1
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Geva N, Deitch D, Rubin A, Ziv Y. Time and experience differentially affect distinct aspects of hippocampal representational drift. Neuron 2023:S0896-6273(23)00378-1. [PMID: 37315556 DOI: 10.1016/j.neuron.2023.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [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: 09/22/2022] [Revised: 02/22/2023] [Accepted: 05/08/2023] [Indexed: 06/16/2023]
Abstract
Hippocampal activity is critical for spatial memory. Within a fixed, familiar environment, hippocampal codes gradually change over timescales of days to weeks-a phenomenon known as representational drift. The passage of time and the amount of experience are two factors that profoundly affect memory. However, thus far, it has remained unclear to what extent these factors drive hippocampal representational drift. Here, we longitudinally recorded large populations of hippocampal neurons in mice while they repeatedly explored two different familiar environments that they visited at different time intervals over weeks. We found that time and experience differentially affected distinct aspects of representational drift: the passage of time drove changes in neuronal activity rates, whereas experience drove changes in the cells' spatial tuning. Changes in spatial tuning were context specific and largely independent of changes in activity rates. Thus, our results suggest that representational drift is a multi-faceted process governed by distinct neuronal mechanisms.
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Affiliation(s)
- Nitzan Geva
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Daniel Deitch
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Alon Rubin
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel.
| | - Yaniv Ziv
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel.
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2
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Sheintuch L, Geva N, Deitch D, Rubin A, Ziv Y. Organization of hippocampal CA3 into correlated cell assemblies supports a stable spatial code. Cell Rep 2023; 42:112119. [PMID: 36807137 PMCID: PMC9989830 DOI: 10.1016/j.celrep.2023.112119] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [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: 09/15/2022] [Revised: 11/30/2022] [Accepted: 01/30/2023] [Indexed: 02/19/2023] Open
Abstract
Hippocampal subfield CA3 is thought to stably store memories in assemblies of recurrently connected cells functioning as a collective. However, the collective hippocampal coding properties that are unique to CA3 and how such properties facilitate the stability or precision of the neural code remain unclear. Here, we performed large-scale Ca2+ imaging in hippocampal CA1 and CA3 of freely behaving mice that repeatedly explored the same, initially novel environments over weeks. CA3 place cells have more precise and more stable tuning and show a higher statistical dependence with their peers compared with CA1 place cells, uncovering a cell assembly organization in CA3. Surprisingly, although tuning precision and long-term stability are correlated, cells with stronger peer dependence exhibit higher stability but not higher precision. Overall, our results expose the three-way relationship between tuning precision, long-term stability, and peer dependence, suggesting that a cell assembly organization underlies long-term storage of information in the hippocampus.
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Affiliation(s)
- Liron Sheintuch
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Nitzan Geva
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Daniel Deitch
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Alon Rubin
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel.
| | - Yaniv Ziv
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel.
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3
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Liu Y, Levy S, Mau W, Geva N, Rubin A, Ziv Y, Hasselmo M, Howard M. Consistent population activity on the scale of minutes in the mouse hippocampus. Hippocampus 2022; 32:359-372. [PMID: 35225408 PMCID: PMC10085730 DOI: 10.1002/hipo.23409] [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: 07/19/2021] [Revised: 01/05/2022] [Accepted: 01/31/2022] [Indexed: 11/09/2022]
Abstract
Neurons in the hippocampus fire in consistent sequence over the timescale of seconds during the delay period of some memory experiments. For longer timescales, the firing of hippocampal neurons also changes slowly over minutes within experimental sessions. It was thought that these slow dynamics are caused by stochastic drift or a continuous change in the representation of the episode, rather than consistent sequences unfolding over minutes. This paper studies the consistency of contextual drift in three chronic calcium imaging recordings from the hippocampus CA1 region in mice. Computational measures of consistency show reliable sequences within experimental trials at the scale of seconds as one would expect from time cells or place cells during the trial, as well as across experimental trials on the scale of minutes within a recording session. Consistent sequences in the hippocampus are observed over a wide range of time scales, from seconds to minutes. The hippocampal activity could reflect a scale-invariant spatiotemporal context as suggested by theories of memory from cognitive psychology.
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Affiliation(s)
- Yue Liu
- Department of Physics, Boston University, Boston, Massachusetts, USA.,Center for Systems Neuroscience, Boston University, Boston, Massachusetts, USA.,Center for Memory and Brain, Boston University, Boston, Massachusetts, USA
| | - Samuel Levy
- Center for Systems Neuroscience, Boston University, Boston, Massachusetts, USA.,Center for Memory and Brain, Boston University, Boston, Massachusetts, USA.,Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, USA
| | - William Mau
- Center for Systems Neuroscience, Boston University, Boston, Massachusetts, USA.,Center for Memory and Brain, Boston University, Boston, Massachusetts, USA.,Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, USA
| | - Nitzan Geva
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Alon Rubin
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Yaniv Ziv
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Michael Hasselmo
- Center for Systems Neuroscience, Boston University, Boston, Massachusetts, USA.,Center for Memory and Brain, Boston University, Boston, Massachusetts, USA.,Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, USA
| | - Marc Howard
- Department of Physics, Boston University, Boston, Massachusetts, USA.,Center for Systems Neuroscience, Boston University, Boston, Massachusetts, USA.,Center for Memory and Brain, Boston University, Boston, Massachusetts, USA.,Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, USA
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4
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Zarhin D, Atsmon R, Ruggiero A, Baeloha H, Shoob S, Scharf O, Heim LR, Buchbinder N, Shinikamin O, Shapira I, Styr B, Braun G, Harel M, Sheinin A, Geva N, Sela Y, Saito T, Saido T, Geiger T, Nir Y, Ziv Y, Slutsky I. Disrupted neural correlates of anesthesia and sleep reveal early circuit dysfunctions in Alzheimer models. Cell Rep 2022; 38:110268. [PMID: 35045289 PMCID: PMC8789564 DOI: 10.1016/j.celrep.2021.110268] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 12/06/2021] [Accepted: 12/22/2021] [Indexed: 11/30/2022] Open
Abstract
Dysregulated homeostasis of neural activity has been hypothesized to drive Alzheimer's disease (AD) pathogenesis. AD begins with a decades-long presymptomatic phase, but whether homeostatic mechanisms already begin failing during this silent phase is unknown. We show that before the onset of memory decline and sleep disturbances, familial AD (fAD) model mice display no deficits in CA1 mean firing rate (MFR) during active wakefulness. However, homeostatic down-regulation of CA1 MFR is disrupted during non-rapid eye movement (NREM) sleep and general anesthesia in fAD mouse models. The resultant hyperexcitability is attenuated by the mitochondrial dihydroorotate dehydrogenase (DHODH) enzyme inhibitor, which tunes MFR toward lower set-point values. Ex vivo fAD mutations impair downward MFR homeostasis, resulting in pathological MFR set points in response to anesthetic drug and inhibition blockade. Thus, firing rate dyshomeostasis of hippocampal circuits is masked during active wakefulness but surfaces during low-arousal brain states, representing an early failure of the silent disease stage.
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Affiliation(s)
- Daniel Zarhin
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Refaela Atsmon
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Antonella Ruggiero
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Halit Baeloha
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Shiri Shoob
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Oded Scharf
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Leore R Heim
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nadav Buchbinder
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ortal Shinikamin
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ilana Shapira
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Boaz Styr
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Gabriella Braun
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Michal Harel
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Anton Sheinin
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nitzan Geva
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yaniv Sela
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Saitama 351-0198, Japan; Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi 467-8601, Japan
| | - Takaomi Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Saitama 351-0198, Japan
| | - Tamar Geiger
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yuval Nir
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yaniv Ziv
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Inna Slutsky
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel.
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5
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Sheintuch L, Geva N, Baumer H, Rechavi Y, Rubin A, Ziv Y. Multiple Maps of the Same Spatial Context Can Stably Coexist in the Mouse Hippocampus. Curr Biol 2020; 30:1467-1476.e6. [PMID: 32220328 DOI: 10.1016/j.cub.2020.02.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [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: 12/03/2019] [Revised: 01/15/2020] [Accepted: 02/07/2020] [Indexed: 11/29/2022]
Abstract
Hippocampal place cells selectively fire when an animal traverses a particular location and are considered a neural substrate of spatial memory. Place cells were shown to change their activity patterns (remap) across different spatial contexts but to maintain their spatial tuning in a fixed familiar context. Here, we show that mouse hippocampal neurons can globally remap, forming multiple distinct representations (maps) of the same familiar environment, without any apparent changes in sensory input or behavior. Alternations between maps occurred only across separate visits to the environment, implying switching between distinct stable attractors in the hippocampal network. Importantly, the different maps were spatially informative and persistent over weeks, demonstrating that they can be reliably stored and retrieved from long-term memory. Taken together, our results suggest that a memory of a given spatial context could be associated with multiple distinct neuronal representations, rather than just one.
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Affiliation(s)
- Liron Sheintuch
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Nitzan Geva
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Hadas Baumer
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yoav Rechavi
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Alon Rubin
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
| | - Yaniv Ziv
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
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6
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Gotlieb R, Abitbol J, How JA, Ben-Brith I, Abenhaim HA, Lau SK, Basik M, Rosberger Z, Geva N, Gotlieb WH, Mintz A. Gender differences in how physicians access and process information. Gynecol Oncol Rep 2019; 27:50-53. [PMID: 30662932 PMCID: PMC6325067 DOI: 10.1016/j.gore.2018.12.008] [Citation(s) in RCA: 3] [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] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 12/18/2018] [Accepted: 12/22/2018] [Indexed: 11/13/2022] Open
Abstract
There is an absence of information on how physicians make surgical decisions, and on the effect of gender on the processing of information. A novel web based decision-matrix software was designed to trace experimentally the process of decision making in medical situations. The scenarios included a crisis and non-crisis simulation for endometrial cancer surgery. Gynecologic oncologists, fellows, and residents (42 male and 42 female) in Canada participated in this experiment. Overall, male physicians used more heuristics, whereas female physicians were more comprehensive in accessing clinical information (p < 0.03), utilized alternative-based acquisition processes in the non-crisis scenario (p = 0.01), were less likely to consider procedure-related costs (p = 0.04), and overall allocated more time to evaluate the information (p < 0.01). Further experiments leading to a better understanding of the cognitive processes involved in medical decision making could influence education and training and impact on patient outcome. Novel software evaluating how physicians make decisions in clinical scenarios. Significant differences exist in how male and female surgeons access information and make decisions. Male physicians used more heuristics and made quicker decisions. Female physicians were more comprehensive, and took more time to evaluate information.
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Affiliation(s)
- R Gotlieb
- Division of Experimental Surgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada.,Division of Gynecologic Oncology, Segal Cancer Center, Jewish General Hospital, McGill University, Canada
| | - J Abitbol
- Division of Gynecologic Oncology, Segal Cancer Center, Jewish General Hospital, McGill University, Canada.,Lady Davis Research Institute, Segal Cancer Center, McGill University, Montreal, Quebec, Canada
| | - J A How
- Division of Gynecologic Oncology, Segal Cancer Center, Jewish General Hospital, McGill University, Canada.,Department of Obstetrics and Gynecology, Jewish General Hospital, McGill University, Canada
| | - I Ben-Brith
- Division of Gynecologic Oncology, Segal Cancer Center, Jewish General Hospital, McGill University, Canada
| | - H A Abenhaim
- Division of Experimental Surgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada.,Department of Obstetrics and Gynecology, Jewish General Hospital, McGill University, Canada
| | - S K Lau
- Division of Gynecologic Oncology, Segal Cancer Center, Jewish General Hospital, McGill University, Canada.,Lady Davis Research Institute, Segal Cancer Center, McGill University, Montreal, Quebec, Canada
| | - M Basik
- Division of Experimental Surgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada.,Department of General Surgery, McGill University, Montreal, QC H3T 1E2, Canada
| | - Z Rosberger
- Psychology Division, Department of Psychiatry, Sir Mortimer B. Davis-Jewish General Hospital, Canada
| | - N Geva
- Department of Political Science, Texas A&M University, USA
| | - W H Gotlieb
- Division of Experimental Surgery, Faculty of Medicine, McGill University, Montreal, Quebec, Canada.,Division of Gynecologic Oncology, Segal Cancer Center, Jewish General Hospital, McGill University, Canada
| | - A Mintz
- Lauder School of Government, Diplomacy and Strategy, IDC, Israel
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7
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Sheintuch L, Rubin A, Brande-Eilat N, Geva N, Sadeh N, Pinchasof O, Ziv Y. Tracking the Same Neurons across Multiple Days in Ca 2+ Imaging Data. Cell Rep 2018; 21:1102-1115. [PMID: 29069591 PMCID: PMC5670033 DOI: 10.1016/j.celrep.2017.10.013] [Citation(s) in RCA: 150] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 08/14/2017] [Accepted: 10/03/2017] [Indexed: 12/28/2022] Open
Abstract
Ca2+ imaging techniques permit time-lapse recordings of neuronal activity from large populations over weeks. However, without identifying the same neurons across imaging sessions (cell registration), longitudinal analysis of the neural code is restricted to population-level statistics. Accurate cell registration becomes challenging with increased numbers of cells, sessions, and inter-session intervals. Current cell registration practices, whether manual or automatic, do not quantitatively evaluate registration accuracy, possibly leading to data misinterpretation. We developed a probabilistic method that automatically registers cells across multiple sessions and estimates the registration confidence for each registered cell. Using large-scale Ca2+ imaging data recorded over weeks from the hippocampus and cortex of freely behaving mice, we show that our method performs more accurate registration than previously used routines, yielding estimated error rates <5%, and that the registration is scalable for many sessions. Thus, our method allows reliable longitudinal analysis of the same neurons over long time periods. A method for tracking neurons across days (cell registration) in Ca2+ imaging data The method is probabilistic and quantitatively evaluates registration accuracy The method is applicable to various imaging techniques and cell detection algorithms Registration accuracy remains high with an increased number of registered sessions
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Affiliation(s)
- Liron Sheintuch
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Alon Rubin
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Noa Brande-Eilat
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Nitzan Geva
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Noa Sadeh
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Or Pinchasof
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yaniv Ziv
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
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8
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Brill S, Sprecher E, Smith FJD, Geva N, Gruener H, Nahman-Averbuch H, Defrin R. Chronic pain in pachyonychia congenita: evidence for neuropathic origin. Br J Dermatol 2018; 179:154-162. [PMID: 29210461 DOI: 10.1111/bjd.16217] [Citation(s) in RCA: 17] [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] [Accepted: 11/28/2017] [Indexed: 12/25/2022]
Abstract
BACKGROUND Pachyonychia congenita (PC) is a rare autosomal dominant skin disease, with chronic pain being the most prominent complaint. Histological studies showing alterations in sensory innervation, along with reports on alterations in mechanical sensitivity, suggest that PC may be a form of neuropathy. OBJECTIVES Here, for the first time, we aim to evaluate systematically the sensory function of patients with PC vs. controls, in order to investigate the pathophysiology of PC. METHODS Patients (n = 62) and controls (n = 45) completed the McGill and Douleur Neuropathique-4 (DN4) questionnaires. Sensory testing included detection and pain thresholds, pathological sensations, conditioned pain modulation (CPM) and temporal summation of pain. RESULTS A moderate-to-severe chronic pain in the feet, throbbing and stabbing in quality, was highly prevalent among patients with PC (86%) and was especially debilitating during weight bearing. In addition, the majority of patients had a DN4 score ≥ 4 (62%), static allodynia (55%) and tingling (53%) in the feet. Compared with controls, patients with PC exhibited thermal and mechanical hypoaesthesia and mechanical hyperalgesia in the feet. CPM was reduced among the patients, and was associated with more enhanced mechanical hyperalgesia in the feet. The specific gene and nature of the causative mutation did not affect any of these features. CONCLUSIONS Although thermal and mechanical hypoaesthesia may result from thicker skin, its presentation in painful regions, along with mechanical hyperalgesia and allodynia, point towards the possibility of neuropathic changes occurring in PC. The clinical features and DN4 scores support this possibility and therefore neuropathic pain medications may be beneficial for patients with PC.
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Affiliation(s)
- S Brill
- Center for Pain Medicine, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel
| | - E Sprecher
- Department of Dermatology, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel.,Department of Dermatology, Tel-Aviv University, Tel-Aviv, 69978, Israel
| | - F J D Smith
- Pachyonychia Congenita Project, School of Life Sciences, University of Dundee, Dundee, U.K
| | - N Geva
- Department of Physical Therapy, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978, Israel.,Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, 69978, Israel
| | - H Gruener
- Department of Physical Therapy, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978, Israel.,Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, 69978, Israel
| | - H Nahman-Averbuch
- Department of Anesthesia, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, U.S.A
| | - R Defrin
- Department of Physical Therapy, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, 69978, Israel.,Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, 69978, Israel
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9
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Abstract
The capacity to remember temporal relationships between different events is essential to episodic memory, but little is currently known about its underlying mechanisms. We performed time-lapse imaging of thousands of neurons over weeks in the hippocampal CA1 of mice as they repeatedly visited two distinct environments. Longitudinal analysis exposed ongoing environment-independent evolution of episodic representations, despite stable place field locations and constant remapping between the two environments. These dynamics time-stamped experienced events via neuronal ensembles that had cellular composition and activity patterns unique to specific points in time. Temporally close episodes shared a common timestamp regardless of the spatial context in which they occurred. Temporally remote episodes had distinct timestamps, even if they occurred within the same spatial context. Our results suggest that days-scale hippocampal ensemble dynamics could support the formation of a mental timeline in which experienced events could be mnemonically associated or dissociated based on their temporal distance. DOI:http://dx.doi.org/10.7554/eLife.12247.001 The ability to recall the timing of events is an important feature of long-term memory. Episodic memory, the mental account of “what” happened, “where” and “when”, depends on a region of a brain called the hippocampus. Certain neurons in the hippocampus, called place-cells, are known to capture information about the locations an animal has visited so that a specific pattern of place cell activity marks each location an animal visits. However, it is not clear how the brain can mark the relationship between the timing of different events. Some studies have documented gradual changes in the activity patterns of the place cells over time, which could help mark time. If these changes are specific to a particular environment then they would not allow animals to associate in memory events that occurred close in time (for instance, in the same day) if these events occurred in different environments. To do that, a certain component of the changes in the activity patterns would have to be independent of any specific environment or context in which events occur. Now, Rubin, Geva et al. have captured time-lapse images of the activity of thousands of hippocampal cells in mice as they explored two different environments on repeated occasions over a two-week period. The environments had different shapes, textures, visual cues, and odors. The mice were allowed to explore each environment daily for more than a week prior to the time-lapse filming so that they would be very familiar with the two environments. During the filming portion of the experiments, the mice visited one environment in the morning, and then the other in the afternoon. The analysis of the images revealed what appeared to be unique patterns of cell activity for specific days, which gradually changed over the course of the experiment. The patterns persisted even when the animals switched to a new environment during the same day, but were different for visits to the same environment on different days. Next, Rubin, Geva et al. used the patterns of activity collected from the mice while they were in one environment to create a timeline of events. From this timeline, it was possible to accurately deduce which day each visit to the other environment occurred based on the patterns of hippocampal cell activity alone. One challenge that stems from this work is to understand the biological mechanisms that drive the patterns in neuronal activity over timescales that are relevant for long-term memory. DOI:http://dx.doi.org/10.7554/eLife.12247.002
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Affiliation(s)
- Alon Rubin
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Nitzan Geva
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Liron Sheintuch
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Yaniv Ziv
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
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10
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Lucas C, Kornfein R, Chakaborty-Chatterjee M, Schonfeld J, Geva N, Sokolowski MB, Ayali A. The locust foraging gene. Arch Insect Biochem Physiol 2010; 74:52-66. [PMID: 20422718 DOI: 10.1002/arch.20363] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Our knowledge of how genes act on the nervous system in response to the environment to generate behavioral plasticity is limited. A number of recent advancements in this area concern food-related behaviors and a specific gene family called foraging (for), which encodes a cGMP-dependent protein kinase (PKG). The desert locust (Schistocerca gregaria) is notorious for its destructive feeding and long-term migratory behavior. Locust phase polyphenism is an extreme example of environmentally induced behavioral plasticity. In response to changes in population density, locusts dramatically alter their behavior, from solitary and relatively sedentary behavior to active aggregation and swarming. Very little is known about the molecular and genetic basis of this striking behavioral phenomenon. Here we initiated studies into the locust for gene by identifying, cloning, and studying expression of the gene in the locust brain. We determined the phylogenetic relationships between the locust PKG and other known PKG proteins in insects. FOR expression was found to be confined to neurons of the anterior midline of the brain, the pars intercerebralis. Our results suggest that differences in PKG enzyme activity are correlated to well-established phase-related behavioral differences. These results lay the groundwork for functional studies of the locust for gene and its possible relations to locust phase polyphenism.
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Affiliation(s)
- C Lucas
- Department of Biology, University of Toronto, Mississauga, Ontario, Canada
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11
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Geva N, Guershon M, Orlova M, Ayali A. Memoirs of a locust: density-dependent behavioral change as a model for learning and memory. Neurobiol Learn Mem 2009; 93:175-82. [PMID: 19766727 DOI: 10.1016/j.nlm.2009.09.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 09/10/2009] [Accepted: 09/14/2009] [Indexed: 10/20/2022]
Abstract
A locust outbreak is a stupendous natural phenomenon that remains in the memory of whoever has been lucky (or unlucky) enough to witness it. Recent years have provided novel and important insights into the neurobiology of locust swarming. However, the central nervous system processes that accompany and perhaps even lie at the basis of locust phase transformation are still far from being fully understood. Our current work deals with the memory of a locust outbreak from a new perspective: that of the individual locust. We take locust density-dependent phase transformation - a unique example of extreme behavioral plasticity, and place it within the context of the accepted scheme of learning and memory. We confirm that a short time period of exposure to a small crowd of locusts is sufficient to induce a significant behavioral change in a previously solitary locust. Our results suggest that part of the behavioral change is due to long-term habituation of evasive and escape responses. We further demonstrate that the memory of a crowding event lasts for at least 24h, and that this memory is sensitive to a protein synthesis blocker. These findings add much to our understanding of locust density-dependent phase polyphenism. Furthermore, they offer a novel and tractable model for the study of learning and memory-related processes in a very distinctive behavioral context.
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Affiliation(s)
- N Geva
- Department of Zoology, Tel Aviv University, Tel Aviv 69978, Israel
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Eilenberg H, Beer S, Gepstein S, Geva N, Tadmor O, Zilberstein A. Variability in Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase Small Subunits and Carboxylation Activity in Fern Gametophytes Grown under Different Light Spectra. Plant Physiol 1991; 95:298-304. [PMID: 16667969 PMCID: PMC1077522 DOI: 10.1104/pp.95.1.298] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Two distinct ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) small subunit (SSU) populations were observed in Pteris vittata gametophytes grown under different illumination conditions. Exposure of the fern gametophytes to continuous red light (R) resulted in Rubisco SSUs that were not recognized by polyclonal antibodies raised against SSUs from spinach. Unlike the R-induced SSUs, blue light (B) induced SSUs were well recognized. This difference in SSU composition also reflected in Rubisco activity. In vitro, B-induced Rubisco exhibits a significantly higher carboxylation activity as compared to the R-induced Rubisco. Approximately a two- to threefold increase in the V(max) value of the B-induced carboxylase as compared to the R-induced one was measured. It thus seems very likely that certain domains in the SSU molecule affect enzyme activity.
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Affiliation(s)
- H Eilenberg
- Department of Botany, Tel Aviv University, Ramat Aviv, 69978 Tel Aviv, Israel
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Shoham SG, Geva N, Kliger D, Chai T. Drug abuse among Israeli youth: epidemiological pilot study. Bull Narc 1974; 26:9-28. [PMID: 4496817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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