1
|
Tarhan M, Hartl T, Shchyglo O, Colitti-Klausnitzer J, Kuhla A, Breuer TM, Manahan-Vaughan D. Changes in hippocampal volume, synaptic plasticity and amylin sensitivity in an animal model of type 2 diabetes are associated with increased vulnerability to amyloid-beta in advancing age. Front Aging Neurosci 2024; 16:1373477. [PMID: 38974903 PMCID: PMC11224464 DOI: 10.3389/fnagi.2024.1373477] [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: 01/19/2024] [Accepted: 05/28/2024] [Indexed: 07/09/2024] Open
Abstract
Type-2 diabetes (T2D) is a metabolic disorder that is considered a risk factor for Alzheimer's disease (AD). Cognitive impairment can arise due to hypoglycemia associated with T2D, and hyperamylinemia associated with insulin resistance can enhance AD pathology. We explored whether changes occur in the hippocampus in aging (6-12 months old) female V-Lep○b-/- transgenic (tg) mice, comprising an animal model of T2D. We also investigated whether an increase in vulnerability to Aβ (1-42), a known pathological hallmark of AD, is evident. Using magnetic resonance imaging we detected significant decreases in hippocampal brain volume in female tg-mice compared to wild-type (wt) littermates. Long-term potentiation (LTP) was impaired in tg compared to wt mice. Treatment of the hippocampus with Aβ (1-42) elicited a stronger debilitation of LTP in tg compared to wt mice. Treatment with an amylin antagonist (AC187) significantly enhanced LTP in wt and tg mice, and rescued LTP in Aβ (1-42)-treated tg mice. Taken together our data indicate that a T2D-like state results in an increased vulnerability of the hippocampus to the debilitating effects of Aβ (1-42) and that effects are mediated in part by changes in amylin receptor signaling.
Collapse
Affiliation(s)
- Melih Tarhan
- Department of Neurophysiology, Institute of Physiology, Ruhr University Bochum, Bochum, Germany
- International Graduate School of Neuroscience, Bochum, Germany
| | - Tim Hartl
- Department of Neurophysiology, Institute of Physiology, Ruhr University Bochum, Bochum, Germany
- International Graduate School of Neuroscience, Bochum, Germany
| | - Olena Shchyglo
- Department of Neurophysiology, Institute of Physiology, Ruhr University Bochum, Bochum, Germany
| | | | - Angela Kuhla
- Rudolf Zenker Institute for Experimental Surgery, Rostock University Medical Center, Rostock, Germany
| | | | - Denise Manahan-Vaughan
- Department of Neurophysiology, Institute of Physiology, Ruhr University Bochum, Bochum, Germany
- International Graduate School of Neuroscience, Bochum, Germany
| |
Collapse
|
2
|
Puthusseryppady V, Cossio D, Yu S, Rezwana F, Hegarty M, Jacobs EG, Chrastil ER. Less spatial exploration is associated with poorer spatial memory in midlife adults. Front Aging Neurosci 2024; 16:1382801. [PMID: 38919601 PMCID: PMC11196421 DOI: 10.3389/fnagi.2024.1382801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 04/22/2024] [Indexed: 06/27/2024] Open
Abstract
Introduction Despite its importance for navigation, very little is known about how the normal aging process affects spatial exploration behavior. We aimed to investigate: (1) how spatial exploration behavior may be altered early in the aging process, (2) the relationship between exploration behavior and subsequent spatial memory, and (3) whether exploration behavior can classify participants according to age. Methods Fifty healthy young (aged 18-28) and 87 healthy midlife adults (aged 43-61) freely explored a desktop virtual maze, learning the locations of nine target objects. Various exploration behaviors (object visits, distance traveled, turns made, etc.) were measured. In the test phase, participants navigated from one target object to another without feedback, and their wayfinding success (% correct trials) was measured. Results In the exploration phase, midlife adults exhibited less exploration overall compared to young adults, and prioritized learning target object locations over maze layout. In the test phase, midlife adults exhibited less wayfinding success when compared to the young adults. Furthermore, following principal components analysis (PCA), regression analyses indicated that both exploration quantity and quality components were associated with wayfinding success in the midlife group, but not the young adults. Finally, we could classify participants according to age with similar accuracy using either their exploration behavior or wayfinding success scores. Discussion Our results aid in the understanding of how aging impacts spatial exploration, and encourages future investigations into how pathological aging may affect spatial exploration behavior.
Collapse
Affiliation(s)
- Vaisakh Puthusseryppady
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
| | - Daniela Cossio
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
| | - Shuying Yu
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Farnaz Rezwana
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
| | - Mary Hegarty
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Emily G. Jacobs
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, United States
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Elizabeth R. Chrastil
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
| |
Collapse
|
3
|
Caragea VM, Manahan-Vaughan D. Bidirectional Regulation of Hippocampal Synaptic Plasticity and Modulation of Cumulative Spatial Memory by Dopamine D2-Like Receptors. Front Behav Neurosci 2022; 15:803574. [PMID: 35095441 PMCID: PMC8789653 DOI: 10.3389/fnbeh.2021.803574] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 12/20/2021] [Indexed: 01/11/2023] Open
Abstract
Dopamine is a key factor in the enablement of cognition and hippocampal information processing. Its action in the hippocampus is mediated by D1/D5 and D2-like (D2, D3, D4) receptors. While D1/D5-receptors are well recognized as strong modulators of hippocampal synaptic plasticity and information storage, much less is known about the role of D2-like receptors (D2R) in these processes. Here, we explored to what extent D2R contribute to synaptic plasticity and cumulative spatial memory derived from semantic and episodic-like information storage. In freely behaving adult rats, we also assessed to what extent short and long-term forms of synaptic plasticity are influenced by pharmacological activation or blockade of D2R. Antagonism of D2R by means of intracerebral treatment with remoxipride, completely prevented the expression of both short-term (<1 h) and long-term potentiation (>4 h), as well as the expression of short-term depression (STD, <1 h) in the hippocampal CA1 region. Scrutiny of involvement of D2R in spatial learning revealed that D2R-antagonism prevented retention of a semantic spatial memory task, and also significantly impaired retention of recent spatiotemporal aspects of an episodic-like memory task. Taken together, these findings indicate that D2R are required for bidirectional synaptic plasticity in the hippocampal CA1 region. Furthermore, they are critically involved in enabling cumulative and episodic-like forms of spatial learning.
Collapse
Affiliation(s)
- Violeta-Maria Caragea
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany
- International Graduate School of Neuroscience, Ruhr University Bochum, Bochum, Germany
| | - Denise Manahan-Vaughan
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany
- International Graduate School of Neuroscience, Ruhr University Bochum, Bochum, Germany
- *Correspondence: Denise Manahan-Vaughan
| |
Collapse
|
4
|
Gargano A, Beins E, Zimmer A, Bilkei-Gorzo A. Lack of Cannabinoid Receptor Type-1 Leads to Enhanced Age-Related Neuronal Loss in the Locus Coeruleus. Int J Mol Sci 2020; 22:ijms22010005. [PMID: 33374940 PMCID: PMC7792602 DOI: 10.3390/ijms22010005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 02/05/2023] Open
Abstract
Our laboratory and others have previously shown that cannabinoid receptor type-1 (CB1r) activity is neuroprotective and a modulator of brain ageing; a genetic disruption of CB1r signaling accelerates brain ageing, whereas the pharmacological stimulation of CB1r activity had the opposite effect. In this study, we have investigated if the lack of CB1r affects noradrenergic neurons in the locus coeruleus (LC), which are vulnerable to age-related changes; their numbers are reduced in patients with neurodegenerative diseases and probably also in healthy aged individuals. Thus, we compared LC neuronal numbers between cannabinoid 1 receptor knockout (Cnr1−/−) mice and their wild-type littermates. Our results reveal that old Cnr1−/− mice have less noradrenergic neurons compared to their age-matched wild-type controls. This result was also confirmed by the analysis of the density of noradrenergic terminals which proved that Cnr1−/− mice had less compared to the wild-type controls. Additionally, we assessed pro-inflammatory glial activity in the LC. Although the density of microglia in Cnr1−/− mice was enhanced, they did not show enhanced inflammatory profile. We hypothesize that CB1r activity is necessary for the protection of noradrenergic neurons, but its anti-inflammatory effect probably only plays a minor role in it.
Collapse
Affiliation(s)
- Alessandra Gargano
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany; (A.G.); (E.B.); (A.Z.)
| | - Eva Beins
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany; (A.G.); (E.B.); (A.Z.)
- Institute of Human Genetics, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Andreas Zimmer
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany; (A.G.); (E.B.); (A.Z.)
| | - Andras Bilkei-Gorzo
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany; (A.G.); (E.B.); (A.Z.)
- Correspondence: ; Tel.: +49-0228-6885-317
| |
Collapse
|
5
|
|
6
|
Hippocampal Subregion Transcriptomic Profiles Reflect Strategy Selection during Cognitive Aging. J Neurosci 2020; 40:4888-4899. [PMID: 32376783 DOI: 10.1523/jneurosci.2944-19.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 04/08/2020] [Accepted: 04/30/2020] [Indexed: 12/18/2022] Open
Abstract
Age-related cognitive impairments are associated with differentially expressed genes (DEGs) linked to defined neural systems; however, studies examining multiple regions of the hippocampus fail to find links between behavior and transcription in the dentate gyrus (DG). We hypothesized that use of a task requiring intact DG function would emphasize molecular signals in the DG associated with a decline in performance. We used a water maze beacon discrimination task to characterize young and middle-age male F344 rats, followed by a spatial reference memory probe trial test. Middle-age rats showed increased variability in discriminating two identical beacons. Use of an allocentric strategy and formation of a spatial reference memory were not different between age groups; however, older animals compensated for impaired beacon discrimination through greater reliance on spatial reference memory. mRNA sequencing of hippocampal subregions indicated DEGs in the DG of middle-age rats, linked to synaptic function and neurogenesis, correlated with beacon discrimination performance, suggesting that senescence of the DG underlies the impairment. Few genes correlated with spatial memory across age groups, with a greater number in region CA1. Age-related CA1 DEGs, correlated with spatial memory, were linked to regulation of neural activity. These results indicate that the beacon task is sensitive to impairment in middle age, and distinct gene profiles are observed in neural circuits that underlie beacon discrimination performance and allocentric memory. The use of different strategies in older animals and associated transcriptional profiles could provide an animal model for examining cognitive reserve and neural compensation of aging.SIGNIFICANCE STATEMENT Hippocampal subregions are thought to differentially contribute to memory. We took advantage of age-related variability in performance on a water maze beacon task and next-generation sequencing to test the hypothesis that aging of the dentate gyrus is linked to impaired beacon discrimination and compensatory use of allocentric memory. The dentate gyrus expressed synaptic function and neurogenesis genes correlated with beacon discrimination in middle-age animals. Spatial reference memory was associated with CA1 transcriptional correlates linked to regulation of neural activity and use of an allocentric strategy. This is the first study examining transcriptomes of multiple hippocampal subregions to link age-related impairments associated with discrimination of feature overlap and alternate response strategies to gene expression in specific hippocampal subregions.
Collapse
|
7
|
Dubovyk V, Manahan-Vaughan D. Gradient of Expression of Dopamine D2 Receptors Along the Dorso-Ventral Axis of the Hippocampus. Front Synaptic Neurosci 2019; 11:28. [PMID: 31680927 PMCID: PMC6803426 DOI: 10.3389/fnsyn.2019.00028] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 09/24/2019] [Indexed: 01/11/2023] Open
Abstract
Dopamine D2-like receptors (D2R) play an important role in the regulation of hippocampal neuronal excitability and contribute to the regulation of synaptic plasticity, the encoding of hippocampus-dependent memories and the regulation of affective state. In line with this, D2R are targeted in the treatment of psychosis and affective disorders. It has been proposed that the dorso-ventral axis of the hippocampus can be functionally delineated into the dorsal pole that predominantly processes spatial information and the ventral pole that mainly addresses hippocampal processing of emotional and affective state. Although dopaminergic control of hippocampal information processing has been the focus of a multitude of studies, very little is known about the precise distribution of D2R both within anatomically defined sublayers of the hippocampus and along its dorsoventral axis, that could in turn yield insights as to the functional significance of this receptor in supporting hippocampal processing of spatial and affective information. Here, we used an immunohistochemical approach to precisely scrutinize the protein expression of D2R both within the cellular and dendritic layers of the hippocampal subfields, and along the dorso-ventral hippocampal axis. In general, we detected significantly higher levels of protein expression of D2R in the ventral, compared to the dorsal poles with regard to the CA1, CA2, CA3 and dentate gyrus (DG) regions. Effects were very consistent: the molecular layer, granule cell layer and polymorphic layer of the DG exhibited higher D2R levels in the ventral compared to dorsal hippocampus. D2R levels were also significantly higher in the ventral Stratum oriens, Stratum radiatum, and Stratum lacunosum-moleculare layers of the CA1 and CA3 regions. The apical dendrites of the ventral CA2 region also exhibited higher D2R expression compared to the dorsal pole. Taken together, our study suggests that the higher D2R expression levels of the ventral hippocampus may contribute to reported gradients in the degree of expression of synaptic plasticity along the dorso-ventral hippocampal axis, and may support behavioral information processing by the ventral hippocampus.
Collapse
Affiliation(s)
- Valentyna Dubovyk
- Medical Faculty, Department of Neurophysiology, Ruhr University Bochum, Bochum, Germany.,International Graduate School of Neuroscience, Ruhr University Bochum, Bochum, Germany
| | | |
Collapse
|
8
|
Giordano N, Iemolo A, Mancini M, Cacace F, De Risi M, Latagliata EC, Ghiglieri V, Bellenchi GC, Puglisi-Allegra S, Calabresi P, Picconi B, De Leonibus E. Motor learning and metaplasticity in striatal neurons: relevance for Parkinson's disease. Brain 2019; 141:505-520. [PMID: 29281030 DOI: 10.1093/brain/awx351] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Accepted: 10/29/2017] [Indexed: 01/08/2023] Open
Abstract
Nigro-striatal dopamine transmission is central to a wide range of neuronal functions, including skill learning, which is disrupted in several pathologies such as Parkinson's disease. The synaptic plasticity mechanisms, by which initial motor learning is stored for long time periods in striatal neurons, to then be gradually optimized upon subsequent training, remain unexplored. Addressing this issue is crucial to identify the synaptic and molecular mechanisms involved in striatal-dependent learning impairment in Parkinson's disease. In this study, we took advantage of interindividual differences between outbred rodents in reaching plateau performance in the rotarod incremental motor learning protocol, to study striatal synaptic plasticity ex vivo. We then assessed how this process is modulated by dopamine receptors and the dopamine active transporter, and whether it is impaired by overexpression of human α-synuclein in the mesencephalon; the latter is a progressive animal model of Parkinson's disease. We found that the initial acquisition of motor learning induced a dopamine active transporter and D1 receptors mediated long-term potentiation, under a protocol of long-term depression in striatal medium spiny neurons. This effect disappeared in animals reaching performance plateau. Overexpression of human α-synuclein reduced striatal dopamine active transporter levels, impaired motor learning, and prevented the learning-induced long-term potentiation, before the appearance of dopamine neuronal loss. Our findings provide evidence of a reorganization of cellular plasticity within the dorsolateral striatum that is mediated by dopamine receptors and dopamine active transporter during the acquisition of a skill. This newly identified mechanism of cellular memory is a form of metaplasticity that is disrupted in the early stage of synucleinopathies, such as Parkinson's disease, and that might be relevant for other striatal pathologies, such as drug abuse.
Collapse
Affiliation(s)
- Nadia Giordano
- Institute of Genetics and Biophysics (IGB), National Research Council, Naples, Italy.,Telethon Institute of Genetics and Medicine, Telethon Foundation, Pozzuoli, Italy
| | - Attilio Iemolo
- Institute of Genetics and Biophysics (IGB), National Research Council, Naples, Italy
| | - Maria Mancini
- Laboratory of Neurophysiology, Santa Lucia Foundation, IRCCS, Rome, Italy
| | - Fabrizio Cacace
- Laboratory of Neurophysiology, Santa Lucia Foundation, IRCCS, Rome, Italy
| | - Maria De Risi
- Institute of Genetics and Biophysics (IGB), National Research Council, Naples, Italy.,Telethon Institute of Genetics and Medicine, Telethon Foundation, Pozzuoli, Italy
| | - Emanuele Claudio Latagliata
- Laboratory of Neurophysiology, Santa Lucia Foundation, IRCCS, Rome, Italy.,Department of Psychology, University of Rome La Sapienza, Rome, Italy
| | - Veronica Ghiglieri
- Laboratory of Neurophysiology, Santa Lucia Foundation, IRCCS, Rome, Italy.,Department of Philosophy, Human, Social and Educational Sciences, University of Perugia, Perugia, Italy
| | - Gian Carlo Bellenchi
- Institute of Genetics and Biophysics (IGB), National Research Council, Naples, Italy
| | - Stefano Puglisi-Allegra
- Laboratory of Neurophysiology, Santa Lucia Foundation, IRCCS, Rome, Italy.,Department of Psychology, University of Rome La Sapienza, Rome, Italy
| | - Paolo Calabresi
- Laboratory of Neurophysiology, Santa Lucia Foundation, IRCCS, Rome, Italy.,Department of Medicine, Neurology Unit, University of Perugia, S. Andrea delle Fratte, Perugia, Italy
| | - Barbara Picconi
- Laboratory of Neurophysiology, Santa Lucia Foundation, IRCCS, Rome, Italy
| | - Elvira De Leonibus
- Institute of Genetics and Biophysics (IGB), National Research Council, Naples, Italy.,Telethon Institute of Genetics and Medicine, Telethon Foundation, Pozzuoli, Italy
| |
Collapse
|
9
|
Nguyen PV, Gelinas JN. Noradrenergic gating of long-lasting synaptic potentiation in the hippocampus: from neurobiology to translational biomedicine. J Neurogenet 2018; 32:171-182. [DOI: 10.1080/01677063.2018.1497630] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Peter V. Nguyen
- Department of Physiology and Institute of Neuroscience & Mental Health, University of Alberta School of Medicine, Edmonton, Canada
| | - Jennifer N. Gelinas
- Department of Neurology and Institute for Genomic Medicine, College of Physicians & Surgeons of Columbia University, New York, NY,USA
| |
Collapse
|
10
|
Altered function of neuronal L-type calcium channels in ageing and neuroinflammation: Implications in age-related synaptic dysfunction and cognitive decline. Ageing Res Rev 2018; 42:86-99. [PMID: 29339150 DOI: 10.1016/j.arr.2018.01.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 01/10/2018] [Accepted: 01/11/2018] [Indexed: 12/29/2022]
Abstract
The rapid developments in science have led to an increase in human life expectancy and thus, ageing and age-related disorders/diseases have become one of the greatest concerns in the 21st century. Cognitive abilities tend to decline as we get older. This age-related cognitive decline is mainly attributed to aberrant changes in synaptic plasticity and neuronal connections. Recent studies show that alterations in Ca2+ homeostasis underlie the increased vulnerability of neurons to age-related processes like cognitive decline and synaptic dysfunctions. Dysregulation of Ca2+ can lead to dramatic changes in neuronal functions. We discuss in this review, the recent advances on the potential role of dysregulated Ca2+ homeostasis through altered function of L-type voltage gated Ca2+ channels (LTCC) in ageing, with an emphasis on cognitive decline. This review therefore focuses on age-related changes mainly in the hippocampus, and with mention of other brain areas, that are important for learning and memory. This review also highlights age-related memory deficits via synaptic alterations and neuroinflammation. An understanding of these mechanisms will help us formulate strategies to reverse or ameliorate age-related disorders like cognitive decline.
Collapse
|