dynamics and emergent properties, and recent research has focused on neuron-astrocyte interactions and astrocytic modulation of neural dynamics. Various computational models incorporating these interactions have been developed to study synchronization, information transfer, synaptic plasticity, and other aspects. This study analyzes the evolution of network models with at least two neurons and astrocytes, and proposes a systematic framework for describing and categorizing cell-cell interaction schemes in neuron-astrocyte networks. The study also highlights the need for more comprehensive data and computational tools to further understand the contribution of astrocytes to brain functions.
Article
Biotechnology & Applied Microbiology
Won-Seok Lee, Ji-Hye Kang, Jung-Hwan Lee, Yoo Sung Kim, Jongmin Joseph Kim, Han-Sem Kim, Hae-Won Kim, Ueon Sang Shin, Bo-Eun Yoon
Summary: The study utilized carbon nanotube platforms to enhance astrocyte functions, such as improving cell adhesion, proliferation, and gliotransmission, by increasing resting Ca2+ levels.
JOURNAL OF NANOBIOTECHNOLOGY
(2022)
Review
Biochemistry & Molecular Biology
Nikita Arnst, Nelly Redolfi, Annamaria Lia, Martina Bedetta, Elisa Greotti, Paola Pizzo
Summary: Alzheimer's disease is a neurodegenerative illness characterized by the loss of neurons in specific brain areas. The calcium hypothesis is at the forefront of current research as a potential key pathway in Alzheimer's disease.
Article
Cell Biology
Beatrice Vignoli, Marco Canossa
Summary: This study assessed the contribution of BDNF to synaptic strengthening by deleting TrkB in cortical astrocytes. The results showed that TrkB signaling in astrocytes is not essential for transducing BDNF activity for synaptic potentiation.
Article
Neurosciences
Carmen Nanclares, Jose Antonio Noriega-Prieto, Francisco E. Labrada-Moncada, Marija Cvetanovic, Alfonso Araque, Paulo Kofuji
Summary: Spinocerebellar ataxia type 1 (SCA1) is a neurodegenerative disease characterized by progressive cerebellar ataxia. This study found that the intrinsic electrical properties of Purkinje cells (PCs) in SCA1 mice were altered, and these alterations were associated with the hyperexcitability of Bergmann glia (BG). Preventing BG hyperexcitability in SCA1 mice restored the normal function of PCs.
NEUROBIOLOGY OF DISEASE
(2023)
Review
Neurosciences
Paulo Kofuji, Alfonso Araque
Summary: Astrocytes play key supportive roles in brain function, with the ability to sense and respond to synaptic activity through a wide variety of neurotransmitter transporters and receptors. Activation of astrocytes by synaptically released neurotransmitters leads to the release of gliotransmitters, influencing synaptic regulation.
Article
Neurosciences
Egor Dzyubenko, Wojciech Prazuch, Matthias Pillath-Eilers, Joanna Polanska, Dirk M. Hermann
Summary: The Astral software package is a novel tool for analyzing intercellular communication in astrocytic networks, without the need for assigning regions of interest. By using this tool, the network-wide quantification of Ca++ events and the analysis of their intercellular propagation can be achieved.
FRONTIERS IN CELLULAR NEUROSCIENCE
(2021)
Article
Neurosciences
Andres M. Baraibar, Lindsey Belisle, Giovanni Marsicano, Carlos Matute, Susana Mato, Alfonso Araque, Paulo Kofuji
Summary: Microcircuits in the neocortex are functionally organized along layers and columns, and astrocytes play a role in the functional organization and bidirectional interaction between neurons. Activation of astrocytes by endocannabinoids leads to an increase in Ca2+ levels, ATP/adenosine release, and temporary synaptic depression between layer 5 pyramidal neurons at relatively distant synapses. This form of heteroneuronal synaptic depression is specific to cortical columns and layers, depending on layer-specific neuron-to-astrocyte signaling.
Review
Biochemistry & Molecular Biology
Jiao Yao, Cong Chen, Yi Guo, Yantao Yang, Xinya Liu, Shifeng Chu, Qidi Ai, Zhao Zhang, Meiyu Lin, Songwei Yang, Naihong Chen
Summary: Depression has a negative impact on physical and mental health, and the exact pathophysiology is still unknown. The focus of research has shifted to the interactions between astrocytes, neurons, and depression. This review summarizes the pathological changes of neurons and astrocytes, and their interactions in depression.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Endocrinology & Metabolism
Shinya Abe, Reijo Kouhia, Riku Nikander, Nathaniel Narra, Jari Hyttinen, Harri Sievanen
Summary: This study compared the fracture loads during falls of different sports athletes and controls, and found that high impact and repetitive impact athletes had higher fracture loads in all fall directions, while odd-impact athletes had higher fracture loads in specific fall directions.
Article
Biophysics
Sanna Halonen, Ali Ovissi, Sonja Boyd, Juho Kari, Kai Kronstrom, Juhani Kosunen, Hanna Lauren, Kirsti Numminen, Harri Sievanen, Jari Hyttinen
Summary: This study evaluated the clinical feasibility of a novel bioimpedance biopsy needle system in liver biopsy and collected in vivo bioimpedance data from human liver and tumor tissues. The results showed significant differences in median bioimpedance values between liver and tumor tissue at certain frequency ranges. This study provides preliminary evidence that tumor tissue differs from liver tissue in vivo and this difference is frequency-dependent.
PHYSIOLOGICAL MEASUREMENT
(2022)
Article
Engineering, Biomedical
Antti Paldanius, Bachir Dekdouk, Jussi Toivanen, Ville Kolehmainen, Jari Hyttinen
Summary: This study investigates the importance of accurate head modeling and the impact of head inhomogeneities on electrical impedance tomography (EIT) measurements. The results highlight the significant influence of accurate tissue geometry and conductivity on EIT measurements, particularly the conductivity of cerebrospinal fluid. The study emphasizes the need to consider detailed cerebrospinal fluid geometry in EIT calculations.
IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING
(2022)
Article
Biochemical Research Methods
Lisa Blum Moyse, Hugues Berry
Summary: Up-Down synchronization in neuronal networks can be modulated by gliotransmission events from astrocytes, as demonstrated in our three-population neural network model.
PLOS COMPUTATIONAL BIOLOGY
(2022)
Article
Neurosciences
Audrey Denizot, Misa Arizono, U. Valentin Nagerl, Hugues Berry, Erik De Schutter
Summary: This study investigates the relationship between astrocytic nanoscale morphology and Ca2+ activity using computational tools and idealized 3D geometries. The results demonstrate that astrocytic morphology significantly influences Ca2+ signals, with swelling hindering signal propagation. This highlights the importance of astrocyte morphology in neuron-astrocyte communication, particularly in pathological conditions.
Article
Biochemistry & Molecular Biology
Michael Taynnan Barros, Harun Siljak, Peter Mullen, Constantinos Papadias, Jari Hyttinen, Nicola Marchetti
Summary: This paper proposes a novel objective classification model of biological neuronal morphology and electrical types and their networks based on the attributes of neuronal communication. Experimental results show that the proposed method achieves an accuracy of up to 70% for classification and up to 65% for inferring biological network structures using network tomography. Support Vector Machine (SVM) methods perform better among the used techniques.
Article
Immunology
Johannes Virta, Markus Hannula, Katri Lindfors, Ilmari Tamminen, Juha Taavela, Heini Huhtala, Katri Kaukinen, Paeivi Saavalainen, Jari Hyttinen, Kalle Kurppa
Summary: This study validated the use of micro-CT imaging method for accurate evaluation of duodenal histomorphometry and mucosal surface areas. The method showed excellent accuracy and reproducibility, making it a powerful tool for diagnosing celiac disease and conducting clinical and pharmacological studies.
FRONTIERS IN IMMUNOLOGY
(2022)
Article
Multidisciplinary Sciences
Yulia Dembitskaya, Charlotte Piette, Sylvie Perez, Hugues Berry, Pierre J. Magistretti, Laurent Venance
Summary: The study shows that glucose and lactate play different roles in memory engram and neural computation. Lactate is important for high-stimulation load activity patterns and high attentional load in cognitive tasks, while glucose is sufficient for less demanding neural computation and learning tasks.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Cell Biology
Elina Mantyla, Toni Montonen, Lucio Azzari, Salla Mattola, Markus Hannula, Maija Vihinen-Ranta, Jari Hyttinen, Minnamari Vippola, Alessandro Foi, Soile Nymark, Teemu O. Ihalainen
Summary: Investigation of nuclear lamina architecture relies on superresolved microscopy. We developed an iterative indirect immunofluorescence staining approach combined with expansion microscopy (ExM) and structured illumination microscopy to improve superresolution microscopy of sub-nuclear nanostructures like lamins. Our method provides technical improvements to ExM including three-dimensional-printed gel casting equipment, and shows potential in quantitative superresolution ExM imaging of nuclear lamina and revealing nanoscopic details of the lamin network organization.
MOLECULAR BIOLOGY OF THE CELL
(2023)
Article
Cell & Tissue Engineering
Aapo Tervonen, Sanna Korpela, Soile Nymark, Jari Hyttinen, Teemu O. Ihalainen
Summary: The influence of mechanical forces and microenvironment on cellular behavior has been recognized. This study utilized experimental and computational methods to investigate the effects of substrate stiffness and heterogeneities on force transduction and cellular deformation. It was found that substrate stiffness and gradients can impact strain redistribution in cell monolayers, and the cells' apico-basal elasticity can provide mechanical isolation between cell-cell junctions and focal adhesions.
CELLULAR AND MOLECULAR BIOENGINEERING
(2023)
Article
Engineering, Biomedical
Birhanu Belay, Elina Mantyla, Christian Maibohm, Oscar F. Silvestre, Jari Hyttinen, Jana B. Nieder, Teemu O. Ihalainen
Summary: Cellular physiology has traditionally been studied using two-dimensional cell culture substrates, which do not accurately mimic the in vivo extracellular environment and interactions. This has led to a demand for more complex model systems in life sciences. Micro-engineered scaffolds have shown promise in understanding the role of physical cues in regulating cellular functions. In this study, we used direct laser writing via two-photon polymerization to create substrates with different surface microtopographies, and combined this with advanced high-resolution spectral imaging to investigate the effects on cellular alignment, nuclear morphology, and mechanics. We found that certain microtopographies influenced cell behavior, such as actin organization and nuclear force transduction.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2023)
Article
Cell & Tissue Engineering
Reetta Sartoneva, Kaarlo Paakinaho, Markus Hannula, Kirsi Kuismanen, Heini Huhtala, Jari Hyttinen, Susanna Miettinen
Summary: This study evaluated the effect of A2P on vaginal tissue engineering for the first time and the results are highly encouraging. The scPLCL(A2P) scaffold showed potential as a scaffold for vaginal tissue engineering, promoting the viability, proliferation, and collagen production of vaginal cells.
TISSUE ENGINEERING AND REGENERATIVE MEDICINE
(2023)
Article
Oncology
Rachel Kerslake, Birhanu Belay, Suzana Panfilov, Marcia Hall, Ioannis Kyrou, Harpal S. S. Randeva, Jari Hyttinen, Emmanouil Karteris, Cristina Sisu
Summary: This study evaluates the impact of growth conditions on cancer cells and compares their behavior to traditional two-dimensional models using transcriptomics, clinical, and novel experimental data. The results show that variability in growth conditions can affect key cancer genes and biological processes. It highlights the need for future studies to identify the most suitable in vitro/preclinical model for studying tumor microenvironments.
Article
Cell & Tissue Engineering
Alma Kurki, Kaarlo Paakinaho, Markus Hannula, Jari Hyttinen, Susanna Miettinen, Reetta Sartoneva
Summary: Tissue engineering offers a new approach for reconstructing large urethral defects, which currently lack optimal repair methods. Cell-seeded scaffolds, including the novel scPLCL(A2P) scaffold, show promise in preventing urethral stricture and promoting urothelial and stromal tissue regeneration. The scPLCL(A2P) scaffold supports the growth and phenotype maintenance of human urothelial cells (hUC) and human adipose-derived stromal cells (hASC) in both mono- and coculture environments.
JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE
(2023)
Article
Materials Science, Multidisciplinary
Inari Lyyra, Nina Sandberg, Vijay Singh Parihar, Markus Hannula, Heini Huhtala, Jari Hyttinen, Jonathan Massera, Minna Kellomaki
Summary: Polylactides (PLAs) have been extensively studied for biomedical engineering applications, but their rigidity limits their use. Blending them with more flexible polymers, such as polybutylene succinate (PBSu), results in softer materials and expands their potential applications. Bioactivity is a limitation of biopolymers, which can be improved by adding bioactive glass. Blending and compounding PLA/PBSu blends with bioactive glass enables the production of materials with a wide range of mechanical properties, suitable for tissue engineering applications.
MATERIALS TODAY COMMUNICATIONS
(2023)