Publications by authors named "Kerstin Lenk"

Recent studies indicate that astrocytes show heterogeneity in morphology and physiological function. They integrate synaptic signals and release calcium in reaction to active neurons. These calcium signals are not yet fully understood as they are highly dependent on the cell's morphology, which can vary across and within brain regions.

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Article Synopsis
  • The study investigates how astrocytes influence electrical activity during the formation of neuronal networks using advanced signal analysis techniques.
  • The researchers performed experiments with rat cortical neurons and astrocytes on microelectrode arrays, varying the ratios of the two cell types.
  • Findings indicate that astrocytes cause a desynchronization of neural activity and alter the actions potentials, emphasizing the need for comprehensive analysis when examining astrocytic control and potential neuronal dysfunction.
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The non-selective cation channel TRPC1 is highly expressed in the brain. Recent research shows that neuronal TRPC1 forms heteromeric complexes with TRPC4 and TRPC5, with a small portion existing as homotetramers, primarily in the ER. Given that most studies have focused on the role of heteromeric TRPC1/4/5 complexes, it is crucial to investigate the specific role of homomeric TRPC1 in maintaining brain homeostasis.

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Astrocytes are the largest subset of glial cells and perform structural, metabolic, and regulatory functions. They are directly involved in the communication at neuronal synapses and the maintenance of brain homeostasis. Several disorders, such as Alzheimer's, epilepsy, and schizophrenia, have been associated with astrocyte dysfunction.

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Astrocytes and neurons respond to each other by releasing transmitters, such as γ-aminobutyric acid (GABA) and glutamate, that modulate the synaptic transmission and electrochemical behavior of both cell types. Astrocytes also maintain neuronal homeostasis by clearing neurotransmitters from the extracellular space. These astrocytic actions are altered in diseases involving malfunction of neurons, e.

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According to the tripartite synapse model, astrocytes have a modulatory effect on neuronal signal transmission. More recently, astrocyte malfunction has been associated with psychiatric diseases such as schizophrenia. Several hypotheses have been proposed on the pathological mechanisms of astrocytes in schizophrenia.

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Cortical spreading depression (CSD) is a slowly propagating wave of depolarization of brain cells, followed by temporary silenced electrical brain activity. Major structural changes during CSD are linked to neuronal and possibly glial swelling. However, basic questions still remain unanswered.

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Recent research in neuroscience indicates the importance of tripartite synapses and gliotransmission mediated by astrocytes in neuronal system modulation. Although the astrocyte and neuronal network functions are interrelated, they are fundamentally different in their signaling patterns and, possibly, the time scales at which they operate. However, the exact nature of gliotransmission and the effect of the tripartite synapse function at the network level are currently elusive.

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Human astrocytes differ dramatically in cell morphology and gene expression from murine astrocytes. The latter are well known to be of major importance in the formation of neuronal networks by promoting synapse maturation. However, whether human astrocyte lineage cells have a similar role in network formation has not been firmly established.

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Article Synopsis
  • - Researchers focused on miR-124, a non-coding RNA, to understand its role in neuronal differentiation and its complex regulation of various biological processes during neurogenesis.
  • - They utilized CRISPR/Cas9 technology to delete all six miR-124 alleles in human stem cells, leading to the formation of functional neurons with changed structure and neurotransmitter types.
  • - By identifying 98 key targets of miR-124 and analyzing their effects on cell viability and neuronal characteristics, the study highlighted the importance of combining experimental and systemic approaches to fully understand miRNA roles in human brain neurogenesis.
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Neuronal networks are often characterized by their spiking and bursting statistics. Previously, we introduced an adaptive burst analysis method which enhances the analysis power for neuronal networks with highly varying firing dynamics. The adaptation is based on single channels analyzing each element of a network separately.

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Background: Measures of spike train synchrony are widely used in both experimental and computational neuroscience. Time-scale independent and parameter-free measures, such as the ISI-distance, the SPIKE-distance and SPIKE-synchronization, are preferable to time scale parametric measures, since by adapting to the local firing rate they take into account all the time scales of a given dataset.

New Method: In data containing multiple time scales (e.

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Astrocytes actively influence the behavior of the surrounding neuronal network including changes of the synaptic plasticity and neuronal excitability. These dynamics are altered in diseases like Alzheimer's, where the release of the gliotransmitter GABA is increased by affected, so called reactive astrocytes. In this paper, we aim to simulate a neural network with altered astrocytic GABA release.

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The idea that astrocytes may be active partners in synaptic information processing has recently emerged from abundant experimental reports. Because of their spatial proximity to neurons and their bidirectional communication with them, astrocytes are now considered as an important third element of the synapse. Astrocytes integrate and process synaptic information and by doing so generate cytosolic calcium signals that are believed to reflect neuronal transmitter release.

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Synchrony and asynchrony are essential aspects of the functioning of interconnected neuronal cells and networks. New information on neuronal synchronization can be expected to aid in understanding these systems. Synchronization provides insight in the functional connectivity and the spatial distribution of the information processing in the networks.

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Background: Microelectrode array (MEA) is a widely used technique to study for example the functional properties of neuronal networks derived from human embryonic stem cells (hESC-NN). With hESC-NN, we can investigate the earliest developmental stages of neuronal network formation in the human brain.

Methods: In this paper, we propose an in silico model of maturating hESC-NNs based on a phenomenological model called INEX.

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