1
|
Uchida S, Kagitani F. Influence of age on nicotinic cholinergic regulation of blood flow in rat's olfactory bulb and neocortex. J Physiol Sci 2024; 74:18. [PMID: 38491428 PMCID: PMC10941616 DOI: 10.1186/s12576-024-00913-8] [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: 02/23/2024] [Accepted: 03/06/2024] [Indexed: 03/18/2024]
Abstract
The olfactory bulb receives cholinergic basal forebrain inputs as does the neocortex. With a focus on nicotinic acetylcholine receptors (nAChRs), this review article provides an overview and discussion of the following findings: (1) the nAChRs-mediated regulation of regional blood flow in the neocortex and olfactory bulb, (2) the nAChR subtypes that mediate their responses, and (3) their activity in old rats. The activation of the α4β2-like subtype of nAChRs produces vasodilation in the neocortex, and potentiates olfactory bulb vasodilation induced by olfactory stimulation. The nAChR activity producing neocortical vasodilation was similarly maintained in 2-year-old rats as in adult rats, but was clearly reduced in 3-year-old rats. In contrast, nAChR activity in the olfactory bulb was reduced already in 2-year-old rats. Thus, age-related impairment of α4β2-like nAChR function may occur earlier in the olfactory bulb than in the neocortex. Given the findings, the vasodilation induced by α4β2-like nAChR activation may be beneficial for neuroprotection in the neocortex and the olfactory bulb.
Collapse
Affiliation(s)
- Sae Uchida
- Department of Autonomic Neuroscience, Tokyo Metropolitan Institute for Geriatrics and Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo, 173-0015, Japan.
| | - Fusako Kagitani
- Department of Autonomic Neuroscience, Tokyo Metropolitan Institute for Geriatrics and Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo, 173-0015, Japan
| |
Collapse
|
2
|
Uchida S, Moriya J, Morihara D, Kagitani F. Nicotinic cholinergic regulation of olfactory bulb blood flow response in aged rats. J Physiol Sci 2023; 73:1. [PMID: 36864389 DOI: 10.1186/s12576-022-00859-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 12/18/2022] [Indexed: 03/04/2023]
Abstract
In our previous research, we had demonstrated the crucial role of neuronal nicotinic acetylcholine receptors (nAChRs) in potentiation of the olfactory bulb blood flow response to olfactory stimulation in adult rats. The present study examined the effects of nAChR activation on the olfactory bulb blood flow response in rats aged 24-27 months. We found that, under urethane anesthesia, unilateral olfactory nerve stimulation (300 μA, 20 Hz, 5 s) increased blood flow within the ipsilateral olfactory bulb, without changes in the systemic arterial pressure. The increase in blood flow was dependent upon the current and frequency of the stimulus. Intravenous administration of nicotine (30 μg/kg) had little effect on the olfactory bulb blood flow response to nerve stimulation at either 2 Hz or 20 Hz. These results suggest a reduction in nAChR-mediated potentiation of the olfactory bulb blood flow response in aged rats.
Collapse
Affiliation(s)
- Sae Uchida
- Department of Autonomic Neuroscience, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-Ku, Tokyo, 173-0015, Japan.
| | - Jura Moriya
- Department of Autonomic Neuroscience, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-Ku, Tokyo, 173-0015, Japan.,Division of Applied Biological Chemistry, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Daichi Morihara
- Department of Autonomic Neuroscience, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-Ku, Tokyo, 173-0015, Japan.,Department of Applied Biological Science, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Fusako Kagitani
- Department of Autonomic Neuroscience, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-Ku, Tokyo, 173-0015, Japan
| |
Collapse
|
3
|
Proteomic Signature and mRNA Expression in Hippocampus of SAMP8 and SAMR1 Mice during Aging. Int J Mol Sci 2022; 23:ijms232315097. [PMID: 36499421 PMCID: PMC9740614 DOI: 10.3390/ijms232315097] [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: 11/03/2022] [Revised: 11/27/2022] [Accepted: 11/29/2022] [Indexed: 12/03/2022] Open
Abstract
Aging is a complex process often accompanied by cognitive decline that represents a risk factor for many neurodegenerative disorders including Alzheimer's and Parkinson's disease. The molecular mechanisms involved in age-related cognitive decline are not yet fully understood, although increased neuroinflammation is considered to play a significant role. In this study, we characterized a proteomic view of the hippocampus of the senescence-accelerated mouse prone-8 (SAMP8), a model of enhanced senescence, in comparison with the senescence-accelerated-resistant mouse (SAMR1), a model of normal aging. We additionally investigated inflammatory cytokines and cholinergic components gene expression during aging in the mouse brain tissues. Proteomic data defined the expression of key proteins involved in metabolic and cellular processes in neuronal and glial cells of the hippocampus. Gene Ontology revealed that most of the differentially expressed proteins are involved in the cytoskeleton and cell motility regulation. Molecular analysis results showed that both inflammatory cytokines and cholinergic components are differentially expressed during aging, with a downward trend of cholinergic receptors and esterase enzymes expression, in contrast to an upward trend of inflammatory cytokines in the hippocampus of SAMP8. Together, our results support the important role of the cholinergic and cytokine systems in the aging of the murine brain.
Collapse
|
4
|
Gasiorowska A, Wydrych M, Drapich P, Zadrozny M, Steczkowska M, Niewiadomski W, Niewiadomska G. The Biology and Pathobiology of Glutamatergic, Cholinergic, and Dopaminergic Signaling in the Aging Brain. Front Aging Neurosci 2021; 13:654931. [PMID: 34326765 PMCID: PMC8315271 DOI: 10.3389/fnagi.2021.654931] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 06/14/2021] [Indexed: 12/12/2022] Open
Abstract
The elderly population is growing worldwide, with important health and socioeconomic implications. Clinical and experimental studies on aging have uncovered numerous changes in the brain, such as decreased neurogenesis, increased synaptic defects, greater metabolic stress, and enhanced inflammation. These changes are associated with cognitive decline and neurobehavioral deficits. Although aging is not a disease, it is a significant risk factor for functional worsening, affective impairment, disease exaggeration, dementia, and general disease susceptibility. Conversely, life events related to mental stress and trauma can also lead to accelerated age-associated disorders and dementia. Here, we review human studies and studies on mice and rats, such as those modeling human neurodegenerative diseases, that have helped elucidate (1) the dynamics and mechanisms underlying the biological and pathological aging of the main projecting systems in the brain (glutamatergic, cholinergic, and dopaminergic) and (2) the effect of defective glutamatergic, cholinergic, and dopaminergic projection on disabilities associated with aging and neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases. Detailed knowledge of the mechanisms of age-related diseases can be an important element in the development of effective ways of treatment. In this context, we briefly analyze which adverse changes associated with neurodegenerative diseases in the cholinergic, glutaminergic and dopaminergic systems could be targeted by therapeutic strategies developed as a result of our better understanding of these damaging mechanisms.
Collapse
Affiliation(s)
- Anna Gasiorowska
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Malgorzata Wydrych
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Patrycja Drapich
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Maciej Zadrozny
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Marta Steczkowska
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Wiktor Niewiadomski
- Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
| | - Grazyna Niewiadomska
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| |
Collapse
|
5
|
Panagiotou M, Michel S, Meijer JH, Deboer T. The aging brain: sleep, the circadian clock and exercise. Biochem Pharmacol 2021; 191:114563. [PMID: 33857490 DOI: 10.1016/j.bcp.2021.114563] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 04/06/2021] [Accepted: 04/07/2021] [Indexed: 12/26/2022]
Abstract
Aging is a multifactorial process likely stemming from damage accumulation and/or a decline in maintenance and repair mechanisms in the organisms that eventually determine their lifespan. In our review, we focus on the morphological and functional alterations that the aging brain undergoes affecting sleep and the circadian clock in both human and rodent models. Although both species share mammalian features, differences have been identified on several experimental levels, which we outline in this review. Additionally, we delineate some challenges on the preferred analysis and we suggest that a uniform route is followed so that findings can be smoothly compared. We conclude by discussing potential interventions and highlight the influence of physical exercise as a beneficial lifestyle intervention, and its effect on healthy aging and longevity. We emphasize that even moderate age-matched exercise is able to ameliorate several aging characteristics as far as sleep and circadian rhythms are concerned, independent of the species studied.
Collapse
Affiliation(s)
- M Panagiotou
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, The Netherlands.
| | - S Michel
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, The Netherlands
| | - J H Meijer
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, The Netherlands
| | - T Deboer
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, The Netherlands
| |
Collapse
|
6
|
Hirano T, Miyata Y, Kubo S, Ohno S, Onaru K, Maeda M, Kitauchi S, Nishi M, Tabuchi Y, Ikenaka Y, Ichise T, Nakayama SMM, Ishizuka M, Arizono K, Takahashi K, Kato K, Mantani Y, Yokoyama T, Hoshi N. Aging-related changes in the sensitivity of behavioral effects of the neonicotinoid pesticide clothianidin in male mice. Toxicol Lett 2021; 342:95-103. [PMID: 33609686 DOI: 10.1016/j.toxlet.2021.02.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 01/21/2021] [Accepted: 02/14/2021] [Indexed: 01/05/2023]
Abstract
Neonicotinoids, which act as agonists of the nicotinic acetylcholine receptors of insects, are widely used pesticides worldwide. Although epidemiological studies revealed that the detection amounts of neonicotinoids in urine are higher in the elderly population than other age-groups, there is no available information regarding the risks of neonicotinoids to older mammals. This study was aimed to investigate aging-related differences in the behavioral effects of the neonicotinoid pesticide clothianidin (CLO). We acutely administered a sub-NOAEL level (5 mg/kg) of CLO to adult (12-week-old) and aging (90-week-old) mice and conducted four behavioral tests focusing on the emotional behavior. In addition, we measured the concentrations of CLO and its metabolites in blood, brain and urine. There were age-related changes in most parameters in all behavioral tests, and CLO significantly decreased the locomotor activity in the open field test and elevated plus-maze test in the aging group, but not in the adult group. The concentrations of most CLO and its metabolites were significantly higher in the blood and brain and were slightly lower in the urine in the aging group compared to the adult group. These findings should contribute to our understanding of age-related differences in the adverse effects of neonicotinoids in mammals.
Collapse
Affiliation(s)
- Tetsushi Hirano
- Life Science Research Center, University of Toyama, 2630 Sugitani, Toyama, Toyama, 930-0194, Japan.
| | - Yuka Miyata
- Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, 657-8501, Japan
| | - Shizuka Kubo
- Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, 657-8501, Japan
| | - Shuji Ohno
- Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, 657-8501, Japan
| | - Kanoko Onaru
- Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, 657-8501, Japan
| | - Mizuki Maeda
- Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, 657-8501, Japan
| | - Sayaka Kitauchi
- Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, 657-8501, Japan
| | - Misaki Nishi
- Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, 657-8501, Japan
| | - Yoshiaki Tabuchi
- Life Science Research Center, University of Toyama, 2630 Sugitani, Toyama, Toyama, 930-0194, Japan
| | - Yoshinori Ikenaka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido 060-0818, Japan; Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - Takahiro Ichise
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido 060-0818, Japan
| | - Shouta M M Nakayama
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido 060-0818, Japan
| | - Mayumi Ishizuka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido 060-0818, Japan
| | - Koji Arizono
- Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, 3 Chome-1-100 Tsukide, Higashi Ward, Kumamoto, 862-8502, Japan
| | - Keisuke Takahashi
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba, 274-8510, Japan
| | - Keisuke Kato
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi, Chiba, 274-8510, Japan
| | - Youhei Mantani
- Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, 657-8501, Japan
| | - Toshifumi Yokoyama
- Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, 657-8501, Japan
| | - Nobuhiko Hoshi
- Department of Animal Science, Graduate School of Agricultural Science, Kobe University, Kobe, Hyogo, 657-8501, Japan
| |
Collapse
|
7
|
Gamage R, Wagnon I, Rossetti I, Childs R, Niedermayer G, Chesworth R, Gyengesi E. Cholinergic Modulation of Glial Function During Aging and Chronic Neuroinflammation. Front Cell Neurosci 2020; 14:577912. [PMID: 33192323 PMCID: PMC7594524 DOI: 10.3389/fncel.2020.577912] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/07/2020] [Indexed: 12/12/2022] Open
Abstract
Aging is a complex biological process that increases the risk of age-related cognitive degenerative diseases such as dementia, including Alzheimer’s disease (AD), Lewy Body Dementia (LBD), and mild cognitive impairment (MCI). Even non-pathological aging of the brain can involve chronic oxidative and inflammatory stress, which disrupts the communication and balance between the brain and the immune system. There has been an increasingly strong connection found between chronic neuroinflammation and impaired memory, especially in AD. While microglia and astrocytes, the resident immune cells of the central nervous system (CNS), exerting beneficial effects during the acute inflammatory phase, during chronic neuroinflammation they can become more detrimental. Central cholinergic circuits are involved in maintaining normal cognitive function and regulating signaling within the entire cerebral cortex. While neuronal-glial cholinergic signaling is anti-inflammatory and anti-oxidative, central cholinergic neuronal degeneration is implicated in impaired learning, memory sleep regulation, and attention. Although there is evidence of cholinergic involvement in memory, fewer studies have linked the cholinergic anti-inflammatory and anti-oxidant pathways to memory processes during development, normal aging, and disease states. This review will summarize the current knowledge of cholinergic effects on microglia and astroglia, and their role in both anti-inflammatory and anti-oxidant mechanisms, concerning normal aging and chronic neuroinflammation. We provided details on how stimulation of α7 nicotinic acetylcholine (α7nACh) receptors can be neuroprotective by increasing amyloid-β phagocytosis, decreasing inflammation and reducing oxidative stress by promoting the nuclear factor erythroid 2-related factor 2 (Nrf2) pathways and decreasing the release of pro-inflammatory cytokines. There is also evidence for astroglial α7nACh receptor stimulation mediating anti-inflammatory and antioxidant effects by inhibiting the nuclear factor-κB (NF-κB) pathway and activating the Nrf2 pathway respectively. We conclude that targeting cholinergic glial interactions between neurons and glial cells via α7nACh receptors could regulate neuroinflammation and oxidative stress, relevant to the treatment of several neurodegenerative diseases.
Collapse
Affiliation(s)
- Rashmi Gamage
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Ingrid Wagnon
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Ilaria Rossetti
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Ryan Childs
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Garry Niedermayer
- School of Science, Western Sydney University, Penrith, NSW, Australia
| | - Rose Chesworth
- School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Erika Gyengesi
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| |
Collapse
|
8
|
Utkin YN. Aging Affects Nicotinic Acetylcholine Receptors in Brain. Cent Nerv Syst Agents Med Chem 2019; 19:119-124. [PMID: 30894113 DOI: 10.2174/1871524919666190320102834] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 02/28/2019] [Accepted: 03/08/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Aging is a common and inevitable stage in the life cycle of higher organisms. Different organs, including the central nervous system, are affected by aging in different ways. Many processes are involved in aging, and neurodegeneration is one of the aging processes in which the central nervous system is engaged. Brain degeneration during normal aging underlies cognitive disorders experienced by older people. Not all molecular mechanisms associated with age-related neurodegeneration are fully understood; however, there is a whole range of data on the participation of nicotinic acetylcholine receptors in the processes of aging and neurodegeneration. Two main subtypes of nicotinic acetylcholine receptor α7 and α4β2 present in the central nervous system are affected by these processes. The loss of these receptor subtypes during normal aging is one of the reasons for the cognitive impairments. The decrease in nicotinic acetylcholine receptors is also very important for the pathogenesis of age-related neurodegenerative diseases. Thus, the drugs enhancing receptor functions may be considered promising for the treatment of cognitive dysfunction in the aged people. CONCLUSION To achieve healthy longevity, the molecular processes that occur during aging should be established. In this regard, the participation and role of nicotinic acetylcholine receptors in the brain aging and degeneration are considered in this review.
Collapse
Affiliation(s)
- Yuri N Utkin
- Laboratory of Molecular Toxinology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russian Federation
- National University of Science and Technology MISIS, 119049 Moscow, Russian Federation
| |
Collapse
|
9
|
da Costa Lima MS, Hartkopf ACL, de Souza Tsujisaki RA, Oshiro ET, Shapiro JT, de Fatima Cepa Matos M, Cavalheiros Dorval ME. Isolation and molecular characterization of Leishmania infantum in urine from patients with visceral leishmaniasis in Brazil. Acta Trop 2018; 178:248-251. [PMID: 29221850 DOI: 10.1016/j.actatropica.2017.12.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 11/20/2017] [Accepted: 12/04/2017] [Indexed: 10/18/2022]
Abstract
Leishmania infantum is a protozoan that causes visceral leishmaniasis, a potentially deadly neglected tropical disease. The gold standard for diagnosis has traditionally been detection of amastigotes in bone marrow or spleen aspirates, but this is an invasive procedure that carries the risk of serious complications. Newer PCR techniques are opening new avenues and tissues for testing. Therefore, we tested if amastigotes and DNA from L. infantum could be detected in patient urine. We detected L. infantum DNA in six out of 30 urine samples from patients with visceral leishmaniasis and the promastigotes were isolated in culture from the urine of one patient. These results suggest the feasibility of using urine samples to diagnose visceral leishmaniasis, especially in acute cases or renal infection, providing a valuable tool for doctors and clinicians to use for screening and diagnosis of leishmaniasis in patients.
Collapse
|
10
|
Ahmed T, Zahid S, Mahboob A, Farhat SM. Cholinergic System and Post-translational Modifications: An Insight on the Role in Alzheimer's Disease. Curr Neuropharmacol 2017; 15:480-494. [PMID: 27012953 PMCID: PMC5543671 DOI: 10.2174/1570159x14666160325121145] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 12/02/2015] [Accepted: 03/03/2016] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is the most common form of old age dementia. The formation of amyloid plaques (Aβ), neurofibrillary tangles and loss of basal forebrain cholinergic neurons are the hallmark events in the pathology of AD. LITERATURE REVIEW Cholinergic system is one of the most important neurotransmitter system involved in learning and memory which preferentially degenerates in the initial stages of AD. Activation of cholinergic receptors (muscarinic and nicotinic) activates multiple pathways which result in post translational modifications (PTMs) in multiple proteins which bring changes in nervous system. Cholinergic receptors-mediated PTMs "in-part" substantially affect the biosynthesis, proteolysis, degradation and expression of many proteins and in particular, amyloid precursor protein (APP). APP is subjected to several PTMs (proteolytic processing, glycosylation, sulfation, and phosphorylation) during its course of processing, resulting in Aβ deposition, leading to AD. Aβ also alters the PTMs of tau which is a microtubule associated protein. Therefore, post-translationally modified tau and Aβ collectively aggravate the neuronal loss that leads to cholinergic hypofunction. CONCLUSION Despite the accumulating evidences, the interaction between cholinergic neurotransmission and the physiological significance of PTM events remain speculative and still needs further exploration. This review focuses on the role of cholinergic system and discusses the significance of PTMs in pathological progression of AD and highlights some important future directions.
Collapse
Affiliation(s)
- Touqeer Ahmed
- Neurobiology Laboratory, Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Sector H-12, Islamabad, 44000, Pakistan
| | - Saadia Zahid
- Neurobiology Laboratory, Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Sector H-12, Islamabad, 44000, Pakistan
| | | | | |
Collapse
|
11
|
Sharma S, Nag TC, Thakar A, Bhardwaj DN, Roy TS. The aging human cochlear nucleus: Changes in the glial fibrillary acidic protein, intracellular calcium regulatory proteins, GABA neurotransmitter and cholinergic receptor. J Chem Neuroanat 2014; 56:1-12. [DOI: 10.1016/j.jchemneu.2013.12.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Revised: 12/19/2013] [Accepted: 12/19/2013] [Indexed: 01/23/2023]
|
12
|
Reinvang I, Espeseth T, Westlye LT. APOE-related biomarker profiles in non-pathological aging and early phases of Alzheimer's disease. Neurosci Biobehav Rev 2013; 37:1322-35. [DOI: 10.1016/j.neubiorev.2013.05.006] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 04/10/2013] [Accepted: 05/10/2013] [Indexed: 02/01/2023]
|
13
|
Ferreira EC, Gontijo CM, Cruz I, Melo MN, Silva AM. Alternative PCR protocol using a single primer set for assessing DNA quality in several tissues from a large variety of mammalian species living in areas endemic for leishmaniasis. Mem Inst Oswaldo Cruz 2011; 105:895-8. [PMID: 21120359 DOI: 10.1590/s0074-02762010000700009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Accepted: 08/12/2010] [Indexed: 11/22/2022] Open
Abstract
The aim of this work was to establish a modified pre-diagnostic polymerase chain reaction (PCR) protocol using a single primer set that enables successful amplification of a highly conserved mammalian sequence in order to determine overall sample DNA quality for multiple mammalian species that inhabit areas endemic for leishmaniasis. The gene encoding interphotoreceptor retinoid-binding protein (IRBP), but not other conserved genes, was efficiently amplified in DNA samples from tail skin, ear skin, bone marrow, liver and spleen from all of the species tested. In tissue samples that were PCR-positive for Leishmania, we found that DNA from 100%, 55% and 22% of the samples tested resulted in a positive PCR reaction for the IRBP, beta-actin and beta-globin genes, respectively. Nucleotide sequencing of an IRBP amplicon resolved any questions regarding the taxonomical classification of a rodent, which was previously based simply on the morphological features of the animal. Therefore, PCR amplification and analysis of the IRBP amplicon are suitable for pre-diagnostically assessing DNA quality and identifying mammalian species living in areas endemic to leishmaniasis and other diseases.
Collapse
|
14
|
Abstract
The world population is becoming older now. The boom of the elderly population comes from public health efforts to improve living conditions and prevent disease, and from improved medical interventions. People more than 65-year-old who are representing 12.9% of the population now is expected to grow to be 19% of the population by 2030. Very few numbers of diseases will have such socioeconomic burden on society in the newer world. Although Alzheimer's disease (AD) has been studied very well recently, still its exact etiopathogenesis is unknown. Currently there are no available tests for the definitive diagnosis of AD. So the clinical diagnosis of AD remains a diagnosis of exclusion. This limits the potential for early intervention. The difference between normal degenerative processes of brain and preclinical changes of AD is a gray zone and there is no particular way to distinguish between the two. Now several modalities like functional magnetic resonance imaging (fMRI), positron emission tomography (PET) scan, electrophysiological tests and cerebrospinal fluid (CSF) biomarkers for tauopathy and Aβ have shown to be promising in the development of early diagnostic tools for neurodegenerative changes and help us to differentiate between healthy aging and pathological aging. In this article we tried to discuss about the differences between pathological and physiological aging process from radiological, pathological, biochemical, and electrophysiological point of view. However, differentiating between physiological and pathological dementia still remains a challenge.
Collapse
Affiliation(s)
- Krishnendu Ghosh
- Department of Psychiatry and Behavioral Sciences, Von Tauber Institute for Global Psychiatry, Nassau University Medical Center, NY, USA
| | - Pratibha Agarwal
- Department of Psychiatry and Behavioral Sciences, Von Tauber Institute for Global Psychiatry, Nassau University Medical Center, NY, USA
| | - Greg Haggerty
- Department of Psychiatry and Behavioral Sciences, Von Tauber Institute for Global Psychiatry, Nassau University Medical Center, NY, USA
| |
Collapse
|
15
|
Reinvang I, Deary IJ, Fjell AM, Steen VM, Espeseth T, Parasuraman R. Neurogenetic effects on cognition in aging brains: a window of opportunity for intervention? Front Aging Neurosci 2010; 2:143. [PMID: 21103005 PMCID: PMC2987509 DOI: 10.3389/fnagi.2010.00143] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Accepted: 09/17/2010] [Indexed: 12/15/2022] Open
Abstract
Knowledge of genetic influences on cognitive aging can constrain and guide interventions aimed at limiting age-related cognitive decline in older adults. Progress in understanding the neural basis of cognitive aging also requires a better understanding of the neurogenetics of cognition. This selective review article describes studies aimed at deriving specific neurogenetic information from three parallel and interrelated phenotype-based approaches: psychometric constructs, cognitive neuroscience-based processing measures, and brain imaging morphometric data. Developments in newer genetic analysis tools, including genome wide association, are also described. In particular, we focus on models for establishing genotype-phenotype associations within an explanatory framework linking molecular, brain, and cognitive levels of analysis. Such multiple-phenotype approaches indicate that individual variation in genes central to maintaining synaptic integrity, neurotransmitter function, and synaptic plasticity are important in affecting age-related changes in brain structure and cognition. Investigating phenotypes at multiple levels is recommended as a means to advance understanding of the neural impact of genetic variants relevant to cognitive aging. Further knowledge regarding the mechanisms of interaction between genetic and preventative procedures will in turn help in understanding the ameliorative effect of various experiential and lifestyle factors on age-related cognitive decline.
Collapse
Affiliation(s)
- Ivar Reinvang
- Department of Psychology, University of OsloOslo, Norway
| | - Ian J. Deary
- Department of Psychology, University of EdinburghEdinburgh, UK
| | | | - Vidar M. Steen
- Department of Clinical Medicine, University of BergenBergen, Norway
- Center for Medical Genetics and Molecular Medicine, Haukeland University HospitalBergen, Norway
| | | | - Raja Parasuraman
- Department of Psychology, George Mason UniversityFairfax, VA, USA
| |
Collapse
|
16
|
Epistasis between APOE and nicotinic receptor gene CHRNA4 in age related cognitive function and decline. J Int Neuropsychol Soc 2010; 16:424-32. [PMID: 20331911 DOI: 10.1017/s1355617710000263] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Healthy participants (n = 237) aged 45-79 were tested neuropsychologically with tests of memory, speed, and cognitive control and followed up for 3-5 years (mean, 3.4 years). The sample was genotyped for apolipoprotein E (APOE) and CHolinergic Receptor for Nicotine Alpha 4 (CHRNA4), and genetic effects on cognitive function at initial testing and on cognitive decline was studied. We predicted relatively stronger effects of APOE on memory, and of CHRNA4 on speeded tasks. The predictions were partially confirmed, but we found interactive effects of APOE and CHRNA4 in several cognitive domains. Being an APOE epsilon4/CHRNA4 TT carrier was associated with slower and less efficient performance, and with steeper decline in speed tasks and in delayed recall. Age dependent genetic effects were found for both APOE and CHRNA4, where old participants (60-79 years) showed a negative influence of TT carrier status on initial memory performance, but a tendency for steeper memory decline in epsilon4 carriers. Inconsistent and small effects of APOE reported in previous studies of healthy groups may be caused by failure to consider epistasis of APOE with nicotinic receptor and other genes.
Collapse
|
17
|
Localisation of pre- and postsynaptic cholinergic markers in the human brain. Behav Brain Res 2010; 221:341-55. [PMID: 20170687 DOI: 10.1016/j.bbr.2010.02.025] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Accepted: 02/10/2010] [Indexed: 12/20/2022]
Abstract
The cholinergic neurotransmission in the central nervous system plays an important role in modulating cognitive processes such as learning, memory, arousal and sleep as well as in modulating locomotor activity. Dysfunction of the central cholinergic system is involved in numerous neuropsychiatric diseases. This review will provide a synopsis on the regional localisation of cholinergic and cholinoceptive structures within the adult human brain. On the cholinergic site data based on the distribution of choline acetyltransferase-immunoreactive structures are in the focus, complemented by data from acetylcholinesterase and vesicular acetylcholine transporter studies. On the cholinoceptive site, the distribution and localisation of receptors that transduce the acetylcholine message, i.e. the muscarinic and the nicotinic acetylcholine receptors is summarized. In addition to these data obtained on post mortem brain an overview of markers which allow for the in vivo monitoring of the cholinergic system in the brain is given. The detailed knowledge on the distribution and localisation of cholinergic markers in human brain will provide further information on the cholinergic circuits of neurotransmission - a prerequisite for the interpretation of in vivo imaging data and the development of selective diagnostic and therapeutic compounds.
Collapse
|
18
|
Bertram L. Alzheimer's disease genetics current status and future perspectives. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2009; 84:167-84. [PMID: 19501718 DOI: 10.1016/s0074-7742(09)00409-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is a genetically complex disease whose pathogenesis is largely influenced by genetic factors. Three decades of intensive research have yielded four established AD genes (APP, PSEN1, PSEN2, APOE), and hundreds of potential susceptibility loci, none of which has been unequivocally shown to modify disease risk using conventional methodologies. The results of genome-wide association studies (GWAS) are now adding to an already vast and complicated body of data. To facilitate the evaluation and interpretation of these findings, we have recently created a database for genetic association studies in AD ("AlzGene"; available at http://www.alzgene.org). In addition to systematically screening and summarizing the scientific literature for eligible studies, AlzGene provides the results of allele-based meta-analyses for all polymorphisms with sufficient genotype data. Currently, these meta-analyses highlight over 20 different potential AD genes, several of which were originally implicated by a GWAS. First follow-up analyses in a large collection of over 1300 AD families reveal that-in addition to APOE-genetic variants in ACE, CHRNB2, GAB2, and TF show the most consistent risk effects across a wide range of independent samples and study designs. The chapter highlights these and other promising findings from the recent AD genetics literature and provides an overview of the powerful new tools aiding researchers today to unravel the genetic underpinnings of this devastating disease.
Collapse
Affiliation(s)
- Lars Bertram
- Neuropsychiatric Genetics Group, Department of Vertebrate Genomics, Max-Planck Institute for Molecular Genetics, Berlin 14195, Germany
| |
Collapse
|
19
|
Thirty years of Alzheimer's disease genetics: the implications of systematic meta-analyses. Nat Rev Neurosci 2008; 9:768-78. [PMID: 18802446 DOI: 10.1038/nrn2494] [Citation(s) in RCA: 515] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The genetic underpinnings of Alzheimer's disease (AD) remain largely elusive despite early successes in identifying three genes that cause early-onset familial AD (those that encode amyloid precursor protein (APP) and the presenilins (PSEN1 and PSEN2)), and one genetic risk factor for late-onset AD (the gene that encodes apolipoprotein E (APOE)). A large number of studies that aimed to help uncover the remaining disease-related loci have been published in recent decades, collectively proposing or refuting the involvement of over 500 different gene candidates. Systematic meta-analyses of these studies currently highlight more than 20 loci that have modest but significant effects on AD risk. This Review discusses the putative pathogenetic roles and common biochemical pathways of some of the most genetically and biologically compelling of these potential AD risk factors.
Collapse
|
20
|
Schjeide BMM, McQueen MB, Mullin K, DiVito J, Hogan MF, Parkinson M, Hooli B, Lange C, Blacker D, Tanzi RE, Bertram L. Assessment of Alzheimer's disease case-control associations using family-based methods. Neurogenetics 2008; 10:19-25. [PMID: 18830724 DOI: 10.1007/s10048-008-0151-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Accepted: 09/03/2008] [Indexed: 11/25/2022]
Abstract
The genetics of Alzheimer's disease (AD) is heterogeneous and remains only ill-defined. We have recently created a freely available and continuously updated online database (AlzGene; http://www.alzgene.org ) for which we collect all published genetic association studies in AD and perform systematic meta-analyses on all polymorphisms with sufficient genotype data. In this study, we tested 27 genes (ACE, BDNF, CH25H, CHRNB2, CST3, CTSD, DAPK1, GALP, hCG2039140, IL1B, LMNA, LOC439999, LOC651924, MAPT, MTHFR, MYH13, PCK1, PGBD1, PRNP, PSEN1, SORCS1, SORL1, TF, TFAM, TNK1, GWA_14q32.13, and GWA_7p15.2), all showing significant association with AD risk in the AlzGene meta-analyses, in a large collection of family-based samples comprised of 4,180 subjects from over 1,300 pedigrees. Overall, we observe significant association with risk for AD and polymorphisms in ACE, CHRNB2, TF, and an as yet uncharacterized locus on chromosome 7p15.2 [rs1859849]. For all four loci, the association was observed with the same alleles as in the AlzGene meta-analyses. The convergence of case-control and family-based findings suggests that these loci currently represent the most promising AD gene candidates. Further fine-mapping and functional analyses are warranted to elucidate the potential biochemical mechanisms and epidemiological relevance of these genes.
Collapse
Affiliation(s)
- Brit-Maren M Schjeide
- MassGeneral Institute for Neurodegenerative Disease (MIND), Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Age-related decline in nicotinic receptor availability with [(123)I]5-IA-85380 SPECT. Neurobiol Aging 2008; 30:1490-7. [PMID: 18242781 DOI: 10.1016/j.neurobiolaging.2007.12.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Revised: 10/20/2007] [Accepted: 12/03/2007] [Indexed: 11/20/2022]
Abstract
Human postmortem studies have reported decreases with age in high affinity nicotine binding in brain. We investigated the effect of age on beta(2)-containing nicotinic acetylcholine receptor (beta(2)-nAChR) availability in eight brain regions of living human subjects using the ligand [(123)I]5-IA-85380 ([(123)I]5-IA) and single photon emission computed tomography (SPECT). Healthy, nonsmokers (N=47) ranging in age from 18 to 85 were administered [(123)I]5-IA using a bolus plus constant infusion paradigm and imaged 6-8h later under equilibrium conditions. The effect of age on regional beta(2)-nAChR availability (V(T), regional brain activity/free plasma parent, a measure proportional to the binding potential) was analyzed using linear regression and Pearson's correlation (r). Age and regional beta(2)-nAChR availability were inversely correlated in seven of the eight brain regions analyzed, with decline ranging from 32% (thalamus) to 18% (occipital cortex) over the adult lifespan, or up to 5% per decade. These results in living human subjects corroborate postmortem reports of decline in high affinity nicotine binding with age and may aid in elucidating the role of beta(2)-nAChRs in cognitive aging.
Collapse
|
22
|
Vasto S, Candore G, Listì F, Balistreri CR, Colonna-Romano G, Malavolta M, Lio D, Nuzzo D, Mocchegiani E, Di Bona D, Caruso C. Inflammation, genes and zinc in Alzheimer's disease. ACTA ACUST UNITED AC 2007; 58:96-105. [PMID: 18190968 DOI: 10.1016/j.brainresrev.2007.12.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2007] [Revised: 11/30/2007] [Accepted: 12/01/2007] [Indexed: 10/22/2022]
Abstract
Alzheimer's disease (AD) is a heterogeneous and progressive neurodegenerative disease which in Western society mainly accounts for clinical dementia. AD has been linked to inflammation and metal biological pathway. Neuro-pathological hallmarks are senile plaques, resulting from the accumulation of several proteins and an inflammatory reaction around deposits of amyloid, a fibrillar protein, Abeta, product of cleavage of a much larger protein, the beta-amyloid precursor protein (APP) and neurofibrillary tangles. Amyloid deposition, due to the accumulation of Abeta peptide, is the main pathogenetic mechanism. Inflammation clearly occurs in pathologically vulnerable regions of AD and several inflammatory factors influencing AD development, i.e. environmental factors (pro-inflammatory phenotype) and/or genetic factors (pro-inflammatory genotype) have been described. At the biochemical level metals such as zinc are known to accelerate the aggregation of the amyloid peptide and play a role in the control of inflammatory responses. In particular, zinc availability may regulate mRNA cytokine expression, so influencing inflammatory network phenotypic expression.
Collapse
Affiliation(s)
- Sonya Vasto
- Department of Pathobiology and Biomedical Methodology, University of Palermo, Corso Tukory, 211, 90134 Palermo, Italy
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Liu L, van Groen T, Kadish I, Tollefsbol TO. DNA methylation impacts on learning and memory in aging. Neurobiol Aging 2007; 30:549-60. [PMID: 17850924 PMCID: PMC2656583 DOI: 10.1016/j.neurobiolaging.2007.07.020] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 06/19/2007] [Accepted: 07/24/2007] [Indexed: 12/20/2022]
Abstract
Learning and memory are two of the fundamental cognitive functions that confer us the ability to accumulate knowledge from our experiences. Although we use these two mental skills continuously, understanding the molecular basis of learning and memory is very challenging. Methylation modification of DNA is an epigenetic mechanism that plays important roles in regulating gene expression, which is one of the key processes underlying the functions of cells including neurons. Interestingly, a genome-wide decline in DNA methylation occurs in the brain during normal aging, which coincides with a functional decline in learning and memory with age. It has been speculated that DNA methylation in neurons might be involved in memory coding. However, direct evidence supporting the role of DNA methylation in memory formation is still under investigation. This particular function of DNA methylation has not drawn wide attention despite several important studies that have provided supportive evidence for the epigenetic control of memory formation. To facilitate further exploration of the epigenetic basis of memory function, we will review existing studies on DNA methylation that are related to the development and function of the nervous system. We will focus on studies illustrating how DNA methylation regulates neural activities and memory formation via the control of gene expression in neurons, and relate these studies to various age-related neurological disorders that affect cognitive functions.
Collapse
Affiliation(s)
- Liang Liu
- Department of Biology, University of Alabama at Birmingham, 175 Campbell Hall, 1300 University Boulevard, Birmingham, AL 35294-1170, USA.
| | | | | | | |
Collapse
|
24
|
Bao J, Lei D, Du Y, Ohlemiller KK, Beaudet AL, Role LW. Requirement of nicotinic acetylcholine receptor subunit beta2 in the maintenance of spiral ganglion neurons during aging. J Neurosci 2006; 25:3041-5. [PMID: 15788760 PMCID: PMC2280031 DOI: 10.1523/jneurosci.5277-04.2005] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Age-related hearing loss (presbycusis) is a major health concern for the elderly. Loss of spiral ganglion neurons (SGNs), the primary sensory relay of the auditory system, is associated consistently with presbycusis. The causative molecular events responsible for age-related loss of SGNs are unknown. Recent reports directly link age-related neuronal loss in cerebral cortex with the loss of high-affinity nicotine acetylcholine receptors (nAChRs). In cochlea, cholinergic synapses are made by olivocochlear efferent fibers on the outer hair cells that express alpha9 nAChR subunits and on the peripheral projections of SGNs that express alpha2, alpha4-7, and beta2-3 nAChR subunits. A significantly decreased expression of the beta2 nAChR subunit in SGNs was found specifically in mice susceptible to presbycusis. Furthermore, mice lacking the beta2 nAChR subunit (beta2-/-), but not mice lacking the alpha5 nAChR subunit (alpha5-/-), have dramatic hearing loss and significant reduction in the number of SGNs. Our findings clearly established a requirement for beta2 nAChR subunit in the maintenance of SGNs during aging.
Collapse
MESH Headings
- Acoustic Stimulation/methods
- Age Factors
- Aging/metabolism
- Animals
- Blotting, Northern/methods
- Blotting, Western/methods
- Cadherins/genetics
- Disease Models, Animal
- Dose-Response Relationship, Radiation
- Evoked Potentials, Auditory, Brain Stem/genetics
- Gene Expression Regulation/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Mutant Strains
- Neurons/metabolism
- Presbycusis/genetics
- Presbycusis/metabolism
- Presbycusis/physiopathology
- Protein Subunits/deficiency
- Protein Subunits/genetics
- Protein Subunits/metabolism
- RNA, Messenger/metabolism
- Receptors, Nicotinic/deficiency
- Receptors, Nicotinic/genetics
- Receptors, Nicotinic/metabolism
- Receptors, Nicotinic/physiology
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Spiral Ganglion/cytology
Collapse
Affiliation(s)
- Jianxin Bao
- Department of Otolaryngology, Center for Aging, Washington University, St. Louis, Missouri 63110, USA.
| | | | | | | | | | | |
Collapse
|
25
|
Cook LJ, Ho LW, Wang L, Terrenoire E, Brayne C, Evans JG, Xuereb J, Cairns NJ, Turic D, Hollingworth P, Moore PJ, Jehu L, Archer N, Walter S, Foy C, Edmondson A, Powell J, Lovestone S, Williams J, Rubinsztein DC. Candidate gene association studies of genes involved in neuronal cholinergic transmission in Alzheimer's disease suggests choline acetyltransferase as a candidate deserving further study. Am J Med Genet B Neuropsychiatr Genet 2005; 132B:5-8. [PMID: 15690550 DOI: 10.1002/ajmg.b.30068] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Consistent deficits in the cholinergic system are evident in the brains of Alzheimer's Disease (AD) patients, including reductions in the activities of acetylcholine, acetylcholinesterase (AChE), and choline acetyltransferase (ChAT), increased butyrylcholinesterase (BChE) activity, and a selective loss of nicotinic acetylcholine receptors (nAChRs). Accordingly, we have analyzed polymorphisms in the genes encoding AChE, ChAT, BChE, and several of the subunit genes from neuronal nAChRs, for genetic associations with late-onset AD. A significant association for disease was detected for a non-coding polymorphism in ChAT (allele chi(1) (2) = 12.84, P = 0.0003; genotype chi(2) (2) = 11.89, P = 0.0026). Although replication analysis did not confirm the significance of this finding when the replication samples were considered alone (allele chi(1) (2) = 1.02, P = 0.32; genotype chi(2) (2) = 1.101, P = 0.58) the trends were in the correct direction and a significant association remained when the two sample sets were pooled (allele chi(1) (2) = 12.37, P = 0.0004; genotype chi(2) (2) = 11.61, P = 0.003). Previous studies have reported significant disease associations for both the K-variant of BChE and the coding ChAT rs3810950 polymorphism with AD. Replication analyses of these two loci failed to detect any significant association for disease in our case-control samples.
Collapse
Affiliation(s)
- Lynnette J Cook
- Department of Medical Genetics, Cambridge Institute for Medical Research, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 2XY, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Abstract
This article reviews the modulation of cognitive function by normal genetic variation. Although the heritability of "g" is well established, the genes that modulate specific cognitive functions are largely unidentified. Application of the allelic association approach to individual differences in cognition has begun to reveal the effects of single nucleotide polymorphisms on specific and general cognitive functions. This article proposes a framework for relating genotype to cognitive phenotype by considering the effect of genetic variation on the protein product of specific genes within the context of the neural basis of particular cognitive domains. Specificity of effects is considered, from genes controlling part of one receptor type to genes controlling agents of neuronal repair, and evidence is reviewed of cognitive modulation by polymorphisms in dopaminergic and cholinergic receptor genes, dopaminergic enzyme genes, and neurotrophic genes. Although allelic variation in certain genes can be reliably linked to cognition--specifically to components of attention, working memory, and executive function in healthy adults--the specificity, generality, and replicability of the effects are not fully known.
Collapse
|
27
|
Cook LJ, Ho LW, Taylor AE, Brayne C, Evans JG, Xuereb J, Cairns NJ, Pritchard A, Lemmon H, Mann D, St Clair D, Turic D, Hollingworth P, Moore PJ, Jehu L, Archer N, Walter S, Foy C, Edmondson A, Powell J, Lovestone S, Owen MJ, Williams J, Lendon C, Rubinsztein DC. Candidate gene association studies of the α4 (CHRNA4) and β2 (CHRNB2) neuronal nicotinic acetylcholine receptor subunit genes in Alzheimer's disease. Neurosci Lett 2004; 358:142-6. [PMID: 15026168 DOI: 10.1016/j.neulet.2004.01.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2003] [Revised: 01/12/2004] [Accepted: 01/12/2004] [Indexed: 11/24/2022]
Abstract
Consistent deficits in the cholinergic system are evident in Alzheimer's disease (AD) patients, including selective loss of alpha4beta2 nicotinic acetylcholine receptors in the brains of AD patients. Knockout mice for the beta2 subunit have impaired neuronal survival in ageing. Accordingly, we have analysed polymorphisms in the genes that encode the alpha4 and beta2 subunits, CHRNA4 and CHRNB2 respectively, for genetic associations with late-onset AD. A significant association for disease was observed for a non-coding polymorphism in CHRNB2 (odds ratio=0.57, 95% confidence interval=0.35-0.95, P=0.024). Replication analysis was performed in two further sample sets. While these did not individually yield significant results, a significant association remained when all samples were pooled (odds ratio=0.70, 95% confidence interval=0.52-0.95, P=0.019). These data suggest that this variant warrants further examination in large case-control series.
Collapse
Affiliation(s)
- Lynnette J Cook
- Department of Medical Genetics, Cambridge Institute for Medical Research, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2XY, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Abstract
Activation of neuronal nicotinic acetylcholine receptors (nAChRs) has been shown to maintain cognitive function following aging or the development of dementia. Nicotine and nicotinic agonists have been shown to improve cognitive function in aged or impaired subjects. Smoking has also been shown in some epidemiological studies to be protective against the development of neurodegenerative diseases. This is supported by animal studies that have shown nicotine to be neuroprotective both in vivo and in vitro. Treatment with nicotinic agonists may therefore be useful in both slowing the progression of neurodegenerative illnesses, and improving function in patients with the disease. While increased nicotinic function has been shown to be beneficial, loss of cholinergic markers is often seen in patients with dementia, suggesting that decreased cholinergic function could contribute to both the cognitive deficits, and perhaps the neuronal degeneration, associated with dementia. In this article we will review the literature on each of these areas. We will also present hypotheses that might address the mechanisms underlying the ability of nAChR function to protect against neurodegeneration or improve cognition, two potentially distinct actions of nicotine.
Collapse
Affiliation(s)
- Marina R Picciotto
- Department of Psychiatry, Yale University School of Medicine, 34 Park Street, New Haven, Connecticut 06508, USA.
| | | |
Collapse
|
29
|
Perry EK, Martin-Ruiz CM, Court JA. Nicotinic receptor subtypes in human brain related to aging and dementia. Alcohol 2001; 24:63-8. [PMID: 11522424 DOI: 10.1016/s0741-8329(01)00130-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Neuronal nicotinic receptors are attracting increasing interest, beyond their role in relation to tobacco use, in the areas of human brain aging and disorders associated with dementia. Of the different receptor subtypes in the mammalian brain, many decline with normal aging in several different areas, including particularly cerebral cortex and hippocampus. There are further select subtype changes in the two most common forms of dementia in the elderly: Alzheimer's disease and dementia with Lewy bodies. The alpha4 subunit is most extensively reduced in the cortex in Alzheimer's disease, reflected in the loss of the high affinity binding site. There are also reductions in the low affinity binding site (alpha-bungarotoxin binding) in the thalamus in both disorders, which are likely to reflect the loss of the homomeric (most commonly alpha7) receptor subtype. Correlations exist between some of these receptor abnormalities and clinical and pathological features of the diseases. Targeting such receptors is a current therapeutic objective.
Collapse
Affiliation(s)
- E K Perry
- Joint MRC-Newcastle University Centre Development in Clinical Brain Ageing, Newcastle General Hospital, Westgate Road, Newcastle upon Tyne, NE4 6BE, UK
| | | | | |
Collapse
|
30
|
Court J, Martin-Ruiz C, Piggott M, Spurden D, Griffiths M, Perry E. Nicotinic receptor abnormalities in Alzheimer's disease. Biol Psychiatry 2001; 49:175-84. [PMID: 11230868 DOI: 10.1016/s0006-3223(00)01116-1] [Citation(s) in RCA: 178] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Loss of cortical nicotinic acetylcholine receptors with high affinity for agonists (20-50%) in patients with Alzheimer's disease is a common finding. Recent immunochemical analyses indicate that this deficit is predominantly associated with the loss of alpha4 subunits (30-50%), although modest reductions of alpha3 may occur in some individuals (25-29%). No reduction of beta2 subunit protein expression or levels of alpha3 and alpha4 messenger RNA has been reported. Decline in cortical [(125)I]alpha-bungarotoxin binding and alpha7 protein expression does not appear to be as extensive or widespread as the loss of alpha4 (0-40%), with no reduction in messenger RNA expression. In the thalamus, there was a trend for reduced [(3)H]nicotine binding in the majority of nuclei (0-20%) in Alzheimer's disease; however, there was a significant decline in [(125)I]alpha-bungarotoxin binding in the reticular nucleus. In the striatum [(3)H]nicotine binding was reduced in Alzheimer's disease, and although neuroleptic medication accentuated this change, it occurred in those free of neuroleptics. Changes in nicotinic acetylcholine receptors in Alzheimer's disease are distinct from those in normal aging and are likely to contribute to clinical features and possibly neuropathology.
Collapse
Affiliation(s)
- J Court
- Joint MRC Newcastle University Centre Development in Clinical Brain Aging, Institute for the Health of the Elderly, Newcastle General Hospital, Newcastle upon Tyne, United Kingdom
| | | | | | | | | | | |
Collapse
|
31
|
Court JA, Martin-Ruiz C, Graham A, Perry E. Nicotinic receptors in human brain: topography and pathology. J Chem Neuroanat 2000; 20:281-98. [PMID: 11207426 DOI: 10.1016/s0891-0618(00)00110-1] [Citation(s) in RCA: 137] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Brain nicotinic acetylcholine receptors (nAChR) are a class of ligand-gated channels composed of alpha and beta subunits with specific structural, functional and pharmacological properties. They participate in the physiological and behavioural effects of acetylcholine and mediate responses to nicotine. They are associated with numerous transmitter systems and their expression is altered during development and ageing as well as in diseases such as autism, schizophrenia, Alzheimer's disease, Parkinson's disease and Lewy body dementia. Nicotinic receptors containing a number of different subunits are highly expressed during early human development. Disorders believed to be associated with abnormal brain maturation involve deficits in both alpha4beta2, in the case of autism, and alpha7 possibly in addition to alpha4beta2 nAChRs in the case of schizophrenia. In ageing and age-related neurodegenerative disorders nAChR deficits are predominantly associated with alpha4-containing receptors, although some studies also indicate the involvement of alpha3 and alpha7 subunits. Whilst ageing appears to be associated with reductions in subunit mRNA as well as protein expression, in Alzheimer's disease only protein loss is apparent. Nicotinic therapy may be of benefit in a number of neurological conditions, however studies evaluating further both the distribution of specific subunit involvement and the correlation of nAChR deficits with clinical symptoms are required to inform therapeutic strategy.
Collapse
Affiliation(s)
- J A Court
- Joint MRC-Newcastle University, Development in Clinical Brain Ageing, MRC Building, Newcastle General Hospital, Westgate Road, Newcastle upon Tyne NE4 6BE, UK.
| | | | | | | |
Collapse
|
32
|
Wevers A, Burghaus L, Moser N, Witter B, Steinlein OK, Schütz U, Achnitz B, Krempel U, Nowacki S, Pilz K, Stoodt J, Lindstrom J, De Vos RA, Jansen Steur EN, Schröder H. Expression of nicotinic acetylcholine receptors in Alzheimer's disease: postmortem investigations and experimental approaches. Behav Brain Res 2000; 113:207-15. [PMID: 10942047 DOI: 10.1016/s0166-4328(00)00215-1] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Nicotinic ligand binding studies have shown rather early that the cholinoceptive system is affected in Alzheimer's disease (AD). Today, molecular histochemistry enables one to study the nicotinic acetylcholine receptor (nAChR) subunit expression on the cellular level in human autopsy brains, in animal models and in in vitro approaches, thus deciphering the distribution of nAChRs and their role as potential therapeutic targets. The studies on the nAChR expression in the frontal and temporal cortex of AD patients and age-matched controls could demonstrate that both, the numbers of alpha4- and alpha7-immunoreactive neurons and the quantitative amount, in particular of the alpha4 protein, were markedly decreased in AD. Because the number of the corresponding mRNA expressing neurons was unchanged these findings point to a translational/posttranslational rather than a transcriptional event as an underlying cause. This assumption is supported by direct mutation screening of the CHRNA4 gene which showed no functionally important mutations. To get more insight into the underlying mechanisms, two model systems organotypic culture and primary hippocampal culture - have been established, both allowing to mimic nAChR expression in vitro. In ongoing studies the possible impact of beta-amyloid (Abeta) on nAChR expression is tested. Preliminary results obtained from primary cultures point to an impaired nAChR expression following Abeta exposure.
Collapse
Affiliation(s)
- A Wevers
- Department of Anatomy, Neuroanatomy, University of Cologne, Germany.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Hellström-Lindahl E, Court JA. Nicotinic acetylcholine receptors during prenatal development and brain pathology in human aging. Behav Brain Res 2000; 113:159-68. [PMID: 10942042 DOI: 10.1016/s0166-4328(00)00210-2] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Nicotinic acetylcholine receptor (nAChRs) proteins and gene transcripts are already present in human prenatal brain and spinal cord at 4-6 weeks gestation, and a clear age-related increase in number of nAChRs was apparent during first trimester. In pons, there was also a parallel increase in the alpha7 mRNA level with age. The highest specific binding of [3H]epibatidine and [3H]cytisine was detected in spinal cord, pons and medulla oblongata, and binding of [125I]alpha-bungarotoxin was highest in spinal cord, medulla oblongata and mesencephalon. From the late fetal stage brain nAChRs have been shown to fall with increasing age. During aging (between 40 and 100 years) high affinity nicotine binding in the frontal cortex decreases in parallel with glutamate NMDA receptor binding ([3H]MK801). In the hippocampal formation and entorhinal cortex nicotine binding also declines with age, in common with [125I]alpha-bungarotoxin in the entorhinal cortex, but NMDA receptor binding remains unchanged. These reductions in nicotine binding with age may predispose the neo- and archicortex to the loss of nAChRs observed in age-associated neurodegenerative conditions. By contrast no loss in nAChR binding with aging is observed in the thalamus and only after the 70th decade in the striatum, although in Alzheimer's disease, Parkinson's disease and Lewy body dementia deficits in nAChRs are observed in these areas and may be associated with specific disease-related processes.
Collapse
Affiliation(s)
- E Hellström-Lindahl
- Department of Clinical Neuroscience, Occupational Therapy and Elderly Care Research, Karolinska Institutet, Huddinge University Hospital, Sweden.
| | | |
Collapse
|
34
|
Weiland S, Bertrand D, Leonard S. Neuronal nicotinic acetylcholine receptors: from the gene to the disease. Behav Brain Res 2000; 113:43-56. [PMID: 10942031 DOI: 10.1016/s0166-4328(00)00199-6] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The neuronal nicotinic acetylcholine receptors are excitatory ligand-gated channels. Widely expressed throughout the peripheral and central nervous system, their properties depend upon their subunit composition. Furthermore, genetic studies have revealed a high degree of variation at the genomic level and alternative splicing of the mRNAs coding for these integral membrane proteins. In particular, genes coding for alpha4 and alpha7 subunits harbour a high degree of polymorphisms. Although well characterised at their molecular and functional level, the role of these receptors in the central nervous system remains obscure. Despite accumulating evidence for the participation of nicotinic receptors in disorders of the central nervous system including nicotinic addiction, Parkinson's disease, Alzheimer's disease and Tourette's syndrome, the exact role of these receptors is still speculative. Because most of these phenotypes are complex and genetically heterogeneous, the investigation is difficult. However, in the past few years, significant progress has been made in understanding the contribution of nicotinic acetylcholine receptors to the origin of epilepsies and schizophrenia. By concentrating on the latest results gained for these diseases, we discuss in this review the possible relationships between neuronal nicotinic receptors and neurological and psychiatric disorders.
Collapse
Affiliation(s)
- S Weiland
- Department of Physiology, Faculty of Medicine, CMU, Geneva, Switzerland
| | | | | |
Collapse
|
35
|
Abstract
Neuronal nicotinic acetylcholine receptors (nAChRs) are a family of ligand gated ion channels which are widely distributed in the human brain. Multiple subtypes of these receptors exist, each with individual pharmacological and functional profiles. They mediate the effects of nicotine, a widely used drug of abuse, are involved in a number of physiological and behavioural processes and are additionally implicated in a number of pathological conditions such as Alzheimer's disease, Parkinson's disease and schizophrenia. The nAChRs have a pentameric structure composed of five membrane spanning subunits, of which nine different types have thus far been identified and cloned. The multiple subunits identified provide the basis for the heterogeneity of structure and function observed in the nAChR subtypes and are responsible for the individual characteristics of each. A substantial amount of information on human nAChR structure and function has come from studies on neuroblastoma cell lines which naturally express nAChRs and from recombinant nAChRs expressed in Xenopus oocytes. In vitro brain nAChR distribution can be mapped with a number of appropriate agonist and antagonist radioligands and subunit distribution may be mapped by in situ hybridization using subunit specific mRNA probes. Receptor distribution in the living human brain can be studied with noninvasive imaging techniques such as PET and SPECT, with a significant reduction in nAChRs in the brains of Alzheimer's patients having been identified with [11C] nicotine in PET studies. Despite the significant body of knowledge now accumulated about nAChRs, much remains to be elucidated. This review will attempt to describe the current knowledge on the nAChR subtypes in the human brain, their functional roles and neuropathological involvement.
Collapse
Affiliation(s)
- D Paterson
- Department of Clinical Neuroscience, Occupational Therapy and Elderly Care Research, Karolinska Institute, Huddinge Univerity Hospital, Sweden
| | | |
Collapse
|
36
|
Perry E, Martin-Ruiz C, Lee M, Griffiths M, Johnson M, Piggott M, Haroutunian V, Buxbaum JD, Nãsland J, Davis K, Gotti C, Clementi F, Tzartos S, Cohen O, Soreq H, Jaros E, Perry R, Ballard C, McKeith I, Court J. Nicotinic receptor subtypes in human brain ageing, Alzheimer and Lewy body diseases. Eur J Pharmacol 2000; 393:215-22. [PMID: 10771016 DOI: 10.1016/s0014-2999(00)00064-9] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Human brain ageing is associated with reductions in a variety of nicotinic receptors subtypes, whereas changes in age-related disorders including Alzheimer's disease or Parkinson's disease are more selective. In Alzheimer's disease, in the cortex there is a selective loss of the alpha4 (but not alpha3 or 7) subunit immunoreactivity and of nicotine or epibatidine binding but not alpha-bungarotoxin binding. Epibatidine binding is inversely correlated with clinical dementia ratings and with the level of Abeta1-42, but not related to plaque or tangle densities. In contrast, alpha-bungarotoxin binding is positively correlated with plaque densities in the entorhinal cortex. In human temporal cortex loss of acetylcholinesterase catalytic activity is positively correlated with decreased epibatidine binding and in a transgenic mouse model over expressing acetylcholinesterase, epibatidine binding is elevated. In Parkinson's disease, loss of striatal nicotine binding appears to occur early but is not associated with a loss of alpha4 subunit immunoreactivity. Tobacco use in normal elderly individuals is associated with increased alpha4 immunoreactivity in the cortex and lower densities of amyloid-beta plaques, and with greater numbers of dopaminergic neurons in the substantia nigra pars compacta. These findings indicate an early involvement of the alpha4 subunit in beta-amyloidosis but not in nigro-striatal dopaminergic degeneration.
Collapse
Affiliation(s)
- E Perry
- Department of Neuropathology, MRC Neurochemical Pathology Unit, Newcastle General Hospital, Westgate Road, Newcastle, UK.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Charpantier E, Besnard F, Graham D, Sgard F. Diminution of nicotinic receptor alpha 3 subunit mRNA expression in aged rat brain. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1999; 118:153-8. [PMID: 10611514 DOI: 10.1016/s0165-3806(99)00157-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Losses in nicotinic acetylcholine receptors (nAChRs) have been linked to a decline in cognitive function in patients with neurodegenerative diseases, but the impact of normal aging on the different neuronal nicotinic receptor subunits has yet to be fully characterized. The expression pattern of nine nAChR subunits mRNA (alpha2-7 and beta2-4) was investigated in this study in young and aged rat brains, 5 weeks and 30 months old, respectively. Microtissue samples were dissected from brain slices and nAChR subunit mRNA expression was analyzed by reverse transcription polymerase chain reaction (RT-PCR) from eight different brain areas. In several regions, a loss of PCR signal was found for the alpha3, and to a lesser extent, for alpha2 subunit mRNA in aged rat brain. A relative quantification of alpha3 and alpha4 mRNA expression was then carried out in four of these brain regions. A significant diminution of alpha3 expression level was observed in all regions tested while, in comparison, much less modification in alpha4 mRNA was detected. This decrease in alpha3 subunit mRNA may represent a selective degradation of neurons expressing the alpha3 subunit or a diminution of alpha3-containing nAChR subtypes in those neurons during aging.
Collapse
Affiliation(s)
- E Charpantier
- Department of Genomic Biology, Synthélabo Recherche, 10 Rue des Carrières, Rueil-Malmaison, France
| | | | | | | |
Collapse
|
38
|
Sihver W, Gillberg PG, Svensson AL, Nordberg A. Autoradiographic comparison of [3H](-)nicotine, [3H]cytisine and [3H]epibatidine binding in relation to vesicular acetylcholine transport sites in the temporal cortex in Alzheimer's disease. Neuroscience 1999; 94:685-96. [PMID: 10579560 DOI: 10.1016/s0306-4522(99)00295-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The laminar binding distribution of three nicotinic receptor agonists, [3H](-)nicotine, [3H]cytisine, and [3H]epibatidine, and their relation to the [3H]vesamicol binding, which is known to represent the vesicular acetylcholine transport sites, was performed employing in vitro autoradiography on the medial temporal cortex (Brodmann area 21). Autopsied brain tissue from nine Alzheimer patients and seven age-matched controls were used. The binding pattern of the three nicotinic ligands in the normal cortex was in general similar, showing binding maxima in the cortical layers I, III and V. The binding of [3H](-)nicotine, [3H]cytisine, and [3H]epibatidine was lower in the older controls and more uniform throughout the layers as compared with younger controls. There was a significant age-related decrease in the binding of the three nicotinic ligands within the controls (age range: 58 to 89 years; P[3H](-)nicotine = 0.002, P[3H]epibatidine = 0.010, P[3H]cytisine = 0.037). In the older controls, the [3H]epibatidine binding was much decreased as compared with that of [3H](-)nicotine and [3H]cytisine. This may indicate a higher selectivity of [3H]epibatidine for a nicotinic receptor subtype that is particularly affected by aging. The laminar binding pattern of [3H]vesamicol showed one maximum in the outer cortical layers II/III. The [3H]vesamicol binding did not change with aging. The binding of all ligands was significantly decreased in all layers of the temporal cortex in Alzheimer's disease, but the [3H]vesamicol binding decreased only half as much as the nicotinic receptors. Also, choline acetyltransferase activity was percentually more reduced than [3H]vesamicol binding in Alzheimer's disease. The cortical laminar binding pattern of all 3H-ligands was largely absent in the Alzheimer's disease cases. The less severe loss of vesicular acetylcholine transport sites as compared with the loss of the nicotinic receptors and choline acetyltransferase activity may suggest that vesamicol binding sites might be more preserved in presynaptic terminals still existing and thereby expressing compensatory capacity to maintain cholinergic activity.
Collapse
Affiliation(s)
- W Sihver
- PET Center Uppsala, Uppsala University, Sweden.
| | | | | | | |
Collapse
|
39
|
Utsugisawa K, Nagane Y, Tohgi H, Yoshimura M, Ohba H, Genda Y. Changes with aging and ischemia in nicotinic acetylcholine receptor subunit alpha7 mRNA expression in postmortem human frontal cortex and putamen. Neurosci Lett 1999; 270:145-8. [PMID: 10462115 DOI: 10.1016/s0304-3940(99)00473-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Age-related changes in nicotinic acetylcholine receptor (nAChR) subunit alpha7 messenger RNA (mRNA) expression in postmortem human frontal cortex and putamen of controls and status lacunaris patients were investigated using nonradioactive reverse transcription(RT)-PCR. In the frontal cortex of control brains, alpha7 subunit mRNA significantly decreased with age (P < 0.05). In the putamen, alpha7 subunit mRNA expression was significantly lower than that in the frontal cortex (P < 0.0001), and showed no significant correlation with age. However, in cases with status lacunaris in the putamen, alpha7 subunit mRNA expression was significantly higher compared with controls (P < 0.001). The reduction in alpha7 nAChR in the frontal cortex with age may decrease functional cholinergic synapses and cortical activity, and play a role in the cognitive impairments associated with normal aging. The functional significance of the upregulation of alpha7 nAChR mRNA in ischemic conditions remains to be determined.
Collapse
Affiliation(s)
- K Utsugisawa
- Department of Neurology, Iwate Medical University, Morioka, Japan
| | | | | | | | | | | |
Collapse
|
40
|
Utsugisawa K, Tohgi H, Yoshimura M, Nagane Y, Ukitsu M. Quantitation of nicotinic acetylcholine receptor subunits alpha 4 and beta 2 messenger RNA in postmortem human brain using a non-radioactive RT-PCR and CCD imaging system. BRAIN RESEARCH. BRAIN RESEARCH PROTOCOLS 1999; 4:92-6. [PMID: 10234456 DOI: 10.1016/s1385-299x(99)00011-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We present a simple and rapid procedure for quantifying mRNA in the brain after RT-PCR, in which the intensity of the ethidium bromide luminescence of PCR products is measured directly from electrophoretic gels by a highly sensitive CCD camera combined with an image analyzing computer system (Gel Doc 1000 system). The CCD camera allows the mRNA in the ethidium bromide-stained PCR-amplified bands to be quantified in a broad exponential range of PCR cycles. The proposed protocol enables standard curves to be constructed to examine the relationship between the number of reaction cycles and amplified log intensity and between the amount of sample RNA for RT-PCR and amplified intensity. The method was applied to nicotinic acetylcholine receptor (nAChR) subunits alpha 4 and beta 2 mRNA in postmortem human putamen in the present study, but is also applicable to mRNAs of other receptors and neurotransmitter precursor peptides.
Collapse
Affiliation(s)
- K Utsugisawa
- Department of Neurology, Iwate Medical University, Morioka, Japan
| | | | | | | | | |
Collapse
|
41
|
Terzano S, Court JA, Fornasari D, Griffiths M, Spurden DP, Lloyd S, Perry RH, Perry EK, Clementi F. Expression of the alpha3 nicotinic receptor subunit mRNA in aging and Alzheimer's disease. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1998; 63:72-8. [PMID: 9838051 DOI: 10.1016/s0169-328x(98)00260-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Changes in the number of high-affinity nicotine binding sites have been widely reported in specific regions of the human brain during aging and in degenerative neurological diseases associated with aging, such as Alzheimer's disease. Nicotinic receptors are highly diverse and a description of the molecular subtypes affected in such conditions has not been achieved to date. To investigate the status of the alpha3 subunit-containing subtypes in such conditions, we assessed by in situ hybridisation the alpha3 mRNA density in the hippocampus, entorhinal cortex and thalamus of Alzheimer's patients and age-matched controls. No significant difference in the expression of the alpha3 mRNA, either qualitative or quantitative, was found between Alzheimer's individuals and controls in any of the analysed areas. This result suggests that the nicotine binding changes occurring in these areas in Alzheimer's patients are not correlated to a variation of the alpha3 mRNA in the same regions. Nevertheless, a negative correlation between the alpha3 mRNA density and the age was observed in the entorhinal cortex of both the Alzheimer's and the normal subjects, suggesting a potentially extensive decay of the alpha3-expressing neurons or loss of alpha3-containing receptors in intact neurons of the entorhinal cortex in the late elderly.
Collapse
Affiliation(s)
- S Terzano
- CNR Cellular and Molecular Pharmacology Center, Department of Medical Pharmacology, University of Milan, Via Vanvitelli 32, 20129, Milan, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Tohgi H, Utsugisawa K, Yoshimura M, Nagane Y, Mihara M. Age-related changes in nicotinic acetylcholine receptor subunits alpha4 and beta2 messenger RNA expression in postmortem human frontal cortex and hippocampus. Neurosci Lett 1998; 245:139-42. [PMID: 9605475 DOI: 10.1016/s0304-3940(98)00205-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Age-related changes in nicotinic acetylcholine receptor (nAChR) subunit alpha4 and beta2 messenger RNA (mRNA) expression in the postmortem human frontal cortex and hippocampus was investigated using the reverse transcription-polymerase chain reaction (RT-PCR). In the frontal cortex, both alpha4 and beta2 subunit mRNA expression decreased with age. In the hippocampus, alpha4 subunit mRNA expression was unaltered, while beta2 subunit mRNA expression significantly decreased with age. These findings suggest that nAChR transcription decreases during aging with differing vulnerability between subunits and brain regions, which could in part contribute to the reduction in cognitive functions seen in the elderly.
Collapse
Affiliation(s)
- H Tohgi
- Department of Neurology, Iwate Medical University, Morioka, Japan
| | | | | | | | | |
Collapse
|