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Homayouni R, Daugherty AM, Yu Q, Raz N, Ofen N. KIBRA single nucleotide polymorphism is associated with hippocampal subfield volumes and cognition across development. Brain Struct Funct 2024; 229:223-230. [PMID: 37853296 DOI: 10.1007/s00429-023-02716-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 09/21/2023] [Indexed: 10/20/2023]
Abstract
The hippocampus (Hc) consists of cytoarchitectonically and functionally distinct subfields: dentate gyrus (DG), cornu ammonis (CA1-3), and subiculum. In adults, a single nucleotide polymorphism (rs17070145, C→ T) in KIBRA, a gene encoding the eponymous (KIdney-BRAin) protein, is associated with variability in Hc subfield volumes and episodic memory. T-allele carriers have larger DG and CA volumes and better episodic memory compared to C-homozygotes. Little is known, however, about KIBRA's role in the development of the brain and cognition. In a sample of children, adolescents, and young adults (N = 176, ages 5- 25 years), we replicated the adult association between KIBRA T-allele and larger DG and CA volumes but observed no relationship between KIBRA rs17070145 polymorphism and episodic memory. We noted, however, that a general cognitive performance index (IQ) differed across the allelic groups, with the lowest scores among T-homozygotes and the highest among C-homozygotes. Thus, in this developmental sample, KIBRA appears to have opposing effects on regional brain volume and cognition. These influences of KIBRA SNP may stem from associations between developmental reduction in brain volume and gains in cognitive performance-a hypothesis to be tested in longitudinal studies.
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Affiliation(s)
- Roya Homayouni
- Institute of Gerontology, Wayne State University, Detroit, MI, USA
- Department of Psychology, Wayne State University, Detroit, MI, USA
| | - Ana M Daugherty
- Institute of Gerontology, Wayne State University, Detroit, MI, USA
- Department of Psychology, Wayne State University, Detroit, MI, USA
| | - Qijing Yu
- Institute of Gerontology, Wayne State University, Detroit, MI, USA
| | - Naftali Raz
- Department of Psychology, Stony Brook University, Stony Brook, NY, USA
| | - Noa Ofen
- Institute of Gerontology, Wayne State University, Detroit, MI, USA.
- Department of Psychology, Wayne State University, Detroit, MI, USA.
- Merrill Palmer Skillman Institute, Wayne State University, Detroit, MI, USA.
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Homayouni R, Canada KL, Saifullah S, Foster DJ, Thill C, Raz N, Daugherty AM, Ofen N. Age-related differences in hippocampal subfield volumes across the human lifespan: A meta-analysis. Hippocampus 2023; 33:1292-1315. [PMID: 37881160 PMCID: PMC10841547 DOI: 10.1002/hipo.23582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 08/31/2023] [Accepted: 09/28/2023] [Indexed: 10/27/2023]
Abstract
The human hippocampus (Hc) is critical for memory function across the lifespan. It is comprised of cytoarchitectonically distinct subfields: dentate gyrus (DG), cornu ammonis sectors (CA) 1-4, and subiculum, each of which may be differentially susceptible to neurodevelopmental and neurodegenerative mechanisms. Identifying age-related differences in Hc subfield volumes can provide insights into neural mechanisms of memory function across the lifespan. Limited evidence suggests that DG and CA3 volumes differ across development while other regions remain relatively stable, and studies of adulthood implicate a downward trend in all subfield volumes with prominent age effects on CA1. Due to differences in methods and limited sampling for any single study, the magnitude of age effects on Hc subfield volumes and their probable lifespan trajectories remain unclear. Here, we conducted a meta-analysis on cross-sectional studies (n = 48,278 participants, ages = 4-94 years) to examine the association between age and Hc subfield volumes in development (n = 11 studies), adulthood (n = 30 studies), and a combined lifespan sample (n = 41 studies) while adjusting estimates for sample sizes. In development, age was positively associated with DG and CA3-4 volumes, whereas in adulthood a negative association was observed with all subfield volumes. Notably, the observed age effects were not different across subfield volumes within each age group. All subfield volumes showed a nonlinear age pattern across the lifespan with DG and CA3-4 volumes showing a more distinct age trajectory as compared to the other subfields. Lastly, among all the study-level variables, only female percentage of the study sample moderated the age effect on CA1 volume: a higher female-to-male ratio in the study sample was linked to the greater negative association between age and CA1 volume. These results document that Hc subfield volumes differ as a function of age offering broader implications for constructing theoretical models of lifespan memory development.
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Affiliation(s)
- Roya Homayouni
- Institute of Gerontology, Wayne State University, Detroit, Michigan, USA
- Department of Psychology, Wayne State University, Detroit, Michigan, USA
| | - Kelsey L Canada
- Institute of Gerontology, Wayne State University, Detroit, Michigan, USA
| | - Samaah Saifullah
- School of Medicine, Wayne State University, Detroit, Michigan, USA
| | - Da' Jonae Foster
- Department of Psychology, Wayne State University, Detroit, Michigan, USA
| | - Charlotte Thill
- School of Medicine, Wayne State University, Detroit, Michigan, USA
| | - Naftali Raz
- Department of Psychology, Stony Brook University, Stony Brook, New York, USA
- Max Planck Institute for Human Development, Berlin, Germany
| | - Ana M Daugherty
- Institute of Gerontology, Wayne State University, Detroit, Michigan, USA
- Department of Psychology, Wayne State University, Detroit, Michigan, USA
| | - Noa Ofen
- Institute of Gerontology, Wayne State University, Detroit, Michigan, USA
- Department of Psychology, Wayne State University, Detroit, Michigan, USA
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Platholi J, Marongiu R, Park L, Yu F, Sommer G, Weinberger R, Tower W, Milner TA, Glass MJ. Hippocampal glial inflammatory markers are differentially altered in a novel mouse model of perimenopausal cerebral amyloid angiopathy. Front Aging Neurosci 2023; 15:1280218. [PMID: 38035277 PMCID: PMC10684955 DOI: 10.3389/fnagi.2023.1280218] [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: 08/19/2023] [Accepted: 10/27/2023] [Indexed: 12/02/2023] Open
Abstract
Dementia is often characterized by age-dependent cerebrovascular pathology, neuroinflammation, and cognitive deficits with notable sex differences in risk, disease onset, progression and severity. Women bear a disproportionate burden of dementia, and the onset of menopause (i.e., perimenopause) may be a critical period conferring increased susceptibility. However, the contribution of early ovarian decline to the neuroinflammatory processes associated with cerebrovascular dementia risks, particularly at the initial stages of pathology that may be more amenable to proactive intervention, is unknown. To better understand the influence of early ovarian failure on dementia-associated neuroinflammation we developed a model of perimenopausal cerebral amyloid angiopathy (CAA), an important contributor to dementia. For this, accelerated ovarian failure (AOF) was induced by 4-vinylcyclohexene diepoxide (VCD) treatment to isolate early-stage ovarian failure comparable to human perimenopause (termed "peri-AOF") in transgenic SWDI mice expressing human vasculotropic mutant amyloid beta (Aβ) precursor protein, that were also tested at an early stage of amyloidosis. We found that peri-AOF SWDI mice showed increased astrocyte activation accompanied by elevated Aβ in select regions of the hippocampus, a brain system involved in learning and memory that is severely impacted during dementia. However, although SWDI mice showed signs of increased hippocampal microglial activation and impaired cognitive function, this was not further affected by peri-AOF. In sum, these results suggest that elevated dysfunction of key elements of the neurovascular unit in select hippocampal regions characterizes the brain pathology of mice at early stages of both CAA and AOF. However, neurovascular unit pathology may not yet have passed a threshold that leads to further behavioral compromise at these early periods of cerebral amyloidosis and ovarian failure. These results are consistent with the hypothesis that the hormonal dysregulation associated with perimenopause onset represents a stage of emerging vulnerability to dementia-associated neuropathology, thus providing a selective window of opportunity for therapeutic intervention prior to the development of advanced pathology that has proven difficult to repair or reverse.
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Affiliation(s)
- Jimcy Platholi
- Weill Cornell Medicine, Feil Family Brain and Mind Research Institute, New York, NY, United States
- Anesthesiology Department, Weill Cornell Medicine, New York, NY, United States
| | - Roberta Marongiu
- Weill Cornell Medicine, Feil Family Brain and Mind Research Institute, New York, NY, United States
- Neurological Surgery Department, Weill Cornell Medicine, New York, NY, United States
- Genetic Medicine Department, Weill Cornell Medicine, New York, NY, United States
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD, United States
| | - Laibaik Park
- Weill Cornell Medicine, Feil Family Brain and Mind Research Institute, New York, NY, United States
| | - Fangmin Yu
- Weill Cornell Medicine, Feil Family Brain and Mind Research Institute, New York, NY, United States
| | - Garrett Sommer
- Weill Cornell Medicine, Feil Family Brain and Mind Research Institute, New York, NY, United States
| | - Rena Weinberger
- Weill Cornell Medicine, Feil Family Brain and Mind Research Institute, New York, NY, United States
| | - William Tower
- Neurological Surgery Department, Weill Cornell Medicine, New York, NY, United States
| | - Teresa A. Milner
- Weill Cornell Medicine, Feil Family Brain and Mind Research Institute, New York, NY, United States
- Harold and Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY, United States
| | - Michael J. Glass
- Weill Cornell Medicine, Feil Family Brain and Mind Research Institute, New York, NY, United States
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Lai YM, Chang YL. Age-related differences in associative memory recognition of Chinese characters and hippocampal subfield volumes. Biol Psychol 2023; 183:108657. [PMID: 37562576 DOI: 10.1016/j.biopsycho.2023.108657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 07/26/2023] [Accepted: 08/07/2023] [Indexed: 08/12/2023]
Abstract
Associative memory is a type of hippocampal-dependent episodic memory that declines with age. Studies have examined the neural substrates underlying associative memory and considered the hippocampus holistically; however, the association between associative memory decline and volumetric change in hippocampal subfields in the context of normal aging remains uncharacterized. Leveraging the distinct linguistic features of Chinese characters to evaluate distinct types of false recognition, we investigated age-related differences in associative recognition and hippocampal subfield volumes, as well as the relationship between behavioral performance and hippocampal morphometry in 25 younger adults and 32 older adults. The results showed an age-related associative memory deficit, which was exacerbated after a 30-min delay. Older adults showed higher susceptibility to false alarm errors with recombined and orthographically related foils compared to phonologically or semantically related ones. Moreover, we detected a disproportionately age-related, time-dependent increase in orthographic errors. Older adults exhibited smaller volumes in all hippocampal subfields when compared to younger adults, with a less pronounced effect observed in the CA2/3 subfield. Group-collapsed correlational analyses revealed associations between specific hippocampal subfields and associative memory but not item memory. Additionally, multi-subfield regions had prominent associations with delayed recognition. These findings underscore the significance of multiple hippocampal subfields in various hippocampal-dependent processes including associative memory, recollection-based retrieval, and pattern separation ability. Moreover, our observations of age-related difficulty in differentiating perceptually similar foils from targets provide a unique opportunity for examining the essential contribution of individual hippocampal subfields to the pattern separation process in mnemonic recognition.
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Affiliation(s)
- Ya-Mei Lai
- Department of Psychology, College of Science, National Taiwan University, Taipei, Taiwan; Department of Neurology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan; Clinical Psychology Center, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yu-Ling Chang
- Department of Psychology, College of Science, National Taiwan University, Taipei, Taiwan; Department of Neurology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan; Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan; Center for Artificial Intelligence and Advanced Robotics, National Taiwan University, Taipei, Taiwan.
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Dick AS, Ralph Y, Farrant K, Reeb-Sutherland B, Pruden S, Mattfeld AT. Volumetric development of hippocampal subfields and hippocampal white matter connectivity: Relationship with episodic memory. Dev Psychobiol 2022; 64:e22333. [PMID: 36426794 DOI: 10.1002/dev.22333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 08/22/2022] [Accepted: 09/02/2022] [Indexed: 01/27/2023]
Abstract
The hippocampus is a complex structure composed of distinct subfields. It has been central to understanding neural foundations of episodic memory. In the current cross-sectional study, using a large sample of 830, 3- to 21-year-olds from a unique, publicly available dataset we examined the following questions: (1) Is there elevated grey matter volume of the hippocampus and subfields in late compared to early development? (2) How does hippocampal volume compare with the rest of the cerebral cortex at different developmental stages? and (3) What is the relation between hippocampal volume and connectivity with episodic memory performance? We found hippocampal subfield volumes exhibited a nonlinear relation with age and showed a lag in volumetric change with age when compared to adjacent cortical regions (e.g., entorhinal cortex). We also observed a significant reduction in cortical volume across older cohorts, while hippocampal volume showed the opposite pattern. In addition to age-related differences in gray matter volume, dentate gyrus/cornu ammonis 3 volume was significantly related to episodic memory. We did not, however, find any associations with episodic memory performance and connectivity through the uncinate fasciculus, fornix, or cingulum. The results are discussed in the context of current research and theories of hippocampal development and its relation to episodic memory.
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Affiliation(s)
- Anthony Steven Dick
- Department of Psychology, Florida International University, Miami, Florida, USA
| | - Yvonne Ralph
- Department of Psychology, Florida International University, Miami, Florida, USA
| | - Kristafor Farrant
- Department of Psychology, Florida International University, Miami, Florida, USA
| | | | - Shannon Pruden
- Department of Psychology, Florida International University, Miami, Florida, USA
| | - Aaron T Mattfeld
- Department of Psychology, Florida International University, Miami, Florida, USA
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Milner TA, Chen RX, Welington D, Rubin BR, Contoreggi NH, Johnson MA, Mazid S, Marques-Lopes J, Marongiu R, Glass MJ. Angiotensin II differentially affects hippocampal glial inflammatory markers in young adult male and female mice. Learn Mem 2022; 29:265-273. [PMID: 36206386 PMCID: PMC9488028 DOI: 10.1101/lm.053507.121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 05/03/2022] [Indexed: 12/16/2022]
Abstract
Hypertension is a risk factor for neurodegenerative disorders involving inflammation and inflammatory cytokine-producing brain cells (microglia and astrocytes) in the hippocampus and medial prefrontal cortex (mPFC). Here we investigated the effect of slow-pressor angiotensin II (AngII) on gliosis in the hippocampus and mPFC of young adult (2-mo-old) male and female mice. In males, AngII induced hypertension, and this resulted in an increase in the density of the astrocyte marker glial fibrillary acidic protein (GFAP) in the subgranular hilus and a decrease in the density of the microglial marker ionized calcium binding adapter molecule (Iba-1) in the CA1 region. Females infused with AngII did not show hypertension but, significantly, showed alterations in hippocampal glial activation. Compared with vehicle, AngII-infused female mice had an increased density of Iba-1 in the dentate gyrus and CA2/3a region. Like males, females infused with AngII exhibited decreased Iba-1 in the CA1 region. Neither male nor female mice showed differences in GFAP or Iba-1 in the mPFC following AngII infusion. These results demonstrate that the hippocampus is particularly vulnerable to AngII in young adulthood. Differences in gonadal hormones or the sensitivity to AngII hypertension may account for divergences in GFAP and Iba-1 in males and females.
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Affiliation(s)
- Teresa A Milner
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065, USA
- Harold and Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, New York, New York 10065, USA
| | - Ryan X Chen
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065, USA
| | - Diedreanna Welington
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065, USA
| | - Batsheva R Rubin
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065, USA
| | - Natalina H Contoreggi
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065, USA
| | - Megan A Johnson
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065, USA
| | - Sanoara Mazid
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065, USA
| | - Jose Marques-Lopes
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065, USA
| | - Roberta Marongiu
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065, USA
- Neurological Surgery Department, Weill Cornell Medicine, New York, New York 10065, USA
| | - Michael J Glass
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065, USA
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Olsen LK, Moore RJ, Bechmann NA, Ethridge VT, Gargas NM, Cunningham SD, Kuang Z, Whicker JK, Rohan JG, Hatcher-Solis CN. Vagus nerve stimulation-induced cognitive enhancement: Hippocampal neuroplasticity in healthy male rats. Brain Stimul 2022; 15:1101-1110. [PMID: 35970317 DOI: 10.1016/j.brs.2022.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/29/2022] [Accepted: 08/03/2022] [Indexed: 11/02/2022] Open
Abstract
BACKGROUND Vagus nerve stimulation (VNS) improves cognition in humans and rodents, but the effects of a single session of VNS on performance and plasticity are not well understood. OBJECTIVE Behavioral performance and hippocampal (HC) electrophysiology/neurotrophin expression were measured in healthy adult rats after VNS paired training to investigate changes in cognition and synaptic plasticity. METHODS Platinum/iridium electrodes were surgically implanted around the left cervical branch of the VN of anesthetized male Sprague-Dawley rats (N = 47). VNS (100 μs biphasic pulses, 30 Hz, 0.8 mA) paired Novel Object Recognition (NOR)/Passive Avoidance Task (PAT) were assessed 24 h after training and post-mortem tissue was collected 48 h after VNS (N = 28). Electrophysiology recordings were collected using a microelectrode array system to assess functional effects on HC slices 90 min after VNS (N = 19). Sham received the same treatment without VNS and experimenters were blinded. RESULTS Stimulated rats exhibited improved performance in NOR (p < 0.05, n = 12) and PAT (p < 0.05, n = 14). VNS enhanced long-term potentiation (p < 0.05, n = 7-12), and spontaneous spike amplitude (p < 0.05, n = 7-12) and frequency (p < 0.05, n = 7-12) in the CA1. Immunohistochemical analysis found increased brain-derived neurotrophic factor expression in the CA1 (p < 0.05, n = 8-9) and CA2 (p < 0.01, n = 7-8). CONCLUSION These findings suggest that our VNS parameters promote synaptic plasticity and target the CA1, which may mediate the positive cognitive effects of VNS. This study significantly contributes to a better understanding of VNS mediated HC synaptic plasticity, which may improve clinical utilization of VNS for cognitive enhancement.
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Affiliation(s)
- Laura K Olsen
- Cognitive Neuroscience, 711th HPW, AFRL, Wright-Patterson AFB, OH, USA; Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Raquel J Moore
- Cognitive Neuroscience, 711th HPW, AFRL, Wright-Patterson AFB, OH, USA; Infoscitex, Inc., Dayton, OH, USA
| | - Naomi A Bechmann
- Cognitive Neuroscience, 711th HPW, AFRL, Wright-Patterson AFB, OH, USA; Infoscitex, Inc., Dayton, OH, USA
| | - Victoria T Ethridge
- Naval Medical Research Unit Dayton, Wright-Patterson AFB, OH, USA; Odyssey Systems Consulting Group, Wakefield, MA, USA
| | - Nathan M Gargas
- Naval Medical Research Unit Dayton, Wright-Patterson AFB, OH, USA; Odyssey Systems Consulting Group, Wakefield, MA, USA
| | - Sylvia D Cunningham
- Cognitive Neuroscience, 711th HPW, AFRL, Wright-Patterson AFB, OH, USA; Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Zhanpeng Kuang
- Cognitive Neuroscience, 711th HPW, AFRL, Wright-Patterson AFB, OH, USA
| | - Joshua K Whicker
- Cognitive Neuroscience, 711th HPW, AFRL, Wright-Patterson AFB, OH, USA
| | - Joyce G Rohan
- Naval Medical Research Unit Dayton, Wright-Patterson AFB, OH, USA
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He H, Boehringer R, Huang AJY, Overton ETN, Polygalov D, Okanoya K, McHugh TJ. CA2 inhibition reduces the precision of hippocampal assembly reactivation. Neuron 2021; 109:3674-3687.e7. [PMID: 34555316 DOI: 10.1016/j.neuron.2021.08.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 07/02/2021] [Accepted: 08/27/2021] [Indexed: 12/29/2022]
Abstract
The structured reactivation of hippocampal neuronal ensembles during fast synchronous oscillatory events, termed sharp-wave ripples (SWRs), has been suggested to play a crucial role in the storage and use of memory. Activity in both the CA2 and CA3 subregions can precede this population activity in CA1, and chronic inhibition of either region alters SWR oscillations. However, the precise contribution of CA2 to the oscillation, as well as to the reactivation of CA1 neurons within it, remains unclear. Here, we employ chemogenetics to transiently silence CA2 pyramidal cells in mice, and we observe that although SWRs still occur, the reactivation of CA1 pyramidal cell ensembles within the events lose both temporal and informational precision. These observations suggest that CA2 activity contributes to the fidelity of experience-dependent hippocampal replay.
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Affiliation(s)
- Hongshen He
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan; Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Roman Boehringer
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | - Arthur J Y Huang
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | - Eric T N Overton
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | - Denis Polygalov
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | - Kazuo Okanoya
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan; Cognition and Behavior Joint Laboratory, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | - Thomas J McHugh
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan; Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
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Synaptic Reshaping and Neuronal Outcomes in the Temporal Lobe Epilepsy. Int J Mol Sci 2021; 22:ijms22083860. [PMID: 33917911 PMCID: PMC8068229 DOI: 10.3390/ijms22083860] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/02/2021] [Accepted: 04/04/2021] [Indexed: 12/11/2022] Open
Abstract
Temporal lobe epilepsy (TLE) is one of the most common types of focal epilepsy, characterized by recurrent spontaneous seizures originating in the temporal lobe(s), with mesial TLE (mTLE) as the worst form of TLE, often associated with hippocampal sclerosis. Abnormal epileptiform discharges are the result, among others, of altered cell-to-cell communication in both chemical and electrical transmissions. Current knowledge about the neurobiology of TLE in human patients emerges from pathological studies of biopsy specimens isolated from the epileptogenic zone or, in a few more recent investigations, from living subjects using positron emission tomography (PET). To overcome limitations related to the use of human tissue, animal models are of great help as they allow the selection of homogeneous samples still presenting a more various scenario of the epileptic syndrome, the presence of a comparable control group, and the availability of a greater amount of tissue for in vitro/ex vivo investigations. This review provides an overview of the structural and functional alterations of synaptic connections in the brain of TLE/mTLE patients and animal models.
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Lehr AB, Kumar A, Tetzlaff C, Hafting T, Fyhn M, Stöber TM. CA2 beyond social memory: Evidence for a fundamental role in hippocampal information processing. Neurosci Biobehav Rev 2021; 126:398-412. [PMID: 33775693 DOI: 10.1016/j.neubiorev.2021.03.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/16/2021] [Accepted: 03/18/2021] [Indexed: 01/16/2023]
Abstract
Hippocampal region CA2 has received increased attention due to its importance in social recognition memory. While its specific function remains to be identified, there are indications that CA2 plays a major role in a variety of situations, widely extending beyond social memory. In this targeted review, we highlight lines of research which have begun to converge on a more fundamental role for CA2 in hippocampus-dependent memory processing. We discuss recent proposals that speak to the computations CA2 may perform within the hippocampal circuit.
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Affiliation(s)
- Andrew B Lehr
- Department of Computational Neuroscience, University of Göttingen, Germany; Bernstein Center for Computational Neuroscience, University of Göttingen, Germany; Department of Computational Physiology, Simula Research Laboratory, Lysaker, Norway; Centre for Integrative Neuroplasticity, University of Oslo, Norway.
| | - Arvind Kumar
- Department of Computational Science and Technology, KTH Royal Institute of Technology, Sweden
| | - Christian Tetzlaff
- Department of Computational Neuroscience, University of Göttingen, Germany; Bernstein Center for Computational Neuroscience, University of Göttingen, Germany
| | - Torkel Hafting
- Centre for Integrative Neuroplasticity, University of Oslo, Norway; Institute of Basic Medical Sciences, University of Oslo, Norway
| | - Marianne Fyhn
- Centre for Integrative Neuroplasticity, University of Oslo, Norway; Department of Biosciences, University of Oslo, Norway
| | - Tristan M Stöber
- Department of Computational Physiology, Simula Research Laboratory, Lysaker, Norway; Centre for Integrative Neuroplasticity, University of Oslo, Norway; Department of Informatics, University of Oslo, Norway.
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Homayouni R, Yu Q, Ramesh S, Tang L, Daugherty AM, Ofen N. Test-retest reliability of hippocampal subfield volumes in a developmental sample: Implications for longitudinal developmental studies. J Neurosci Res 2021; 99:2327-2339. [PMID: 33751637 DOI: 10.1002/jnr.24831] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/04/2021] [Indexed: 12/21/2022]
Abstract
The hippocampus (Hc) is composed of cytoarchitectonically distinct subfields: dentate gyrus (DG), cornu ammonis sectors 1-3 (CA1-3), and subiculum. Limited evidence suggests differential maturation rates across the Hc subfields. While longitudinal studies are essential in demonstrating differential development of Hc subfields, a prerequisite for interpreting meaningful longitudinal effects is establishing test-retest consistency of Hc subfield volumes measured in vivo over time. Here, we examined test-retest consistency of Hc subfield volumes measured from structural MR images in two independent developmental samples. Sample One (n = 28, ages 7-20 years, M = 12.64, SD = 3.35) and Sample Two (n = 28, ages 7-17 years, M = 11.72, SD = 2.88) underwent MRI twice with a 1-month and a 2-year delay, respectively. High-resolution PD-TSE-T2 -weighted MR images (0.4 × 0.4 × 2 mm3 ) were collected and manually traced using a longitudinal manual demarcation protocol. In both samples, we found excellent consistency of Hc subfield volumes between the two visits, assessed by two-way mixed intraclass correlation (ICC (3) single measures ≥ 0.87), and no difference between children and adolescents. The results further indicated that discrepancies between repeated measures were not related to Hc subfield volumes, or visit number. In addition to high consistency, with the applied longitudinal protocol, we detected significant variability in Hc subfield volume changes over the 2-year delay, implying high sensitivity of the method in detecting individual differences. Establishing unbiased, high longitudinal consistency of Hc subfield volume measurements optimizes statistical power of a hypothesis test and reduces standard error of the estimate, together improving external validity of the measures in constructing theoretical models of memory development.
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Affiliation(s)
- Roya Homayouni
- Institute of Gerontology, Wayne State University, Detroit, MI, USA.,Department of Psychology, Wayne State University, Detroit, MI, USA
| | - Qijing Yu
- Institute of Gerontology, Wayne State University, Detroit, MI, USA.,Department of Psychology, Wayne State University, Detroit, MI, USA
| | - Sruthi Ramesh
- Institute of Gerontology, Wayne State University, Detroit, MI, USA
| | - Lingfei Tang
- Institute of Gerontology, Wayne State University, Detroit, MI, USA
| | - Ana M Daugherty
- Institute of Gerontology, Wayne State University, Detroit, MI, USA.,Department of Psychology, Wayne State University, Detroit, MI, USA.,Department of Psychiatry and Behavioral Neurosciences, School of Medicine, Wayne State University, Detroit, MI, USA
| | - Noa Ofen
- Institute of Gerontology, Wayne State University, Detroit, MI, USA.,Department of Psychology, Wayne State University, Detroit, MI, USA.,Merrill Palmer Skillman Institute, Wayne State University, Detroit, MI, USA
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12
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Laham BJ, Diethorn EJ, Gould E. Newborn mice form lasting CA2-dependent memories of their mothers. Cell Rep 2021; 34:108668. [PMID: 33503421 PMCID: PMC7985754 DOI: 10.1016/j.celrep.2020.108668] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 10/26/2020] [Accepted: 12/29/2020] [Indexed: 01/02/2023] Open
Abstract
Some of the most enduring social connections begin when infants first recognize their caregivers, memories that form the basis of many family relationships. It remains unknown whether these early social memories persist into adulthood in mice and, if so, which brain regions support them. Here we show that mice form memories of their mother within days after birth and that these memories persist into adulthood. Pups display greater interest in the mother than in an unfamiliar dam before weaning, after which this preference reverses. Inhibition of CA2 neurons in the pup temporarily blocks the ability to discriminate between the mother and an unfamiliar dam, whereas doing so in adulthood prevents the formation of short-term memories about conspecifics, as well as social discrimination related to long-term memories of the mother. These results suggest that the CA2 supports memories of the mother during infancy and adulthood with a developmental switch in social preference.
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Affiliation(s)
- Blake J Laham
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Emma J Diethorn
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Elizabeth Gould
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA.
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13
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Yamamoto N, Marks WD, Kitamura T. Cell-Type-Specific Optogenetic Techniques Reveal Neural Circuits Crucial for Episodic Memories. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1293:429-447. [PMID: 33398831 PMCID: PMC8612024 DOI: 10.1007/978-981-15-8763-4_28] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The formation and maintenance of episodic memories are important for our daily life. Accumulating evidence from extensive studies with pharmacological, electrophysiological, and molecular biological approaches has shown that both entorhinal cortex (EC) and hippocampus (HPC) are crucial for the formation and recall of episodic memory. However, to further understand the neural mechanisms of episodic memory processes in the EC-HPC network, cell-type-specific manipulation of neural activity with high temporal resolution during memory process has become necessary. Recently, the technological innovation of optogenetics combined with pharmacological, molecular biological, and electrophysiological approaches has significantly advanced our understanding of the circuit mechanisms for learning and memory. Optogenetic techniques with transgenic mice and/or viral vectors enable us to manipulate the neural activity of specific cell populations as well as specific neural projections with millisecond-scale temporal control during animal behavior. Integrating optogenetics with drug-regulatable activity-dependent gene expression systems has identified memory engram cells, which are a subpopulation of cells that encode a specific episode. Finally, millisecond pulse stimulation of neural activity by optogenetics has further achieved (a) identification of synaptic connectivity between targeted pairs of neural populations, (b) cell-type-specific single-unit electrophysiological recordings, and (c) artificial induction and modification of synaptic plasticity in targeted synapses. In this chapter, we summarize technological and conceptual advancements in the field of neurobiology of learning and memory as revealed by optogenetic approaches in the rodent EC-HPC network for episodic memories.
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Affiliation(s)
- Naoki Yamamoto
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - William D Marks
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Takashi Kitamura
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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14
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Pillay S, Bhagwandin A, Bertelsen MF, Patzke N, Engler G, Engel AK, Manger PR. The hippocampal formation of two carnivore species: The feliform banded mongoose and the caniform domestic ferret. J Comp Neurol 2020; 529:8-27. [PMID: 33016331 DOI: 10.1002/cne.25047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/29/2020] [Accepted: 09/30/2020] [Indexed: 02/03/2023]
Abstract
Employing cyto-, myelo-, and chemoarchitectural staining techniques, we analyzed the structure of the hippocampal formation in the banded mongoose and domestic ferret, species belonging to the two carnivoran superfamilies, which have had independent evolutionary trajectories for the past 55 million years. Our observations indicate that, despite the time since sharing a last common ancestor, these species show extensive similarities. The four major portions of the hippocampal formation (cornu Ammonis, dentate gyrus, subicular complex, and entorhinal cortex) were readily observed, contained the same internal subdivisions, and maintained the topological relationships of these subdivisions that could be considered typically mammalian. In addition, adult hippocampal neurogenesis was observed in both species, occurring at a rate similar to that observed in other mammals. Despite the overall similarities, several differences to each other, and to other mammalian species, were observed. We could not find evidence for the presence of the CA2 and CA4 fields of the cornu Ammonis region. In the banded mongoose the dentate gyrus appears to be comprised of up to seven lamina, through the sublamination of the molecular and granule cell layers, which is not observed in the domestic ferret. In addition, numerous subtle variations in chemoarchitecture between the two species were observed. These differences may contribute to an overall variation in the functionality of the hippocampal formation between the species, and in comparison to other mammalian species. These similarities and variations are important to understanding to what extent phylogenetic affinities and constraints affect potential adaptive evolutionary plasticity of the hippocampal formation.
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Affiliation(s)
- Sashrika Pillay
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Mads F Bertelsen
- Centre for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg, Denmark
| | - Nina Patzke
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Gerhard Engler
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andreas K Engel
- Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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15
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Abstract
Contemporary brain research seeks to understand how cognition is reducible to neural activity. Crucially, much of this effort is guided by a scientific paradigm that views neural activity as essentially driven by external stimuli. In contrast, recent perspectives argue that this paradigm is by itself inadequate and that understanding patterns of activity intrinsic to the brain is needed to explain cognition. Yet, despite this critique, the stimulus-driven paradigm still dominates-possibly because a convincing alternative has not been clear. Here, we review a series of findings suggesting such an alternative. These findings indicate that neural activity in the hippocampus occurs in one of three brain states that have radically different anatomical, physiological, representational, and behavioral correlates, together implying different functional roles in cognition. This three-state framework also indicates that neural representations in the hippocampus follow a surprising pattern of organization at the timescale of ∼1 s or longer. Lastly, beyond the hippocampus, recent breakthroughs indicate three parallel states in the cortex, suggesting shared principles and brain-wide organization of intrinsic neural activity.
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Affiliation(s)
- Kenneth Kay
- Howard Hughes Medical Institute, Kavli Institute for Fundamental Neuroscience, Department of Physiology, University of California San Francisco, San Francisco, California
| | - Loren M Frank
- Howard Hughes Medical Institute, Kavli Institute for Fundamental Neuroscience, Department of Physiology, University of California San Francisco, San Francisco, California
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16
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Fernandez-Lamo I, Gomez-Dominguez D, Sanchez-Aguilera A, Oliva A, Morales AV, Valero M, Cid E, Berenyi A, Menendez de la Prida L. Proximodistal Organization of the CA2 Hippocampal Area. Cell Rep 2020; 26:1734-1746.e6. [PMID: 30759386 PMCID: PMC6389459 DOI: 10.1016/j.celrep.2019.01.060] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 10/25/2018] [Accepted: 01/15/2019] [Indexed: 12/13/2022] Open
Abstract
The proximodistal axis is considered a major organizational principle of the hippocampus. At the interface between the hippocampus and other brain structures, CA2 apparently breaks this rule. The region is involved in social, temporal, and contextual memory function, but mechanisms remain elusive. Here, we reveal cell-type heterogeneity and a characteristic expression gradient of the transcription factor Sox5 within CA2 in the rat. Using intracellular and extracellular recordings followed by neurochemical identification of single cells, we find marked proximodistal trends of synaptic activity, subthreshold membrane potentials, and phase-locked firing coupled to theta and gamma oscillations. Phase-shifting membrane potentials and opposite proximodistal correlations with theta sinks and sources at different layers support influences from different current generators. CA2 oscillatory activity and place coding of rats running in a linear maze reflect proximodistal state-dependent trends. We suggest that the structure and function of CA2 are distributed along the proximodistal hippocampal axis. The CA2 region is organized around the limit of the mossy fibers Heterogeneous pyramidal cell types populate the proximal and distal CA2 region Responses to intra- and extra-hippocampal inputs segregate along this axis CA2 oscillatory activity and spatial coding change proximodistally
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Affiliation(s)
| | | | | | - Azahara Oliva
- Department of Neuroscience, Zuckerman and Kavli Institutes, Columbia University, 3227 Broadway, New York, NY 10027, USA
| | | | - Manuel Valero
- Instituto Cajal, CSIC, Ave Doctor Arce 37, Madrid 28002, Spain
| | - Elena Cid
- Instituto Cajal, CSIC, Ave Doctor Arce 37, Madrid 28002, Spain
| | - Antal Berenyi
- MTA-SZTE "Momentum" Oscillatory Neuronal Networks Research Group, Interdisciplinary Excellence Centre, Department of Physiology, University of Szeged, Szeged 6720, Hungary
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17
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de la Prida LM. Potential factors influencing replay across CA1 during sharp-wave ripples. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190236. [PMID: 32248778 DOI: 10.1098/rstb.2019.0236] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Sharp-wave ripples are complex neurophysiological events recorded along the trisynaptic hippocampal circuit (i.e. from CA3 to CA1 and the subiculum) during slow-wave sleep and awake states. They arise locally but scale brain-wide to the hippocampal target regions at cortical and subcortical structures. During these events, neuronal firing sequences are replayed retrospectively or prospectively and in the forward or reverse order as defined by experience. They could reflect either pre-configured firing sequences, learned sequences or an option space to inform subsequent decisions. How can different sequences arise during sharp-wave ripples? Emerging data suggest the hippocampal circuit is organized in different loops across the proximal (close to dentate gyrus) and distal (close to entorhinal cortex) axis. These data also disclose a so-far neglected laminar organization of the hippocampal output during sharp-wave events. Here, I discuss whether by incorporating cell-type-specific mechanisms converging on deep and superficial CA1 sublayers along the proximodistal axis, some novel factors influencing the organization of hippocampal sequences could be unveiled. This article is part of the Theo Murphy meeting issue 'Memory reactivation: replaying events past, present and future'.
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18
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Zhang C, Huo S, Fan Y, Gao Y, Yang Y, Sun D. Autophagy May Be Involved in Fluoride-Induced Learning Impairment in Rats. Biol Trace Elem Res 2020; 193:502-507. [PMID: 31111310 DOI: 10.1007/s12011-019-01735-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 01/22/2019] [Indexed: 12/30/2022]
Abstract
Fluoride can induce neurotoxicity, but the mechanism is not clear. In this study, we explored the role of autophagy in F--induced neurotoxicity of Wistar rats. Eighty Wistar rats were randomly divided into four groups: the control group (distilled water containing less than 0.1 mg/L F-) and three NaF-treated groups (F- was respectively administered at 25, 50, and 100 mg/L orally via drinking water). The water maze experiment showed that NaF exposure impaired the learning capabilities of the rats. When compared with the control group, the mean escape latency of the rats in the 100 mg/L F- group was much longer (P < 0.05). Immunohistochemical analysis showed that NaF exposure induced autophagy, as shown by the significant increase of Beclin-1 expression in the hippocampal CA1 region and DG region. Transmission electron microscopy was used to observe the ultrastructural changes of hippocampal neurons. With the increase of F- concentration, the ultrastructural abnormalities of hippocampal neurons increased. These results indicate that fluoride can impair the learning ability of rats, which may be related to the induction of autophagy in rat hippocampal neurons.
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Affiliation(s)
- Chengzhi Zhang
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Harbin, 150081, China
| | - Simeng Huo
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Harbin, 150081, China
| | - Yumei Fan
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Harbin, 150081, China
| | - Yanhui Gao
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Harbin, 150081, China
| | - Yanmei Yang
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Harbin, 150081, China
| | - Dianjun Sun
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health, Harbin, 150081, China.
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19
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Excitation/inhibition imbalance and impaired neurogenesis in neurodevelopmental and neurodegenerative disorders. Rev Neurosci 2019; 30:807-820. [DOI: 10.1515/revneuro-2019-0014] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 04/05/2019] [Indexed: 12/31/2022]
Abstract
AbstractThe excitation/inhibition (E/I) balance controls the synaptic inputs to prevent the inappropriate responses of neurons to input strength, and is required to restore the initial pattern of network activity. Various neurotransmitters affect synaptic plasticity within neural networks via the modulation of neuronal E/I balance in the developing and adult brain. Less is known about the role of E/I balance in the control of the development of the neural stem and progenitor cells in the course of neurogenesis and gliogenesis. Recent findings suggest that neural stem and progenitor cells appear to be the target for the action of GABA within the neurogenic or oligovascular niches. The same might be true for the role of neuropeptides (i.e. oxytocin) in neurogenic niches. This review covers current understanding of the role of E/I balance in the regulation of neuroplasticity associated with social behavior in normal brain, and in neurodevelopmental and neurodegenerative diseases. Further studies are required to decipher the GABA-mediated regulation of postnatal neurogenesis and synaptic integration of newly-born neurons as a potential target for the treatment of brain diseases.
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20
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Chang J, Yu R. Hippocampal connectivity in the aftermath of acute social stress. Neurobiol Stress 2019; 11:100195. [PMID: 31832509 PMCID: PMC6889252 DOI: 10.1016/j.ynstr.2019.100195] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/06/2019] [Accepted: 09/13/2019] [Indexed: 12/12/2022] Open
Abstract
The hippocampus is a core brain region that responds to stress. Previous studies have found a dysconnectivity between hippocampus and other brain regions under acute and chronic stress. However, whether and how acute social stress influences the directed connectivity patterns from and to the hippocampus remains unclear. In this study, using a within-subject design and Granger causal analysis (GCA), we investigated the alterations of resting state effective connectivity from and to hippocampal subregions after an acute social stressor (the Trier Social Stress Test). Participants were engaged in stress and control conditions spaced approximately one month apart. Our findings showed that stress altered the information flows in the thalamus-hippocampus-insula/midbrain circuit. The changes in this circuit could also predict with high accuracy the stress and control conditions at the subject level. These hippocampus-related brain networks have been documented to be involved in emotional information processing and storage, as well as habitual responses. We speculate that alterations of the effective connectivity between these brain regions may be associated with the registering and encoding of threatening stimuli under stress. Our investigation of hippocampal functional connectivity at a subregional level may help elucidate the functional neurobiology of stress-related psychiatric disorders.
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Affiliation(s)
- Jingjing Chang
- Guangdong Key Laboratory of Mental Health and Cognitive Science, Center for Studies of Psychological Application, School of Psychology, South China Normal University, Guangzhou, China
| | - Rongjun Yu
- Department of Psychology, National University of Singapore, Singapore
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21
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Tzakis N, Holahan MR. Social Memory and the Role of the Hippocampal CA2 Region. Front Behav Neurosci 2019; 13:233. [PMID: 31632251 PMCID: PMC6779725 DOI: 10.3389/fnbeh.2019.00233] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 09/17/2019] [Indexed: 01/02/2023] Open
Abstract
The CA2 region of the hippocampus is a somewhat obscure area lacking in an understanding of its form and function. Until recently, the CA2 has been thought of as merely an extension of the CA3, with some referring to it as the CA3a region. Recent investigations into this area have not only delineated the CA2, but also defined it as a region distinct from both CA1 and CA3, with a unique set of cortical inputs and outputs and contributions to cognitive processes. One such process that has been shown to depend on the CA2 is the ability to recognize a novel or familiar conspecific, known as social recognition memory. Here, we review these findings and discuss the parallels between CA2 dysfunction and social impairments.
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Affiliation(s)
- Nikolaos Tzakis
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
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22
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Reduced perineuronal net expression in Fmr1 KO mice auditory cortex and amygdala is linked to impaired fear-associated memory. Neurobiol Learn Mem 2019; 164:107042. [PMID: 31326533 DOI: 10.1016/j.nlm.2019.107042] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 06/20/2019] [Accepted: 07/10/2019] [Indexed: 02/06/2023]
Abstract
Fragile X Syndrome (FXS) is a leading cause of heritable intellectual disability and autism. Humans with FXS show anxiety, sensory hypersensitivity and impaired learning. The mechanisms of learning impairments can be studied in the mouse model of FXS, the Fmr1 KO mouse, using tone-associated fear memory paradigms. Our previous study reported impaired development of parvalbumin (PV) positive interneurons and perineuronal nets (PNN) in the auditory cortex of Fmr1 KO mice. A recent study suggested PNN dynamics in the auditory cortex following tone-shock association is necessary for fear expression. Together these data suggest that abnormal PNN regulation may underlie tone-fear association learning deficits in Fmr1 KO mice. We tested this hypothesis by quantifying PV and PNN expression in the amygdala, hippocampus and auditory cortex of Fmr1 KO mice following fear conditioning. We found impaired tone-associated memory formation in Fmr1 KO mice. This was paralleled by impaired learning-associated regulation of PNNs in the superficial layers of auditory cortex in Fmr1 KO mice. PV cell density decreased in the auditory cortex in response to fear conditioning in both WT and Fmr1 KO mice. Learning-induced increase of PV expression in the CA3 hippocampus was only observed in WT mice. We also found reduced PNN density in the amygdala and auditory cortex of Fmr1 KO mice in all conditions, as well as reduced PNN intensity in CA2 hippocampus. There was a positive correlation between tone-associated memory and PNN density in the amygdala and auditory cortex, consistent with a tone-association deficit. Altogether our studies suggest a link between impaired PV and PNN regulation within specific regions of the fear conditioning circuit and impaired tone memory formation in Fmr1 KO mice.
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23
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Involvement of hippocampal subfields and anterior-posterior subregions in encoding and retrieval of item, spatial, and associative memories: Longitudinal versus transverse axis. Neuroimage 2019; 191:568-586. [DOI: 10.1016/j.neuroimage.2019.01.061] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 01/17/2019] [Accepted: 01/22/2019] [Indexed: 11/18/2022] Open
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24
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Do multiple system atrophy and Parkinson's disease show distinct patterns of volumetric alterations across hippocampal subfields? An exploratory study. Eur Radiol 2019; 29:4948-4956. [PMID: 30796577 DOI: 10.1007/s00330-019-06043-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 12/25/2018] [Accepted: 01/24/2019] [Indexed: 12/21/2022]
Abstract
OBJECTIVES To investigate the volumetric alterations of hippocampal subfields and identify which subfields contribute to mild cognitive impairment (MCI) in multiple system atrophy (MSA) and Parkinson's disease (PD). METHODS Thirty MSA-MCI, 26 PD-MCI, and 30 healthy controls were administered cognitive assessment, along with hippocampal segmentation using FreeSurfer 6.0 after a 3-T MRI scan. Regression analyses were performed between the volumes of hippocampal subfields and cognitive variables. RESULTS Compared with healthy controls, the volume of the hippocampal fissure was enlarged in PD-MCI patients, while left Cornu Ammonis (CA2-CA3), bilateral molecular layer, bilateral hippocampus-amygdala transition area, right subiculum, right CA1, right presubiculum, right parasubiculum, and bilateral whole hippocampus were reduced in the MSA-MCI group. Moreover, volumetric reductions of the bilateral hippocampal tail, bilateral CA1, bilateral presubiculum, bilateral molecular layer, left CA2-CA3, left hippocampus-amygdala transition area, right parasubiculum, and bilateral whole hippocampus were found in MSA-MCI relative to the PD-MCI group. The volumes of the left CA2-CA3 (B = - 11.34, p = 0.006) and left parasubiculum (B = 4.63, p = 0.01) were respectively correlated with language and abstraction functions. The volumes of the left fimbria (B = 6.99, p = 0.002) and left hippocampus-amygdala transition area (B = 2.28, p = 0.009) were correlated with visuospatial/executive function. CONCLUSIONS The MSA-MCI patients showed more widespread impairment of hippocampal subfields compared with the PD-MCI group, involving trisynaptic loop and amygdala-hippocampus interactions. The alteration of CA, hippocampus-amygdala transition area, and fimbria still requires further comparison between the two patient groups. KEY POINTS • The atrophy patterns of hippocampal subfields differed between MSA and PD patients. • MSA has widespread change in trisynaptic loop and amygdala-hippocampus interactions. • The atrophy patterns may help to understand the differences of cognitive impairment in MSA and PD.
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25
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Imam A, Bhagwandin A, Ajao MS, Ihunwo AO, Manger PR. The brain of the tree pangolin (Manis tricuspis). IV. The hippocampal formation. J Comp Neurol 2019; 527:2393-2412. [PMID: 30592043 DOI: 10.1002/cne.24620] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 12/20/2018] [Accepted: 12/20/2018] [Indexed: 01/06/2023]
Abstract
Employing a range of standard and immunohistochemical stains we provide a description of the hippocampal formation in the brain of the tree pangolin. For the most part, the architecture, chemical neuroanatomy, and topological relationships of the component parts of the hippocampal formation of the tree pangolin were consistent with that observed in other mammalian species. Within the hippocampus proper fields CA1, 3, and 4 could be identified with certainty, while CA2 was tentatively identified as a small transitional zone between the CA1 and CA3 fields. Within the dentate gyrus evidence for adult hippocampal neurogenesis at a rate comparable to other mammals was observed. The subicular complex and entorhinal cortex also exhibited divisions typically observed in other mammalian species. In contrast to many other mammals, an architecturally and neurochemically distinct CA4 field was observed, supporting Lorente de Nó's proposed CA4 field, at least in some mammalian species. In addition, up to seven laminae were evident in the dentate gyrus. Calretinin immunostaining revealed the three sublamina of the molecular layer, while immunostaining for vesicular glutamate transporter 2 and neurofilament H indicate that the granule cell layer was composed of two sublamina. The similarities and differences observed in the tree pangolin indicate that the hippocampal formation is an anatomically and neurochemically conserved neural unit in mammalian evolution, but minor changes may relate to specific life history features and habits of species.
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Affiliation(s)
- Aminu Imam
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa.,Department of Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Moyosore S Ajao
- Department of Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Amadi O Ihunwo
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
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26
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Das T, Hwang JJ, Poston KL. Episodic recognition memory and the hippocampus in Parkinson's disease: A review. Cortex 2018; 113:191-209. [PMID: 30660957 DOI: 10.1016/j.cortex.2018.11.021] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 10/02/2018] [Accepted: 11/15/2018] [Indexed: 01/09/2023]
Abstract
Parkinson's disease is a progressive neurodegenerative disorder of aging. The hallmark pathophysiology includes the development of neuronal Lewy bodies in the substantia nigra of the midbrain with subsequent loss of dopaminergic neurons. These neuronal losses lead to the characteristic motor symptoms of bradykinesia, rigidity, and rest tremor. In addition to these cardinal motor symptoms patients with PD experience a wide range of non-motor symptoms, the most important being cognitive impairments that in many circumstances lead to dementia. People with PD experience a wide range of cognitive impairments; in this review we will focus on memory impairment in PD and specifically episodic memory, which are memories of day-to-day events of life. Importantly, these memory impairments severely impact the lives of patients and caregivers alike. Traditionally episodic memory is considered to be markedly dependent on the hippocampus; therefore, it is important to understand the exact nature of PD episodic memory deficits in relation to hippocampal function and dysfunction. In this review, we discuss an aspect of episodic memory called recognition memory and its subcomponents called recollection and familiarity. Recognition memory is believed to be impaired in PD; thus, we discuss what aspects of the hippocampus are expected to be deficient in function as they relate to these recognition memory impairments. In addition to the hippocampus as a whole, we will discuss the role of hippocampal subfields in recognition memory impairments.
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Affiliation(s)
- Tanusree Das
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA.
| | - Jaclyn J Hwang
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA; Department of Neuroscience, University of Pittsburgh, USA.
| | - Kathleen L Poston
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA; Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA.
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27
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Chiang MC, Huang AJ, Wintzer ME, Ohshima T, McHugh TJ. A role for CA3 in social recognition memory. Behav Brain Res 2018; 354:22-30. [DOI: 10.1016/j.bbr.2018.01.019] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/15/2018] [Accepted: 01/17/2018] [Indexed: 11/15/2022]
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28
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Tirko NN, Eyring KW, Carcea I, Mitre M, Chao MV, Froemke RC, Tsien RW. Oxytocin Transforms Firing Mode of CA2 Hippocampal Neurons. Neuron 2018; 100:593-608.e3. [PMID: 30293821 DOI: 10.1016/j.neuron.2018.09.008] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 01/03/2018] [Accepted: 09/04/2018] [Indexed: 01/30/2023]
Abstract
Oxytocin is an important neuromodulator in the mammalian brain that increases information salience and circuit plasticity, but its signaling mechanisms and circuit effect are not fully understood. Here we report robust oxytocinergic modulation of intrinsic properties and circuit operations in hippocampal area CA2, a region of emerging importance for hippocampal function and social behavior. Upon oxytocin receptor activation, CA2 pyramidal cells depolarize and fire bursts of action potentials, a consequence of phospholipase C signaling to modify two separate voltage-dependent ionic processes. A reduction of potassium current carried by KCNQ-based M channels depolarizes the cell; protein kinase C activity attenuates spike rate of rise and overshoot, dampening after-hyperpolarizations. These actions, in concert with activation of fast-spiking interneurons, promote repetitive firing and CA2 bursting; bursting then governs short-term plasticity of CA2 synaptic transmission onto CA1 and, thus, efficacy of information transfer in the hippocampal network.
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Affiliation(s)
- Natasha N Tirko
- NYU Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA
| | - Katherine W Eyring
- NYU Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA
| | - Ioana Carcea
- NYU Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA; Skirball Institute, New York University School of Medicine, New York, NY 10016, USA; Department of Otolaryngology, New York University School of Medicine, New York, NY 10016, USA
| | - Mariela Mitre
- NYU Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA; Skirball Institute, New York University School of Medicine, New York, NY 10016, USA; Department of Otolaryngology, New York University School of Medicine, New York, NY 10016, USA
| | - Moses V Chao
- NYU Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA; Skirball Institute, New York University School of Medicine, New York, NY 10016, USA
| | - Robert C Froemke
- NYU Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA; Skirball Institute, New York University School of Medicine, New York, NY 10016, USA; Department of Otolaryngology, New York University School of Medicine, New York, NY 10016, USA
| | - Richard W Tsien
- NYU Neuroscience Institute, New York University School of Medicine, New York, NY 10016, USA.
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29
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Diehl GW, Hon OJ, Leutgeb S, Leutgeb JK. Stability of medial entorhinal cortex representations over time. Hippocampus 2018; 29:284-302. [PMID: 30175425 DOI: 10.1002/hipo.23017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 07/02/2018] [Accepted: 07/19/2018] [Indexed: 02/02/2023]
Abstract
Distinct functional cell types in the medial entorhinal cortex (mEC) have been shown to represent different aspects of experiences. To further characterize mEC cell populations, we examined whether spatial representations of neurons in mEC superficial layers depended on the scale of the environment and changed over extended time periods. Accordingly, mEC cells were recorded while rats repeatedly foraged in a small or a large environment in sessions that were separated by time intervals from minutes to hours. Comparing between large and small environments, we found that the overall precision of grid and non-grid cell spatial maps was higher in smaller environments. When examining the stability of spatial firing patterns over time, differences and similarities were observed across cell types. Within-session stability was higher for grid cells than for non-grid cell populations. Despite differences in baseline stability between cell types, stability levels remained consistent over time between sessions, up to 1 hr. Even for sessions separated by 6 hrs, activity patterns of grid cells and of most non-grid cells lacked any systematic decrease in spatial similarity over time. However, a subset of ~15% of mEC non-grid cells recorded preferentially from layer III exhibited dramatic, time dependent changes in firing patterns across 6 hrs, reminiscent of previous characterizations of the hippocampal CA2 subregion. Collectively, our data suggest that mEC grid cell input to hippocampus in conjunction with many time invariant non-grid cells may aid in stabilizing hippocampal spatial maps, while a subset of time varying non-grid cells could provide complementary temporal information.
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Affiliation(s)
- Geoffrey W Diehl
- Neurobiology Section and Center for Neural Circuits and Behavior, Division of Biological Sciences, University of California, La Jolla, California
| | - Olivia J Hon
- Neurobiology Section and Center for Neural Circuits and Behavior, Division of Biological Sciences, University of California, La Jolla, California
| | - Stefan Leutgeb
- Neurobiology Section and Center for Neural Circuits and Behavior, Division of Biological Sciences, University of California, La Jolla, California.,Kavli Institute for Brain and Mind, University of California, La Jolla, California
| | - Jill K Leutgeb
- Neurobiology Section and Center for Neural Circuits and Behavior, Division of Biological Sciences, University of California, La Jolla, California
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30
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Choi G, Lee J, Kim H, Jang J, Im C, Jeon N, Jung W. Image-guided recording system for spatial and temporal mapping of neuronal activities in brain slice. JOURNAL OF BIOPHOTONICS 2018; 11:e201700243. [PMID: 29215208 DOI: 10.1002/jbio.201700243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/10/2017] [Indexed: 06/07/2023]
Abstract
In this study, we introduce the novel image-guided recording system (IGRS) for efficient interpretation of neuronal activities in the brain slice. IGRS is designed to combine microelectrode array (MEA) and optical coherence tomography at the customized upright microscope. It allows to record multi-site neuronal signals and image of the volumetric brain anatomy in a single body configuration. For convenient interconnection between a brain image and neuronal signals, we developed the automatic mapping protocol that enables us to project acquired neuronal signals on a brain image. To evaluate the performance of IGRS, hippocampal signals of the brain slice were monitored, and corresponding with two-dimensional neuronal maps were successfully reconstructed. Our results indicated that IGRS and mapping protocol can provide the intuitive information regarding long-term and multi-sites neuronal signals. In particular, the temporal and spatial mapping capability of neuronal signals would be a very promising tool to observe and analyze the massive neuronal activity and connectivity in MEA-based electrophysiological studies.
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Affiliation(s)
- Geonho Choi
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Jeonghyeon Lee
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Hyeongeun Kim
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Jaemyung Jang
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, Republic of Korea
| | - Changkyun Im
- School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Republic of Korea
| | - Nooli Jeon
- School of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Republic of Korea
| | - Woonggyu Jung
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
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31
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Raveau M, Polygalov D, Boehringer R, Amano K, Yamakawa K, McHugh TJ. Alterations of in vivo CA1 network activity in Dp(16)1Yey Down syndrome model mice. eLife 2018; 7:31543. [PMID: 29485402 PMCID: PMC5841929 DOI: 10.7554/elife.31543] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 02/25/2018] [Indexed: 12/14/2022] Open
Abstract
Down syndrome, the leading genetic cause of intellectual disability, results from an extra-copy of chromosome 21. Mice engineered to model this aneuploidy exhibit Down syndrome-like memory deficits in spatial and contextual tasks. While abnormal neuronal function has been identified in these models, most studies have relied on in vitro measures. Here, using in vivo recording in the Dp(16)1Yey model, we find alterations in the organization of spiking of hippocampal CA1 pyramidal neurons, including deficits in the generation of complex spikes. These changes lead to poorer spatial coding during exploration and less coordinated activity during sharp-wave ripples, events involved in memory consolidation. Further, the density of CA1 inhibitory neurons expressing neuropeptide Y, a population key for the generation of pyramidal cell bursts, were significantly increased in Dp(16)1Yey mice. Our data refine the ‘over-suppression’ theory of Down syndrome pathophysiology and suggest specific neuronal subtypes involved in hippocampal dysfunction in these model mice.
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Affiliation(s)
- Matthieu Raveau
- Laboratory for Neurogenetics, RIKEN, Brain Science Institute, Saitama, Japan
| | - Denis Polygalov
- Laboratory for Circuit and Behavioral Physiology, RIKEN, Brain Science Institute, Saitama, Japan
| | - Roman Boehringer
- Laboratory for Circuit and Behavioral Physiology, RIKEN, Brain Science Institute, Saitama, Japan
| | - Kenji Amano
- Laboratory for Neurogenetics, RIKEN, Brain Science Institute, Saitama, Japan
| | - Kazuhiro Yamakawa
- Laboratory for Neurogenetics, RIKEN, Brain Science Institute, Saitama, Japan
| | - Thomas J McHugh
- Laboratory for Circuit and Behavioral Physiology, RIKEN, Brain Science Institute, Saitama, Japan
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32
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Unfolding the cognitive map: The role of hippocampal and extra-hippocampal substrates based on a systems analysis of spatial processing. Neurobiol Learn Mem 2018; 147:90-119. [DOI: 10.1016/j.nlm.2017.11.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 11/17/2017] [Accepted: 11/21/2017] [Indexed: 01/03/2023]
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33
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Recording Field Potentials and Synaptic Plasticity From Freely Behaving Rodents. HANDBOOK OF BEHAVIORAL NEUROSCIENCE 2018. [DOI: 10.1016/b978-0-12-812028-6.00001-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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34
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Raam T, McAvoy KM, Besnard A, Veenema AH, Sahay A. Hippocampal oxytocin receptors are necessary for discrimination of social stimuli. Nat Commun 2017; 8:2001. [PMID: 29222469 PMCID: PMC5722862 DOI: 10.1038/s41467-017-02173-0] [Citation(s) in RCA: 170] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 11/10/2017] [Indexed: 12/23/2022] Open
Abstract
Oxytocin receptor (Oxtr) signaling in neural circuits mediating discrimination of social stimuli and affiliation or avoidance behavior is thought to guide social recognition. Remarkably, the physiological functions of Oxtrs in the hippocampus are not known. Here we demonstrate using genetic and pharmacological approaches that Oxtrs in the anterior dentate gyrus (aDG) and anterior CA2/CA3 (aCA2/CA3) of mice are necessary for discrimination of social, but not non-social, stimuli. Further, Oxtrs in aCA2/CA3 neurons recruit a population-based coding mechanism to mediate social stimuli discrimination. Optogenetic terminal-specific attenuation revealed a critical role for aCA2/CA3 outputs to posterior CA1 for discrimination of social stimuli. In contrast, aCA2/CA3 projections to aCA1 mediate discrimination of non-social stimuli. These studies identify a role for an aDG-CA2/CA3 axis of Oxtr expressing cells in discrimination of social stimuli and delineate a pathway relaying social memory computations in the anterior hippocampus to the posterior hippocampus to guide social recognition.
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Affiliation(s)
- Tara Raam
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA.,Harvard Stem Cell Institute, Cambridge, MA, 02138, USA.,Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA.,Program in Neuroscience, Harvard Medical School, Boston, MA, 02115, USA
| | - Kathleen M McAvoy
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA.,Harvard Stem Cell Institute, Cambridge, MA, 02138, USA.,Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Antoine Besnard
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA.,Harvard Stem Cell Institute, Cambridge, MA, 02138, USA.,Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Alexa H Veenema
- Department of Psychology, Michigan State University, East Lansing, MI, 48824, USA
| | - Amar Sahay
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA. .,Harvard Stem Cell Institute, Cambridge, MA, 02138, USA. .,Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA. .,Program in Neuroscience, Harvard Medical School, Boston, MA, 02115, USA. .,Broad Institute of Harvard and MIT, Cambridge, MA, 02142, USA.
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35
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Mercer A, Thomson AM. Cornu Ammonis Regions-Antecedents of Cortical Layers? Front Neuroanat 2017; 11:83. [PMID: 29018334 PMCID: PMC5622992 DOI: 10.3389/fnana.2017.00083] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 09/08/2017] [Indexed: 12/13/2022] Open
Abstract
Studying neocortex and hippocampus in parallel, we are struck by the similarities. All three to four layered allocortices and the six layered mammalian neocortex arise in the pallium. All receive and integrate multiple cortical and subcortical inputs, provide multiple outputs and include an array of neuronal classes. During development, each cell positions itself to sample appropriate local and distant inputs and to innervate appropriate targets. Simpler cortices had already solved the need to transform multiple coincident inputs into serviceable outputs before neocortex appeared in mammals. Why then do phylogenetically more recent cortices need multiple pyramidal cell layers? A simple answer is that more neurones can compute more complex functions. The dentate gyrus and hippocampal CA regions-which might be seen as hippocampal antecedents of neocortical layers-lie side by side, albeit around a tight bend. Were the millions of cells of rat neocortex arranged in like fashion, the surface area of the CA pyramidal cell layers would be some 40 times larger. Even if evolution had managed to fold this immense sheet into the space available, the distances between neurones that needed to be synaptically connected would be huge and to maintain the speed of information transfer, massive, myelinated fiber tracts would be needed. How much more practical to stack the "cells that fire and wire together" into narrow columns, while retaining the mechanisms underlying the extraordinary precision with which circuits form. This demonstrably efficient arrangement presents us with challenges, however, not the least being to categorize the baffling array of neuronal subtypes in each of five "pyramidal layers." If we imagine the puzzle posed by this bewildering jumble of apical dendrites, basal dendrites and axons, from many different pyramidal and interneuronal classes, that is encountered by a late-arriving interneurone insinuating itself into a functional circuit, we can perhaps begin to understand why definitive classification, covering every aspect of each neurone's structure and function, is such a challenge. Here, we summarize and compare the development of these two cortices, the properties of their neurones, the circuits they form and the ordered, unidirectional flow of information from one hippocampal region, or one neocortical layer, to another.
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Affiliation(s)
- Audrey Mercer
- Department of Pharmacology, School of Pharmacy, University College London, London, United Kingdom
| | - Alex M. Thomson
- Department of Pharmacology, School of Pharmacy, University College London, London, United Kingdom
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36
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Honda Y, Shibata H. Organizational connectivity among the CA1, subiculum, presubiculum, and entorhinal cortex in the rabbit. J Comp Neurol 2017; 525:3705-3741. [DOI: 10.1002/cne.24297] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 07/31/2017] [Accepted: 07/31/2017] [Indexed: 12/13/2022]
Affiliation(s)
- Yoshiko Honda
- Department of Anatomy; School of Medicine, Tokyo Women's Medical University; Tokyo Japan
| | - Hideshi Shibata
- Laboratory of Veterinary Anatomy; Institute of Agriculture, Tokyo University of Agriculture and Technology; Tokyo Japan
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37
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CA2 Pyramidal Neurons: Biophysically and Anatomically Predisposed Integrators of Cortical Sensory Information. J Neurosci 2017; 37:7564-7566. [PMID: 28821683 DOI: 10.1523/jneurosci.1405-17.2017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/08/2017] [Accepted: 07/11/2017] [Indexed: 11/21/2022] Open
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38
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Differential Expression and Cell-Type Specificity of Perineuronal Nets in Hippocampus, Medial Entorhinal Cortex, and Visual Cortex Examined in the Rat and Mouse. eNeuro 2017; 4:eN-NWR-0379-16. [PMID: 28593193 PMCID: PMC5461557 DOI: 10.1523/eneuro.0379-16.2017] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 05/18/2017] [Accepted: 05/18/2017] [Indexed: 12/21/2022] Open
Abstract
Perineuronal nets (PNNs) are specialized extracellular matrix (ECM) structures that condense around the soma and proximal dendrites of subpopulations of neurons. Emerging evidence suggests that they are involved in regulating brain plasticity. However, the expression of PNNs varies between and within brain areas. A lack of quantitative studies describing the distribution and cell-specificity of PNNs makes it difficult to reveal the functional roles of PNNs. In the current study, we examine the distribution of PNNs and the identity of PNN-enwrapped neurons in three brain areas with different cognitive functions: the dorsal hippocampus, medial entorhinal cortex (mEC) and primary visual cortex (V1). We compared rats and mice as knowledge from these species are often intermingled. The most abundant expression of PNNs was found in the mEC and V1, while dorsal hippocampus showed strikingly low levels of PNNs, apart from dense expression in the CA2 region. In hippocampus we also found apparent species differences in expression of PNNs. While we confirm that the PNNs enwrap parvalbumin-expressing (PV+) neurons in V1, we found that they mainly colocalize with excitatory CamKII-expressing neurons in CA2. In mEC, we demonstrate that in addition to PV+ cells, the PNNs colocalize with reelin-expressing stellate cells. We also show that the maturation of PNNs in mEC coincides with the formation of grid cell pattern, while PV+ cells, unlike in other cortical areas, are present from early postnatal development. Finally, we demonstrate considerable effects on the number of PSD-95-gephyrin puncta after enzymatic removal of PNNs.
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39
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Clark CA, Fernandez F, Sakhon S, Spanò G, Edgin JO. The medial temporal memory system in Down syndrome: Translating animal models of hippocampal compromise. Hippocampus 2017; 27:683-691. [PMID: 28346765 PMCID: PMC8109260 DOI: 10.1002/hipo.22724] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 09/06/2016] [Accepted: 03/07/2017] [Indexed: 01/19/2023]
Abstract
Recent studies have highlighted the dentate gyrus as a region of increased vulnerability in mouse models of Down syndrome (DS). It is unclear to what extent these findings are reflected in the memory profile of people with the condition. We developed a series of novel tasks to probe distinct medial temporal functions in children and young adults with DS, including object, spatial, and temporal order memory. Relative to mental age-matched controls (n = 45), individuals with DS (n = 28) were unimpaired on subtests involving short-term object or configural recall that was divorced from spatial or temporal contexts. By contrast, the DS group had difficulty recalling spatial locations when contextual information was salient and recalling the order in which objects were serially presented. Results are consistent with dysfunction of spatial and temporal contextual pattern separation abilities in individuals with DS, mediated by the hippocampus, including the dentate gyrus. Amidst increasing calls to bridge human and animal work, the memory profile demonstrated here in humans with DS is strikingly similar to that of the Ts65Dn mouse model of DS. The study highlights the trisynaptic circuit as a potentially fruitful intervention target to mitigate cognitive impairments associated with DS.
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Affiliation(s)
- Caron A.C. Clark
- Department of Psychology, Memory Development and Disorders Laboratory, University of Arizona, Tucson, Arizona
- Department of Educational Psychology, University of Nebraska, Lincoln, Nebraska
| | - Fabian Fernandez
- Department of Psychology, BIO5 and McKnight Brain Research Institutes, University of Arizona, Tucson, Arizona
- Department of Neurology, BIO5 and McKnight Brain Research Institutes, University of Arizona, Tucson, Arizona
| | - Stella Sakhon
- Department of Psychology, Memory Development and Disorders Laboratory, University of Arizona, Tucson, Arizona
| | - Goffredina Spanò
- Department of Psychology, Memory Development and Disorders Laboratory, University of Arizona, Tucson, Arizona
| | - Jamie O. Edgin
- Department of Psychology, Memory Development and Disorders Laboratory, University of Arizona, Tucson, Arizona
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40
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Baghcheghi Y, Salmani H, Beheshti F, Hosseini M. Contribution of Brain Tissue Oxidative Damage in Hypothyroidism-associated Learning and Memory Impairments. Adv Biomed Res 2017; 6:59. [PMID: 28584813 PMCID: PMC5450450 DOI: 10.4103/2277-9175.206699] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The brain is a critical target organ for thyroid hormones, and modifications in memory and cognition happen with thyroid dysfunction. The exact mechanisms underlying learning and memory impairments due to hypothyroidism have not been understood yet. Therefore, this review was aimed to compress the results of previous studies which have examined the contribution of brain tissues oxidative damage in hypothyroidism-associated learning and memory impairments.
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Affiliation(s)
- Yousef Baghcheghi
- Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hossein Salmani
- Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Farimah Beheshti
- Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mahmoud Hosseini
- Neurocognitive Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
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41
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Boehringer R, Polygalov D, Huang AJ, Middleton SJ, Robert V, Wintzer ME, Piskorowski RA, Chevaleyre V, McHugh TJ. Chronic Loss of CA2 Transmission Leads to Hippocampal Hyperexcitability. Neuron 2017; 94:642-655.e9. [DOI: 10.1016/j.neuron.2017.04.014] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 02/16/2017] [Accepted: 04/06/2017] [Indexed: 12/22/2022]
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42
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Györfi O, Nagy H, Bokor M, Moustafa AA, Rosenzweig I, Kelemen O, Kéri S. Reduced CA2-CA3 Hippocampal Subfield Volume Is Related to Depression and Normalized by l-DOPA in Newly Diagnosed Parkinson's Disease. Front Neurol 2017; 8:84. [PMID: 28367136 PMCID: PMC5355434 DOI: 10.3389/fneur.2017.00084] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 02/24/2017] [Indexed: 11/24/2022] Open
Abstract
Hippocampal dysfunctions may play an important role in the non-motor aspects of Parkinson’s disease (PD), including depressive and cognitive symptoms. Fine structural alterations of the hippocampus and their relationship with symptoms and medication effects are unknown in newly diagnosed PD. We measured the volume of hippocampal subfields in 35 drug-naïve, newly diagnosed PD patients without cognitive impairment and 30 matched healthy control individuals. Assessments were performed when the patients did not receive medications and after a 24-week period of l-DOPA treatment. We obtained a T1-weighted 3D magnetization-prepared rapid acquisition gradient echo image at each assessment. FreeSurfer v6.0 was used for image analysis. Results revealed a selectively decreased CA2–CA3 volume in non-medicated PD patients, which was normalized after the 24-week treatment period. Higher depressive symptoms were associated with smaller CA2–CA3 volumes. These results indicate that the CA2–CA3 subfield is structurally affected in the earliest stage of PD in the absence of cognitive impairment. This structural anomaly, normalized by l-DOPA, is related to depressive non-motor symptoms.
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Affiliation(s)
- Orsolya Györfi
- Department of Neurology, Nyírö Gyula Hospital, National Institute of Psychiatry and Addictions , Budapest , Hungary
| | - Helga Nagy
- National Institute for Medical Rehabilitation, Budapest, Hungary; Department of Neurology, Semmelweis University, Budapest, Hungary
| | - Magdolna Bokor
- Department of Neurology, Nyírö Gyula Hospital, National Institute of Psychiatry and Addictions , Budapest , Hungary
| | - Ahmed A Moustafa
- School of Social Sciences and Psychology, Western Sydney University, Sydney, NSW, Australia; Marcs Institute for Brain and Behavior, Western Sydney University, Sydney, NSW, Australia
| | - Ivana Rosenzweig
- Sleep and Brain Plasticity Centre, Department of Neuroimaging, IOPPN, King's College and Imperial College London, London, UK; Sleep Disorders Centre, Guy's Hospital, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Oguz Kelemen
- Faculty of Medicine, Department of Behavioral Sciences, University of Szeged , Szeged , Hungary
| | - Szabolcs Kéri
- Department of Neurology, Nyírö Gyula Hospital, National Institute of Psychiatry and Addictions, Budapest, Hungary; Department of Cognitive Science, Budapest University of Technology and Economics, Budapest, Hungary; Faculty of Medicine, Department of Physiology, University of Szeged, Szeged, Hungary
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43
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Graph Theoretic and Motif Analyses of the Hippocampal Neuron Type Potential Connectome. eNeuro 2016; 3:eN-NWR-0205-16. [PMID: 27896314 PMCID: PMC5114701 DOI: 10.1523/eneuro.0205-16.2016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 10/21/2016] [Accepted: 10/25/2016] [Indexed: 01/11/2023] Open
Abstract
We computed the potential connectivity map of all known neuron types in the rodent hippocampal formation by supplementing scantly available synaptic data with spatial distributions of axons and dendrites from the open-access knowledge base Hippocampome.org. The network that results from this endeavor, the broadest and most complete for a mammalian cortical region at the neuron-type level to date, contains more than 3200 connections among 122 neuron types across six subregions. Analyses of these data using graph theory metrics unveil the fundamental architectural principles of the hippocampal circuit. Globally, we identify a highly specialized topology minimizing communication cost; a modular structure underscoring the prominence of the trisynaptic loop; a core set of neuron types serving as information-processing hubs as well as a distinct group of particular antihub neurons; a nested, two-tier rich club managing much of the network traffic; and an innate resilience to random perturbations. At the local level, we uncover the basic building blocks, or connectivity patterns, that combine to produce complex global functionality, and we benchmark their utilization in the circuit relative to random networks. Taken together, these results provide a comprehensive connectivity profile of the hippocampus, yielding novel insights on its functional operations at the computationally crucial level of neuron types.
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Matsumoto N, Okamoto K, Takagi Y, Ikegaya Y. 3-Hz subthreshold oscillations of CA2 neurons In vivo. Hippocampus 2016; 26:1570-1578. [PMID: 27650674 DOI: 10.1002/hipo.22657] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2016] [Indexed: 12/12/2022]
Abstract
The CA2 region is unique in the hippocampus; it receives direct synaptic innervations from several hypothalamic nuclei and expresses various receptors of neuromodulators, including adenosine, vasopressin, and oxytocin. Furthermore, the CA2 region may have distinct brain functions, such as the control of instinctive and social behaviors; however, little is known about the dynamics of the subthreshold membrane potentials of CA2 neurons in vivo. We conducted whole-cell current-clamp recordings from CA2 pyramidal cells in urethane-anesthetized mice and monitored the intrinsic fluctuations in their membrane potentials. The CA2 pyramidal cells emitted spontaneous action potentials at mean firing rates of ∼0.8 Hz. In approximately half of the neurons, the subthreshold membrane potential oscillated at ∼3 Hz. In two neurons, we obtained simultaneous recordings of local field potentials from the CA1 stratum radiatum and demonstrated that the 3-Hz oscillations of CA2 neurons were not correlated with CA1 field potentials. In tetrodotoxin-perfused acute hippocampal slices, the membrane potentials of CA2 pyramidal cells were not preferentially entrained to 3-Hz sinusoidal current inputs, which suggest that intracellular 3-Hz oscillations reflect the neuronal dynamics of the surrounding networks. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Nobuyoshi Matsumoto
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Kazuki Okamoto
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yuki Takagi
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yuji Ikegaya
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.,Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita City, Osaka, Japan
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45
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Daugherty AM, Bender AR, Yuan P, Raz N. Changes in Search Path Complexity and Length During Learning of a Virtual Water Maze: Age Differences and Differential Associations with Hippocampal Subfield Volumes. Cereb Cortex 2016; 26:2391-401. [PMID: 25838036 PMCID: PMC4869801 DOI: 10.1093/cercor/bhv061] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Impairment of hippocampus-dependent cognitive processes has been proposed to underlie age-related deficits in navigation. Animal studies suggest a differential role of hippocampal subfields in various aspects of navigation, but that hypothesis has not been tested in humans. In this study, we examined the association between volume of hippocampal subfields and age differences in virtual spatial navigation. In a sample of 65 healthy adults (age 19-75 years), advanced age was associated with a slower rate of improvement operationalized as shortening of the search path over 25 learning trials on a virtual Morris water maze task. The deficits were partially explained by greater complexity of older adults' search paths. Larger subiculum and entorhinal cortex volumes were associated with a faster decrease in search path complexity, which in turn explained faster shortening of search distance. Larger Cornu Ammonis (CA)1-2 volume was associated with faster distance shortening, but not in path complexity reduction. Age differences in regional volumes collectively accounted for 23% of the age-related variance in navigation learning. Independent of subfield volumes, advanced age was associated with poorer performance across all trials, even after reaching the asymptote. Thus, subiculum and CA1-2 volumes were associated with speed of acquisition, but not magnitude of gains in virtual maze navigation.
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Affiliation(s)
| | | | - Peng Yuan
- Institute of Gerontology
- Psychology Department, Wayne State University, Detroit, MI 48202, USA
| | - Naftali Raz
- Institute of Gerontology
- Psychology Department, Wayne State University, Detroit, MI 48202, USA
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46
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Age-Dependent Specific Changes in Area CA2 of the Hippocampus and Social Memory Deficit in a Mouse Model of the 22q11.2 Deletion Syndrome. Neuron 2016; 89:163-76. [PMID: 26748091 DOI: 10.1016/j.neuron.2015.11.036] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 09/23/2015] [Accepted: 11/18/2015] [Indexed: 11/23/2022]
Abstract
Several neuropsychiatric disorders are associated with cognitive and social dysfunction. Postmortem studies of patients with schizophrenia have revealed specific changes in area CA2, a long-overlooked region of the hippocampus recently found to be critical for social memory formation. To examine how area CA2 is altered in psychiatric illness, we used the Df(16)A(+/-) mouse model of the 22q11.2 microdeletion, a genetic risk factor for developing several neuropsychiatric disorders, including schizophrenia. We report several age-dependent CA2 alterations: a decrease in the density of parvalbumin-expressing interneurons, a reduction in the amount of feedforward inhibition, and a change in CA2 pyramidal-neuron intrinsic properties. Furthermore, we found that area CA2 is less plastic in Df(16)A(+/-) mice, making it nearly impossible to evoke action potential firing in CA2 pyramidal neurons. Finally, we show that Df(16)A(+/-) mice display impaired social cognition, providing a potential mechanism and a neural substrate for this impairment in psychiatric disorders.
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47
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Hullinger R, Puglielli L. Molecular and cellular aspects of age-related cognitive decline and Alzheimer's disease. Behav Brain Res 2016; 322:191-205. [PMID: 27163751 DOI: 10.1016/j.bbr.2016.05.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 04/19/2016] [Accepted: 05/03/2016] [Indexed: 01/14/2023]
Abstract
As the population of people aged 60 or older continues to rise, it has become increasingly important to understand the molecular basis underlying age-related cognitive decline. In fact, a better understanding of aging biology will help us identify ways to maintain high levels of cognitive functioning throughout the aging process. Many cellular and molecular aspects of brain aging are shared with other organ systems; however, certain age-related changes are unique to the nervous system due to its structural, cellular and molecular complexity. Importantly, the brain appears to show differential changes throughout the aging process, with certain regions (e.g. frontal and temporal regions) being more vulnerable than others (e.g. brain stem). Within the medial temporal lobe, the hippocampus is especially susceptible to age-related changes. The important role of the hippocampus in age-related cognitive decline and in vulnerability to disease processes such as Alzheimer's disease has prompted this review, which will focus on the complexity of changes that characterize aging, and on the molecular connections that exist between normal aging and Alzheimer's disease. Finally, it will discuss behavioral interventions and emerging insights for promoting healthy cognitive aging.
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Affiliation(s)
- Rikki Hullinger
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Luigi Puglielli
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA; Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA; Wisconsin Alzheimer's Disease Research Center, University of Wisconsin-Madison, Madison, WI 53705, USA; Geriatric Research Education Clinical Center, VA Medical Center, Madison, WI 53705, USA.
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48
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Temporal context processing within hippocampal subfields. Neuroimage 2016; 134:261-269. [PMID: 27039142 DOI: 10.1016/j.neuroimage.2016.03.048] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Revised: 02/16/2016] [Accepted: 03/18/2016] [Indexed: 11/20/2022] Open
Abstract
The episodic memory system can differentiate similar events based on the temporal information associated with the events. Temporal context, which is at least partially determined by the events that precede or follow the critical event, may be a cue to differentiate events. The purpose of the present study is to investigate whether the hippocampal dentate gyrus (DG)/CA3 and CA1 subfields are sensitive to changes in temporal context and, if so, whether the subregions show a linear or threshold-like response to similar temporal contexts. Participants incidentally encoded a series of object picture triplets and 20 of them were included in final analyses. The third picture in each triplet was operationally defined as the target and the first two pictures served as temporal context for the target picture. Each target picture was presented twice with temporal context manipulated to be either repeated, high similarity, low similarity, or new on the second presentation. We extracted beta parameters for the repeated target as a function of the type of temporal context. We expected to see repetition suppression, a reduction in the beta values, in response to repetition of the target. If temporal context information is included in the representation of the target within a given region, this repetition suppression should be greater for target images that were preceded by their original context than for target images preceded by a new context. Neuroimaging results showed that CA1, but not DG/CA3, modifies the target's representation based on its temporal context. Right CA1 did not distinguish high similarity temporal context from repeated context but did distinguish low similarity temporal context from repeated context. These results indicate that CA1 is sensitive to temporal context and suggest that it does not differentiate between a substantially similar temporal context and an identical temporal context. In contrast, DG/CA3 does not appear to process temporal context as defined in the current experiment.
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49
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Faraji J, Soltanpour N, Moeeini R, Hosseini SA, Pakdel S, Moharrerie A, Arjang K, Soltanpour N, Metz GA. Regional vulnerability of the hippocampus to repeated motor activity deprivation. Behav Brain Res 2016; 301:178-89. [DOI: 10.1016/j.bbr.2015.12.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 11/11/2015] [Accepted: 12/18/2015] [Indexed: 12/12/2022]
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50
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Di Filippo M, de Iure A, Giampà C, Chiasserini D, Tozzi A, Orvietani PL, Ghiglieri V, Tantucci M, Durante V, Quiroga-Varela A, Mancini A, Costa C, Sarchielli P, Fusco FR, Calabresi P. Persistent activation of microglia and NADPH oxidase [corrected] drive hippocampal dysfunction in experimental multiple sclerosis. Sci Rep 2016; 6:20926. [PMID: 26887636 PMCID: PMC4757867 DOI: 10.1038/srep20926] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 01/13/2016] [Indexed: 01/08/2023] Open
Abstract
Cognitive impairment is common in multiple sclerosis (MS). Unfortunately, the synaptic and molecular mechanisms underlying MS-associated cognitive dysfunction are largely unknown. We explored the presence and the underlying mechanism of cognitive and synaptic hippocampal dysfunction during the remission phase of experimental MS. Experiments were performed in a chronic-relapsing experimental autoimmune encephalomyelitis (EAE) model of MS, after the resolution of motor deficits. Immunohistochemistry and patch-clamp recordings were performed in the CA1 hippocampal area. The hole-board was utilized as cognitive/behavioural test. In the remission phase of experimental MS, hippocampal microglial cells showed signs of activation, CA1 hippocampal synapses presented an impaired long-term potentiation (LTP) and an alteration of spatial tests became evident. The activation of hippocampal microglia mediated synaptic and cognitive/behavioural alterations during EAE. Specifically, LTP blockade was found to be caused by the reactive oxygen species (ROS)-producing enzyme nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. We suggest that in the remission phase of experimental MS microglia remains activated, causing synaptic dysfunctions mediated by NADPH oxidase. Inhibition of microglial activation and NADPH oxidase may represent a promising strategy to prevent neuroplasticity impairment associated with active neuro-inflammation, with the aim to improve cognition and counteract MS disease progression.
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Affiliation(s)
- Massimiliano Di Filippo
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia, S. Andrea delle Fratte, 06132 Perugia, Italy
| | - Antonio de Iure
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia, S. Andrea delle Fratte, 06132 Perugia, Italy
| | - Carmela Giampà
- IRCCS, Fondazione Santa Lucia, via del Fosso di Fiorano 64, 00143, Rome, Italy
| | - Davide Chiasserini
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia, S. Andrea delle Fratte, 06132 Perugia, Italy
| | - Alessandro Tozzi
- IRCCS, Fondazione Santa Lucia, via del Fosso di Fiorano 64, 00143, Rome, Italy.,Sezione di Fisiologia e Biochimica, Dipartimento di Medicina Sperimentale, Università degli Studi di Perugia, S. Andrea delle Fratte, 06132 Perugia, Italy
| | - Pier Luigi Orvietani
- Sezione di Fisiologia e Biochimica, Dipartimento di Medicina Sperimentale, Università degli Studi di Perugia, S. Andrea delle Fratte, 06132 Perugia, Italy
| | - Veronica Ghiglieri
- IRCCS, Fondazione Santa Lucia, via del Fosso di Fiorano 64, 00143, Rome, Italy
| | - Michela Tantucci
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia, S. Andrea delle Fratte, 06132 Perugia, Italy
| | - Valentina Durante
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia, S. Andrea delle Fratte, 06132 Perugia, Italy
| | - Ana Quiroga-Varela
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia, S. Andrea delle Fratte, 06132 Perugia, Italy
| | - Andrea Mancini
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia, S. Andrea delle Fratte, 06132 Perugia, Italy
| | - Cinzia Costa
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia, S. Andrea delle Fratte, 06132 Perugia, Italy
| | - Paola Sarchielli
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia, S. Andrea delle Fratte, 06132 Perugia, Italy
| | | | - Paolo Calabresi
- Clinica Neurologica, Dipartimento di Medicina, Università degli Studi di Perugia, Ospedale Santa Maria della Misericordia, S. Andrea delle Fratte, 06132 Perugia, Italy.,IRCCS, Fondazione Santa Lucia, via del Fosso di Fiorano 64, 00143, Rome, Italy
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