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Meiser S, Sleeboom JM, Arkhypchuk I, Sandbote K, Kretzberg J. Cell anatomy and network input explain differences within but not between leech touch cells at two different locations. Front Cell Neurosci 2023; 17:1186997. [PMID: 37565030 PMCID: PMC10411907 DOI: 10.3389/fncel.2023.1186997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 07/06/2023] [Indexed: 08/12/2023] Open
Abstract
Mechanosensory cells in the leech share several common features with mechanoreceptors in the human glabrous skin. Previous studies showed that the six T (touch) cells in each body segment of the leech are highly variable in their responses to somatic current injection and change their excitability over time. Here, we investigate three potential reasons for this variability in excitability by comparing the responses of T cells at two soma locations (T2 and T3): (1) Differential effects of time-dependent changes in excitability, (2) divergent synaptic input from the network, and (3) different anatomical structures. These hypotheses were explored with a combination of electrophysiological double recordings, 3D reconstruction of neurobiotin-filled cells, and compartmental model simulations. Current injection triggered significantly more spikes with shorter latency and larger amplitudes in cells at soma location T2 than at T3. During longer recordings, cells at both locations increased their excitability over time in the same way. T2 and T3 cells received the same amount of synaptic input from the unstimulated network, and the polysynaptic connections between both T cells were mutually symmetric. However, we found a striking anatomical difference: While in our data set all T2 cells innervated two roots connecting the ganglion with the skin, 50% of the T3 cells had only one root process. The sub-sample of T3 cells with one root process was significantly less excitable than the T3 cells with two root processes and the T2 cells. To test if the additional root process causes higher excitability, we simulated the responses of 3D reconstructed cells of both anatomies with detailed multi-compartment models. The anatomical subtypes do not differ in excitability when identical biophysical parameters and a homogeneous channel distribution are assumed. Hence, all three hypotheses may contribute to the highly variable T cell responses, but none of them is the only factor accounting for the observed systematic difference in excitability between cells at T2 vs. T3 soma location. Therefore, future patch clamp and modeling studies are needed to analyze how biophysical properties and spatial distribution of ion channels on the cell surface contribute to the variability and systematic differences of electrophysiological phenotypes.
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Affiliation(s)
- Sonja Meiser
- Department of Neuroscience, Computational Neuroscience, Faculty VI, University of Oldenburg, Oldenburg, Germany
| | - Jana Marie Sleeboom
- Department of Neuroscience, Computational Neuroscience, Faculty VI, University of Oldenburg, Oldenburg, Germany
- Institute of Physiology II, Faculty of Medicine, University Clinic Bonn (UKB), University of Bonn, Bonn, Germany
| | - Ihor Arkhypchuk
- Department of Neuroscience, Computational Neuroscience, Faculty VI, University of Oldenburg, Oldenburg, Germany
| | - Kevin Sandbote
- Department of Neuroscience, Computational Neuroscience, Faculty VI, University of Oldenburg, Oldenburg, Germany
| | - Jutta Kretzberg
- Department of Neuroscience, Computational Neuroscience, Faculty VI, University of Oldenburg, Oldenburg, Germany
- Department of Neuroscience, Cluster of Excellence Hearing4all, Faculty VI, University of Oldenburg, Oldenburg, Germany
- Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
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Ma X, Yan X, Ke R, Shan H, Rehman SU, Feng T, Zheng Y, Chuang C, Zhou W, Liu Q, Zheng J. Comparative Transcriptome Sequencing Analysis of Hirudo nipponia in Different Growth Periods. Front Physiol 2022; 13:873831. [PMID: 35812329 PMCID: PMC9259933 DOI: 10.3389/fphys.2022.873831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 06/02/2022] [Indexed: 11/13/2022] Open
Abstract
Hirudo nipponia is the only blood-sucking leech included in Chinese Pharmacopoeia having distinct features of anticoagulation, exorcizing blood stasis, and promoting menstruation. Despite such significant characteristics, very little is known about its molecular genetics and related physiological mechanisms. In this study, the transcriptomes of H. nipponia at three developmental stages (larvae, young, and adults), revealed a total of 1,348 differentially expressed genes (DEGs), 223 differentially expressed lncRNAs, and 88 novel mRNAs. A significant diverse gene expression patterns were observed at different developmental stages which were analyzed by differential gene expression trends, and the overall gene expression trends consist of three overall down-regulated trends, and two overall up-regulated trends. Furthermore, the GO and KEGG enrichment functional annotation analysis revealed that these DEGs were mainly associated with protein hydrolysis, signal transduction, energy metabolism, and lipid metabolism while growth, development, metabolism, and reproduction-related DEGs were also found. Additionally, real-time quantitative PCR results confirmed deep sequencing results based on the relative expression levels of nine randomly selected genes. This is the first transcriptome-based comprehensive study of H. irudo nipponia at different developmental stages which provided considerable deep understanding related to gene expression patterns and their relevant developmental pathways, neurodevelopmental and reproductive characteristics of the leech.
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Affiliation(s)
- Xiaocong Ma
- Department of Cardiology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Xiuying Yan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Ren Ke
- Department of Cardiology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Huiquan Shan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Saif ur Rehman
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Tong Feng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Yalin Zheng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Chen Chuang
- Guangxi Medical University Cancer Hospital, Nanning, China
| | - Weiguan Zhou
- Thai Natural Hirudin Co, Ltd., Bangkok, Thailand
| | - Qingyou Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
- Guangdong Provincial Key Laboratory of Animal Molecular Design and Precise Breeding, School of Life Science and Engineering, Foshan University, Foshan, China
- *Correspondence: Qingyou Liu, ; Jinghui Zheng,
| | - Jinghui Zheng
- Department of Cardiology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
- *Correspondence: Qingyou Liu, ; Jinghui Zheng,
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Shan H, Ren K, Liu J, Rehman SU, Yan X, Ma X, Zheng Y, Feng T, Wang X, Li Z, Zhou W, Chuang C, Liang M, Zheng J, Liu Q. Comprehensive Transcriptome Sequencing Analysis of Hirudinaria manillensis in Different Growth Periods. Front Physiol 2022; 13:897458. [PMID: 35694407 PMCID: PMC9174698 DOI: 10.3389/fphys.2022.897458] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 04/22/2022] [Indexed: 02/04/2023] Open
Abstract
Medical leeches are widely been used in biochemical and clinical medical studies, helping to restore blood circulation to grafted or severely injured tissue. Mostly, adult leeches are being used in the traditional pharmacopeia, but the gene expression profiling of leeches in different growth periods is not well-reported. So, in this study, we used transcriptome analysis to analyze the comparative gene expression patterns of Hirudinaria manillensis (H. manillensis) in different growth periods, including larval, young, and adult stages. We constructed 24 cDNA libraries from H. manillensis larval, young, and adult stages, and about 54,639,118 sequences were generated, 18,106 mRNA transcripts of which 958 novel mRNAs and 491 lncRNAs were also assembled as well. Furthermore, the results of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that the differentially upregulated genes from the larval to adult stages were enriched in pathways such as cilium, myofibril, contractile fiber, cytoskeleton proteins, dilated cardiomyopathy, adrenergic signaling in cardiomyocytes, etc. Moreover, in the adult stages, a significant increase in the expression of the Hirudin-HM (HIRM2) genes was detected. In addition, our comparative transcriptome profiling data from different growth stages of H. manillensis also identified a large number of DEGs and DElncRNAs which were tentatively found to be associated with the growth of H. manillensis; as it grew, the muscle-related gene expression increased, while the lipid metabolism and need for stimulation and nutrition-related genes decreased. Similarly, the higher expression of HIRM2 might attribute to the high expression of protein disulfide isomerase gene family (PDI) family genes in adulthood, which provides an important clue that why adult leeches rather than young leeches are widely used in clinical therapeutics and traditional Chinese medicine.
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Affiliation(s)
- Huiquan Shan
- Guangdong Provincial Key Laboratory of Animal Molecular Design and Precise Breeding, School of Life Science and Engineering, Foshan University, Foshan, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro- Bioresources, Guangxi University, Nanning, China
| | - Ke Ren
- Department of Cardiology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Jiasheng Liu
- Department of Cardiology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Saif ur Rehman
- State Key Laboratory for Conservation and Utilization of Subtropical Agro- Bioresources, Guangxi University, Nanning, China
| | - Xiuying Yan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro- Bioresources, Guangxi University, Nanning, China
| | - Xiaocong Ma
- Department of Cardiology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Yalin Zheng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro- Bioresources, Guangxi University, Nanning, China
| | - Tong Feng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro- Bioresources, Guangxi University, Nanning, China
| | - Xiaobo Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro- Bioresources, Guangxi University, Nanning, China
| | - Zhipeng Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro- Bioresources, Guangxi University, Nanning, China
| | - Weiguan Zhou
- THAI Natural Hirudin Co., Ltd., Bangkok, Thailand
| | - Chen Chuang
- Guangxi Medical University Cancer Hospital, Nanning, China
| | - Mingkun Liang
- Department of Cardiology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - Jinghui Zheng
- Department of Cardiology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
- *Correspondence: Jinghui Zheng, ; Qingyou Liu,
| | - Qingyou Liu
- Guangdong Provincial Key Laboratory of Animal Molecular Design and Precise Breeding, School of Life Science and Engineering, Foshan University, Foshan, China
- *Correspondence: Jinghui Zheng, ; Qingyou Liu,
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Scherer JS, Riedesel OE, Arkhypchuk I, Meiser S, Kretzberg J. Initial Variability and Time-Dependent Changes of Neuronal Response Features Are Cell-Type-Specific. Front Cell Neurosci 2022; 16:858221. [PMID: 35573827 PMCID: PMC9092978 DOI: 10.3389/fncel.2022.858221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 03/16/2022] [Indexed: 11/13/2022] Open
Abstract
Different cell types are commonly defined by their distinct response features. But several studies proved substantial variability between cells of the same type, suggesting rather the appraisal of response feature distributions than a limitation to "typical" responses. Moreover, there is growing evidence that time-dependent changes of response features contribute to robust and functional network output in many neuronal systems. The individually characterized Touch (T), Pressure (P), and Retzius (Rz) cells in the medicinal leech allow for a rigid analysis of response features, elucidating differences between and variability within cell types, as well as their changes over time. The initial responses of T and P cells to somatic current injection cover a wide range of spike counts, and their first spike is generated with a high temporal precision after a short latency. In contrast, all Rz cells elicit very similar low spike counts with variable, long latencies. During prolonged electrical stimulation the resting membrane potential of all three cell types hyperpolarizes. At the same time, Rz cells reduce their spiking activity as expected for a departure from the spike threshold. In contrast, both mechanoreceptor types increase their spike counts during repeated stimulation, consistent with previous findings in T cells. A control experiment reveals that neither a massive current stimulation nor the hyperpolarization of the membrane potential is necessary for the mechanoreceptors' increase in excitability over time. These findings challenge the previously proposed involvement of slow K+-channels in the time-dependent activity changes. We also find no indication for a run-down of HCN channels over time, and a rigid statistical analysis contradicts several potential experimental confounders as the basis of the observed variability. We conclude that the time-dependent change in excitability of T and P cells could indicate a cell-type-specific shift between different spiking regimes, which also could explain the high variability in the initial responses. The underlying mechanism needs to be further investigated in more naturalistic experimental situations to disentangle the effects of varying membrane properties versus network interactions. They will show if variability in individual response features serves as flexible adaptation to behavioral contexts rather than just "randomness".
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Affiliation(s)
- Jens-Steffen Scherer
- Computational Neuroscience, Department of Neuroscience, Faculty VI, University of Oldenburg, Oldenburg, Germany
| | - Oda E. Riedesel
- Computational Neuroscience, Department of Neuroscience, Faculty VI, University of Oldenburg, Oldenburg, Germany
| | - Ihor Arkhypchuk
- Computational Neuroscience, Department of Neuroscience, Faculty VI, University of Oldenburg, Oldenburg, Germany
| | - Sonja Meiser
- Computational Neuroscience, Department of Neuroscience, Faculty VI, University of Oldenburg, Oldenburg, Germany
| | - Jutta Kretzberg
- Computational Neuroscience, Department of Neuroscience, Faculty VI, University of Oldenburg, Oldenburg, Germany
- Cluster of Excellence Hearing4all, Department of Neuroscience, Faculty VI, University of Oldenburg, Oldenburg, Germany
- Research Center Neurosensory Science, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
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Invertebrate neurons as a simple model to study the hyperexcitable state of epileptic disorders in single cells, monosynaptic connections, and polysynaptic circuits. Biophys Rev 2022; 14:553-568. [PMID: 35528035 PMCID: PMC9043075 DOI: 10.1007/s12551-022-00942-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 03/09/2022] [Indexed: 12/17/2022] Open
Abstract
Epilepsy is a neurological disorder characterized by a hyperexcitable state in neurons from different brain regions. Much is unknown about epilepsy and seizures development, depicting a growing field of research. Animal models have provided important clues about the underlying mechanisms of seizure-generating neuronal circuits. Mammalian complexity still makes it difficult to define some principles of nervous system function, and non-mammalian models have played pivotal roles depending on the research question at hand. Mollusks and the Helix land snail have been used to study epileptic-like behavior in neurons. Neurons from these organisms confer advantages as single-cell identification, isolation, and culture, either as single cells or as physiological relevant monosynaptic or polysynaptic circuits, together with amenability to different protocols and treatments. This review's purpose consists in presenting relevant papers in order to gain a better understanding of Helix neurons, their characteristics, uses, and capabilities for studying the fundamental mechanisms of epileptic disorders and their treatment, to facilitate their more expansive use in epilepsy research.
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