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Orciani C, Hall H, Pentz R, Foret MK, Do Carmo S, Cuello AC. Long-term nucleus basalis cholinergic depletion induces attentional deficits and impacts cortical neurons and BDNF levels without affecting the NGF synthesis. J Neurochem 2022; 163:149-167. [PMID: 35921478 DOI: 10.1111/jnc.15683] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/26/2022] [Accepted: 07/29/2022] [Indexed: 11/26/2022]
Abstract
Basal forebrain cholinergic neurons (BFCNs) represent the main source of cholinergic innervation to the cortex and hippocampus and degenerate early in Alzheimer's disease (AD) progression. Phenotypic maintenance of BFCNs depends on levels of mature nerve growth factor (mNGF) and mature brain-derived neurotrophic factor (mBDNF), produced by target neurons and retrogradely transported to the cell body. Whether a reciprocal interaction where BFCN inputs impact neurotrophin availability and affect cortical neuronal markers is unknown. To address our hypothesis, we immunolesioned the nucleus basalis (nb), a basal forebrain cholinergic nuclei projecting mainly to the cortex, by bilateral stereotaxic injection of 192-IgG-Saporin (the cytotoxin Saporin binds p75ntr receptors expressed exclusively by BFCNs) in 2.5-month-old Wistar rats. At six months post-lesion, Saporin-injected rats (SAP) showed an impairment in a modified version of the 5-Choice Serial Reaction Time Task (5-choice task). Post-mortem analyses of the brain revealed a reduction of Choline Acetyltransferase-immunoreactive neurons compared to wild-type controls. A diminished number of cortical vesicular acetylcholine transporter-immunoreactive boutons was accompanied by a reduction in BDNF mRNA, mBDNF protein levels, markers of glutamatergic (vGluT1) and GABAergic (GAD65) neurons in the SAP-group compared to the controls. NGF mRNA, NGF precursor and mNGF protein levels were not affected. Additionally, cholinergic markers correlated with the attentional deficit and BDNF levels. Our findings demonstrate that while cholinergic nb loss impairs cognition and reduces cortical neuron markers, it produces differential effects on neurotrophin availability, affecting BDNF but not NGF levels.
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Affiliation(s)
- Chiara Orciani
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Helene Hall
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - Rowan Pentz
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Morgan K Foret
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - Sonia Do Carmo
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - A Claudio Cuello
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada.,Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada.,Department of Pharmacology, Oxford University, US (Visiting Professor)
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2
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Moschonas EH, Leary JB, Memarzadeh K, Bou-Abboud CE, Folweiler KA, Monaco CM, Cheng JP, Kline AE, Bondi CO. Disruption of basal forebrain cholinergic neurons after traumatic brain injury does not compromise environmental enrichment-mediated cognitive benefits. Brain Res 2020; 1751:147175. [PMID: 33121921 DOI: 10.1016/j.brainres.2020.147175] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 10/08/2020] [Accepted: 10/21/2020] [Indexed: 12/22/2022]
Abstract
Environmental enrichment (EE) attenuates traumatic brain injury (TBI)-induced loss of medial septal (MS) choline acetyltransferase (ChAT)-cells and enhances spatial learning and memory vs. standard (STD) housing. Whether basal forebrain cholinergic neurons (BFCNs) are important mediators of EE-induced benefits after TBI requires further investigation. Anesthetized female rats were randomly assigned to intraseptal infusions of the immunotoxin 192-IgG-saporin (SAP; 0.22 μg in 1.0 μL) or vehicle (VEH; 1.0 μL IgG) followed immediately by a cortical impact (2.8 mm deformation depth at 4 m/s) or sham injury and divided into EE and STD housing. Spatial learning and memory retention were assessed on post-operative days 14-19. MS ChAT+ cells were quantified at 3 weeks. SAP significantly reduced ChAT+ cells in both the EE and STD groups. Cognitive performance was improved in the EE groups, regardless of VEH or SAP infusion, vs. the STD-housed groups (p's < 0.05). No cognitive differences were revealed between the TBI + EE + SAP and TBI + EE + VEH groups (p > 0.05) or between the TBI + STD + SAP and TBI + STD + VEH groups (p > 0.05). These data show that despite significant MS ChAT+ cell loss, the EE-mediated benefit in cognitive recovery is not compromised.
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Affiliation(s)
- Eleni H Moschonas
- Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States
| | - Jacob B Leary
- Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States
| | - Kimiya Memarzadeh
- Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States
| | - Carine E Bou-Abboud
- Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States
| | - Kaitlin A Folweiler
- Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States
| | - Christina M Monaco
- Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States
| | - Jeffrey P Cheng
- Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States
| | - Anthony E Kline
- Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States; Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States; Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, United States; Psychology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Corina O Bondi
- Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States; Neurobiology, University of Pittsburgh, Pittsburgh, PA, United States.
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3
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Meléndez DM, Nordquist RE, Vanderschuren LJMJ, van der Staay FJ. Spatial memory deficits after vincristine-induced lesions to the dorsal hippocampus. PLoS One 2020; 15:e0231941. [PMID: 32315349 PMCID: PMC7173870 DOI: 10.1371/journal.pone.0231941] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 04/04/2020] [Indexed: 11/23/2022] Open
Abstract
Vincristine is a commonly used cytostatic drug for the treatment of leukemia, neuroblastoma and lung cancer, which is known to have neurotoxic properties. The aim of this study was to assess the effects of vincristine, injected directly into the dorsal hippocampus, in spatial memory using the spatial cone field discrimination task. Long Evans rats were trained in the cone field, and after reaching training criterion received bilateral vincristine infusions into the dorsal hippocampus. Vincristine-treated animals presented unilateral or bilateral hippocampal lesions. Animals with bilateral lesions showed lower spatial working and reference memory performance than control animals, but task motivation was unaffected by the lesions. Working and reference memory of animals with unilateral lesions did not differ from animals with bilateral lesions and control animals. In sum, intrahippocampal injection of vincristine caused profound tissue damage in the dorsal hippocampus, associated with substantial cognitive deficits.
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Affiliation(s)
- Daniela M. Meléndez
- Division of Farm Animal Health, Department of Population Health Sciences, Behaviour and Welfare Group, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Rebecca E. Nordquist
- Division of Farm Animal Health, Department of Population Health Sciences, Behaviour and Welfare Group, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
- Department of Population Health Sciences, Animals in Science and Society, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
- * E-mail:
| | - Louk J. M. J. Vanderschuren
- Department of Population Health Sciences, Animals in Science and Society, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Franz-Josef van der Staay
- Division of Farm Animal Health, Department of Population Health Sciences, Behaviour and Welfare Group, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
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4
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Tao X, Yan M, Wang L, Zhou Y, Wang Z, Xia T, Liu X, Pan R, Chang Q. Effects of estrogen deprivation on memory and expression of related proteins in ovariectomized mice. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:356. [PMID: 32355800 PMCID: PMC7186664 DOI: 10.21037/atm.2020.02.57] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Background The ovariectomized (OVX) rodent model is most widely used for studying the influence of estrogen deprivation on memory. However, the results of these studies are inconsistent, in that the memory of OVX rodents shows either impairment or no change. These inconsistent outcomes increase the difficulty of researching neurochemical mechanisms and evaluating drug efficacy. One possible explanation for these discrepancies might be that the time point for memory examination after OVX varies considerably among studies. The aim of our study was to investigate the effects of estrogen deprivation on memory and the expression of memory-related proteins at different times after OVX. Methods Novel object recognition (NOR), step-through passive avoidance (STPA) and the Morris water maze (MWM) were performed to evaluate the memory performance of mice at different times after OVX. The expressions of BDNF, TrkB, ULK1 and LC3II/LC3I in the hippocampus were also assessed to explore the relevant mechanisms. Results After OVX, a significant memory impairment was found in the STPA test at 4 weeks. In the NOR and MWM tests, however, memory deficits were not observed until 8 weeks post-OVX. Interestingly, at 8 weeks, a memory rebound was found in the STPA test. In the hippocampus, the levels of BDNF and TrkB in OVX mice were markedly decreased at 4 and 8 weeks. Subsequently, a significant decrease in the ULK1 and LC3II/LC3I level in OVX mice was observed at 8 weeks. Conclusions Memory impairment in mice was observed as early as 4 weeks after OVX, although there was a possibility of memory rebound with the prolongation of estrogen deprivation. Eight weeks of estrogen deprivation would be more likely to induce hippocampus-dependent memory impairment. This progressive impairment of memory might be due to the downregulation of the BDNF/TrkB signaling pathway at the early post-OVX stage, while the decrease of autophagy level in the later stage might also contribute to these progressive alterations. The underlying relationship between the BDNF/TrkB signaling pathway and autophagy in this progressive impairment of memory requires further study.
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Affiliation(s)
- Xue Tao
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China
| | - Mingzhu Yan
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China
| | - Lisha Wang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China
| | - Yunfeng Zhou
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China
| | - Zhi Wang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China
| | - Tianji Xia
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China
| | - Xinmin Liu
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China.,National Key Laboratory of Human Factors Engineering and the State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing 100094, China
| | - Ruile Pan
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China
| | - Qi Chang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China
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5
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Zielinski MC, Tang W, Jadhav SP. The role of replay and theta sequences in mediating hippocampal-prefrontal interactions for memory and cognition. Hippocampus 2018; 30:60-72. [PMID: 29251801 DOI: 10.1002/hipo.22821] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 12/03/2017] [Accepted: 12/10/2017] [Indexed: 11/05/2022]
Abstract
Sequential activity is seen in the hippocampus during multiple network patterns, prominently as replay activity during both awake and sleep sharp-wave ripples (SWRs), and as theta sequences during active exploration. Although various mnemonic and cognitive functions have been ascribed to these hippocampal sequences, evidence for these proposed functions remains primarily phenomenological. Here, we briefly review current knowledge about replay events and theta sequences in spatial memory tasks. We reason that in order to gain a mechanistic and causal understanding of how these patterns influence memory and cognitive processing, it is important to consider how these sequences influence activity in other regions, and in particular, the prefrontal cortex, which is crucial for memory-guided behavior. For spatial memory tasks, we posit that hippocampal-prefrontal interactions mediated by replay and theta sequences play complementary and overlapping roles at different stages in learning, supporting memory encoding and retrieval, deliberative decision making, planning, and guiding future actions. This framework offers testable predictions for future physiology and closed-loop feedback inactivation experiments for specifically targeting hippocampal sequences as well as coordinated prefrontal activity in different network states, with the potential to reveal their causal roles in memory-guided behavior.
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Affiliation(s)
- Mark C Zielinski
- Graduate Program in Neuroscience, Brandeis University, Waltham, Massachusetts, 02453
| | - Wenbo Tang
- Graduate Program in Neuroscience, Brandeis University, Waltham, Massachusetts, 02453
| | - Shantanu P Jadhav
- Neuroscience Program, Department of Psychology and Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts, 02453
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6
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Schambra UB, Lewis CN, Harrison TA. Deficits in spatial learning and memory in adult mice following acute, low or moderate levels of prenatal ethanol exposure during gastrulation or neurulation. Neurotoxicol Teratol 2017; 62:42-54. [DOI: 10.1016/j.ntt.2017.05.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 03/26/2017] [Accepted: 05/01/2017] [Indexed: 11/17/2022]
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7
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Wang Y, Roth Z, Pastalkova E. Synchronized excitability in a network enables generation of internal neuronal sequences. eLife 2016; 5. [PMID: 27677848 PMCID: PMC5089858 DOI: 10.7554/elife.20697] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 09/13/2016] [Indexed: 02/05/2023] Open
Abstract
Hippocampal place field sequences are supported by sensory cues and network internal mechanisms. In contrast, sharp-wave (SPW) sequences, theta sequences, and episode field sequences are internally generated. The relationship of these sequences to memory is unclear. SPW sequences have been shown to support learning and have been assumed to also support episodic memory. Conversely, we demonstrate these SPW sequences were present in trained rats even after episodic memory was impaired and after other internal sequences - episode field and theta sequences - were eliminated. SPW sequences did not support memory despite continuing to 'replay' all task-related sequences - place- field and episode field sequences. Sequence replay occurred selectively during synchronous increases of population excitability -- SPWs. Similarly, theta sequences depended on the presence of repeated synchronized waves of excitability - theta oscillations. Thus, we suggest that either intermittent or rhythmic synchronized changes of excitability trigger sequential firing of neurons, which in turn supports learning and/or memory.
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Affiliation(s)
- Yingxue Wang
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Zachary Roth
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, United States.,Department of Mathematics, University of Nebraska-Lincoln, Lincoln, United States
| | - Eva Pastalkova
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, United States
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8
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Okada K, Nishizawa K, Kobayashi T, Sakata S, Kobayashi K. Distinct roles of basal forebrain cholinergic neurons in spatial and object recognition memory. Sci Rep 2015; 5:13158. [PMID: 26246157 PMCID: PMC4526880 DOI: 10.1038/srep13158] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 07/13/2015] [Indexed: 11/18/2022] Open
Abstract
Recognition memory requires processing of various types of information such as objects and locations. Impairment in recognition memory is a prominent feature of amnesia and a symptom of Alzheimer’s disease (AD). Basal forebrain cholinergic neurons contain two major groups, one localized in the medial septum (MS)/vertical diagonal band of Broca (vDB), and the other in the nucleus basalis magnocellularis (NBM). The roles of these cell groups in recognition memory have been debated, and it remains unclear how they contribute to it. We use a genetic cell targeting technique to selectively eliminate cholinergic cell groups and then test spatial and object recognition memory through different behavioural tasks. Eliminating MS/vDB neurons impairs spatial but not object recognition memory in the reference and working memory tasks, whereas NBM elimination undermines only object recognition memory in the working memory task. These impairments are restored by treatment with acetylcholinesterase inhibitors, anti-dementia drugs for AD. Our results highlight that MS/vDB and NBM cholinergic neurons are not only implicated in recognition memory but also have essential roles in different types of recognition memory.
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Affiliation(s)
- Kana Okada
- Department of Behavioural Sciences, Graduate School of Integrated Arts &Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan
| | - Kayo Nishizawa
- Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima 960-1295, Japan
| | - Tomoko Kobayashi
- Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima 960-1295, Japan
| | - Shogo Sakata
- Department of Behavioural Sciences, Graduate School of Integrated Arts &Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan
| | - Kazuto Kobayashi
- 1] Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima 960-1295, Japan [2] Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Kawaguchi 332-0012, Japan
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9
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Guitar NA, Roberts WA. The interaction between working and reference spatial memories in rats on a radial maze. Behav Processes 2014; 112:100-7. [PMID: 25452076 DOI: 10.1016/j.beproc.2014.10.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 09/25/2014] [Accepted: 10/19/2014] [Indexed: 11/28/2022]
Abstract
The interaction of reference and working memory was studied in rats on an eight-arm radial maze. Each trial involved a two-phase procedure in which a rat was forced to enter four arms on the maze in a study phase and then was allowed to choose among all eight arms in a test phase given 5-s later, with choice of only the previously unvisited arms rewarded. For each rat, two arms on the maze were designated as reference memory arms because they were never entered in the study phase and were always rewarded in the test phase. The other two arms never entered in the study phase and rewarded in the test phase were working memory arms and varied randomly from trial to trial. In Experiment 1, rats showed acquisition of equivalent preference for entering the reference and working memory arms in their first four choices of the test phase. Subsequent tests carried out in Experiment 2 compared performance at 5-s, 1-h, and 24-h retention intervals when reference memory and working memory were congruent and incongruent. Higher accuracy for choice of reference memory arms than working memory arms appeared at the 1-h and 24-h retention intervals on congruent tests but not on incongruent tests. A process dissociation procedure analysis indicated that working memory but not reference memory declined over the 24-h retention interval. The interaction of working and reference memory was shown by superior choice of reference memory arms on congruent tests than on incongruent tests at 1-h and 24-h retention intervals but not at the 5-s retention interval. These findings suggest that working and reference memory are independent systems that can facilitate and compete with one another. This article is part of a Special Issue entitled: Tribute to Tom Zentall.
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Affiliation(s)
- Nicole A Guitar
- Department of Psychology, Western University, London, Ontario N6A 5C2, Canada
| | - William A Roberts
- Department of Psychology, Western University, London, Ontario N6A 5C2, Canada.
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10
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Burke SN, Hartzell AL, Lister JP, Hoang LT, Barnes CA. Layer V perirhinal cortical ensemble activity during object exploration: a comparison between young and aged rats. Hippocampus 2012; 22:2080-93. [PMID: 22987683 PMCID: PMC3523702 DOI: 10.1002/hipo.22066] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Object recognition memory requires the perirhinal cortex (PRC) and this cognitive function declines during normal aging. Recent electrophysiological recordings from young rats have shown that neurons in Layer V of the PRC are activated by three-dimensional objects. Thus, it is possible that age-related object recognition deficits result from alterations in PRC neuron activity in older animals. To examine this, the present study used cellular compartment analysis of temporal activity by fluorescence in situ hybridization (catFISH) with confocal microscopy to monitor cellular distributions of activity-induced Arc RNA in layer V of the PRC. Activity was monitored during two distinct epochs of object exploration. In one group of rats (6 young/6 aged) animals were placed in a familiar testing arena and allowed to explore five different three-dimensional objects for two 5-min sessions separated by a 20-min rest (AA). The second group of animals (6 young/6 aged) also explored the same objects for two 5-min sessions, but the environment was changed between the first and the second epoch (AB). Behavioral data showed that both age groups spent less time exploring objects during the second epoch, even when the environment changed, indicating successful recognition. Although the proportion of active neurons between epochs did not change in the AA group, in the AB group more neurons were active during epoch 2 of object exploration. This recruitment of neurons into the active neural ensemble could serve to signal that familiar stimuli are being encountered in a new context. When numbers of Arc positive neurons were compared between age groups, the old rats had significantly lower proportions of Arc-positive PRC neurons in both the AA and AB behavioral conditions. These data support the hypothesis that age-associated functional alterations in the PRC contribute to declines in stimulus recognition over the lifespan.
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Affiliation(s)
- S N Burke
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85724, USA
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11
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Bizon JL, Foster TC, Alexander GE, Glisky EL. Characterizing cognitive aging of working memory and executive function in animal models. Front Aging Neurosci 2012; 4:19. [PMID: 22988438 PMCID: PMC3439637 DOI: 10.3389/fnagi.2012.00019] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 06/21/2012] [Indexed: 11/17/2022] Open
Abstract
Executive functions supported by prefrontal cortical (PFC) systems provide essential control and planning mechanisms to guide goal-directed behavior. As such, age-related alterations in executive functions can mediate profound and widespread deficits on a diverse array of neurocognitive processes. Many of the critical neuroanatomical and functional characteristics of prefrontal cortex are preserved in rodents, allowing for meaningful cross species comparisons relevant to the study of cognitive aging. In particular, as rodents lend themselves to genetic, cellular and biochemical approaches, rodent models of executive function stand to significantly contribute to our understanding of the critical neurobiological mechanisms that mediate decline of executive processes across the lifespan. Moreover, rodent analogs of executive functions that decline in human aging represent an essential component of a targeted, rational approach for developing and testing effective treatment and prevention therapies for age-related cognitive decline. This paper reviews behavioral approaches used to study executive function in rodents, with a focus on those assays that share a foundation in the psychological and neuroanatomical constructs important for human aging. A particular emphasis is placed on behavioral approaches used to assess working memory and cognitive flexibility, which are sensitive to decline with age across species and for which strong rodent models currently exist. In addition, other approaches in rodent behavior that have potential for providing analogs to functions that reliably decline to human aging (e.g., information processing speed) are discussed.
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Affiliation(s)
- Jennifer L Bizon
- Department of Neuroscience, Evelyn F. and William L. McKnight Brain Institute, University of Florida Gainesville, FL, USA
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12
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Pompili A, Arnone B, Gasbarri A. Estrogens and memory in physiological and neuropathological conditions. Psychoneuroendocrinology 2012; 37:1379-96. [PMID: 22309827 DOI: 10.1016/j.psyneuen.2012.01.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Revised: 01/13/2012] [Accepted: 01/13/2012] [Indexed: 12/22/2022]
Abstract
Ovarian hormones can influence brain regions crucial to higher cognitive functions, such as learning and memory, acting at structural, cellular and functional levels, and modulating neurotransmitter systems. Among the main effects of estrogens, the protective role that they may play against the deterioration of cognitive functions occurring with normal aging is of essential importance. In fact, during the last century, there has been a 30 years increase in female life expectancy, from 50 to 83 years; however, the mean age of spontaneous menopause remains stable, 50-51 years, with variability related to race and ethnicity. Therefore, women are now spending a greater fraction of their lives in a hypoestrogenic state. Although many cognitive functions seem to be unaffected by normal aging, age-related impairments are particularly evident in tasks involving working memory (WM), whose deficits are a recognized feature of Alzheimer's disease (AD). Many studies conducted over the past two decades showed that the female gonadal hormone estradiol can influence performance of learning and memory tasks, both in animal and humans. There is a great deal of evidence, mostly from animal models, that estrogens can facilitate or enhance performance on WM tasks; therefore, it is very important to clarify their role on this type of memory. To this aim, in this review we briefly describe the most relevant neurobiological bases of estrogens, that can explain their effects on cognitive functioning, and then we summarize the results of works conducted in our laboratory, both on animals and humans, utilizing the menstrual/estrous cycle as a useful noninvasive model. Finally, we review the possible role of estrogens in neuropathological conditions, such as AD and schizophrenia.
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Affiliation(s)
- Assunta Pompili
- Department of Biomedical Sciences and Technologies, University of L'Aquila, L'Aquila, Italy.
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13
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Easton A, Douchamps V, Eacott M, Lever C. A specific role for septohippocampal acetylcholine in memory? Neuropsychologia 2012; 50:3156-68. [PMID: 22884957 PMCID: PMC3605586 DOI: 10.1016/j.neuropsychologia.2012.07.022] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2011] [Revised: 05/28/2012] [Accepted: 07/12/2012] [Indexed: 11/30/2022]
Abstract
Acetylcholine has long been implicated in memory, including hippocampal-dependent memory, but the specific role for this neurotransmitter is difficult to identify in human neuropsychology. Here, we review the evidence for a mechanistic model of acetylcholine function within the hippocampus and consider its explanatory power for interpreting effects resulting from both pharmacological anticholinergic manipulations and lesions of the cholinergic input to the hippocampus in animals. We argue that these effects indicate that acetylcholine is necessary for some, but not all, hippocampal-dependent processes. We review recent evidence from lesion, pharmacological and electrophysiological studies to support the view that a primary function of septohippocampal acetylcholine is to reduce interference in the learning process by adaptively timing and separating encoding and retrieval processes. We reinterpret cholinergic-lesion based deficits according to this view and propose that acetylcholine reduces the interference elicited by the movement of salient locations between events.
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Affiliation(s)
- Alexander Easton
- Department of Psychology, University of Durham, Durham, DH1 3LE, UK.
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Tai SK, Leung LS. Vestibular stimulation enhances hippocampal long-term potentiation via activation of cholinergic septohippocampal cells. Behav Brain Res 2012; 232:174-82. [DOI: 10.1016/j.bbr.2012.04.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2011] [Revised: 03/29/2012] [Accepted: 04/08/2012] [Indexed: 01/07/2023]
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Kanju PM, Parameshwaran K, Sims-Robinson C, Uthayathas S, Josephson EM, Rajakumar N, Dhanasekaran M, Suppiramaniam V. Selective cholinergic depletion in medial septum leads to impaired long term potentiation and glutamatergic synaptic currents in the hippocampus. PLoS One 2012; 7:e31073. [PMID: 22355337 PMCID: PMC3280283 DOI: 10.1371/journal.pone.0031073] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Accepted: 01/02/2012] [Indexed: 12/02/2022] Open
Abstract
Cholinergic depletion in the medial septum (MS) is associated with impaired hippocampal-dependent learning and memory. Here we investigated whether long term potentiation (LTP) and synaptic currents, mediated by alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionate (AMPA) and N-methyl-D-aspartate (NMDA) receptors in the CA1 hippocampal region, are affected following cholinergic lesions of the MS. Stereotaxic intra-medioseptal infusions of a selective immunotoxin, 192-saporin, against cholinergic neurons or sterile saline were made in adult rats. Four days after infusions, hippocampal slices were made and LTP, whole cell, and single channel (AMPA or NMDA receptor) currents were recorded. Results demonstrated impairment in the induction and expression of LTP in lesioned rats. Lesioned rats also showed decreases in synaptic currents from CA1 pyramidal cells and synaptosomal single channels of AMPA and NMDA receptors. Our results suggest that MS cholinergic afferents modulate LTP and glutamatergic currents in the CA1 region of the hippocampus, providing a potential synaptic mechanism for the learning and memory deficits observed in the rodent model of selective MS cholinergic lesioning.
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Affiliation(s)
- Patrick M. Kanju
- Department of Pharmacal Sciences, Auburn University, Auburn, Alabama, United States of America
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Kodeeswaran Parameshwaran
- Department of Pharmacal Sciences, Auburn University, Auburn, Alabama, United States of America
- Department of Pathobiology, Auburn University, Auburn, Alabama, United States of America
| | - Catrina Sims-Robinson
- Department of Pharmacal Sciences, Auburn University, Auburn, Alabama, United States of America
- Department of Neurology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Subramaniam Uthayathas
- Department of Pharmacal Sciences, Auburn University, Auburn, Alabama, United States of America
- Department of Neurology, School of Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Eleanor M. Josephson
- Department of Anatomy, Physiology and Pharmacology, Auburn University, Auburn, Alabama, United States of America
| | - Nagalingam Rajakumar
- Department of Anatomy and Cell Biology, The University of Western Ontario, London, Ontario, Canada
| | | | - Vishnu Suppiramaniam
- Department of Pharmacal Sciences, Auburn University, Auburn, Alabama, United States of America
- * E-mail:
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Cai L, Gibbs RB, Johnson DA. Recognition of novel objects and their location in rats with selective cholinergic lesion of the medial septum. Neurosci Lett 2012; 506:261-5. [PMID: 22119001 PMCID: PMC3462014 DOI: 10.1016/j.neulet.2011.11.019] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 10/06/2011] [Accepted: 11/10/2011] [Indexed: 11/19/2022]
Abstract
The importance of cholinergic neurons projecting from the medial septum (MS) of the basal forebrain to the hippocampus in memory function has been controversial. The aim of this study was to determine whether loss of cholinergic neurons in the MS disrupts object and/or object location recognition in male Sprague-Dawley rats. Animals received intraseptal injections of either vehicle, or the selective cholinergic immunotoxin 192 IgG-saporin (SAP). 14 days later, rats were tested for novel object recognition (NOR). Twenty-four hours later, these same rats were tested for object location recognition (OLR) (recognition of a familiar object moved to a novel location). Intraseptal injections of SAP produced an 86% decrease in choline acetyltransferase (ChAT) activity in the hippocampus, and a 31% decrease in ChAT activity in the frontal cortex. SAP lesion had no significant effect on NOR, but produced a significant impairment in OLR in these same rats. The results support a role for septo-hippocampal cholinergic projections in memory for the location of objects, but not for novel object recognition.
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Affiliation(s)
- Li Cai
- Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA 15282
| | - Robert B. Gibbs
- Pharmaceutical Sciences, University of Pittsburgh School of Pharmacy, Pittsburgh, PA 15261
| | - David A. Johnson
- Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA 15282
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Burke SN, Wallace JL, Hartzell AL, Nematollahi S, Plange K, Barnes CA. Age-associated deficits in pattern separation functions of the perirhinal cortex: a cross-species consensus. Behav Neurosci 2011; 125:836-47. [PMID: 22122147 PMCID: PMC3255096 DOI: 10.1037/a0026238] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Normal aging causes a decline in object recognition. Importantly, lesions of the perirhinal cortex produce similar deficits and also lead to object discrimination impairments when the test objects share common features, suggesting that the perirhinal cortex participates in perceptual discrimination. The current experiments investigated the ability of young and aged animals to distinguish between objects that shared features with tasks with limited mnemonic demands. In the first experiment, young and old rats performed a variant of the spontaneous object recognition task in which there was a minimal delay between the sample and the test phase. When the test objects did not share any features ("Easy" perceptual discrimination) both young and aged rats correctly identified the novel object. When the test objects contained overlapping features, however, only the young rats showed an exploratory preference for the novel object. In Experiment 2, young and aged monkeys were tested on an object discrimination task. When the object pairs were dissimilar, both the young and aged monkeys learned to select the rewarded object quickly. In contrast, when LEGOs® were used to create object pairs with overlapping features, the aged monkeys took significantly longer than did the young animals to learn to discriminate between the rewarded and the unrewarded object. Together, these data indicate that behaviors requiring the perirhinal cortex are disrupted in advanced age, and suggest that at least some of these impairments may be explained by changes in high-level perceptual processing in advanced age.
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Affiliation(s)
- Sarah N Burke
- Evelyn F. McKnight Brain Institute, Division of Neural Systems Memory and Aging, University of Arizona, Tucson, AZ 85724, USA
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18
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Deiana S, Platt B, Riedel G. The cholinergic system and spatial learning. Behav Brain Res 2011; 221:389-411. [DOI: 10.1016/j.bbr.2010.11.036] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Accepted: 11/15/2010] [Indexed: 12/30/2022]
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19
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Marrone DF, Ramirez-Amaya V, Barnes CA. Neurons generated in senescence maintain capacity for functional integration. Hippocampus 2011; 22:1134-42. [PMID: 21695743 DOI: 10.1002/hipo.20959] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2011] [Indexed: 12/19/2022]
Abstract
Adult-born neurons in the dentate gyrus (DG) can survive for long periods, are capable of integrating into neuronal networks, and are important for hippocampus-dependent learning. Neurogenesis is dramatically reduced during senescence, and it remains unknown whether those few neurons that are produced remain capable of network integration. The expression of Arc, a protein coupled to neuronal activity, was used to measure activity among granule cells that were labeled with BrdU 4 months earlier in young (9 months) and aged (25 months) Fischer344 rats. The results indicate that while fewer cells are generated in the senescent DG, those that survive are (a) more likely to respond to spatial processing by expressing Arc relative to the remainder of the granule cell population and (b) equally responsive to spatial exploration as granule cells of the same age from young animals. These findings provide compelling evidence that newborn granule cells in the aged DG retain the capacity for participation in functional hippocampal networks.
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Affiliation(s)
- Diano F Marrone
- Department of Psychology, Wilfrid Laurier University, Waterloo, Ontario, Canada
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20
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Spatial memory alterations by activation of septal 5HT 1A receptors: no implication of cholinergic septohippocampal neurons. Psychopharmacology (Berl) 2011; 214:437-54. [PMID: 20959966 DOI: 10.1007/s00213-010-2049-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2010] [Accepted: 10/03/2010] [Indexed: 02/06/2023]
Abstract
INTRODUCTION In rats, activation of medial septum (MS) 5-HT(1A) receptors with the 5-HT(1A)/5-HT(7) receptor agonist 8-OH-DPAT disrupts encoding and consolidation, but not retrieval of a spatial memory in the water maze task. These findings might be explained by an action of 8-OH-DPAT on 5-HT(1A) receptors located on cholinergic neurons which the drug could transiently hyperpolarise. If so, selective damage of these neurons should mimic the effects of 8-OH-DPAT, or, at least, synergistically interfere with them. METHODS To test this hypothesis, rats were subjected to intraseptal infusions of 8-OH-DPAT (or phosphate-buffered saline) during acquisition of a water maze task before and/or after 192 IgG-saporin-induced MS cholinergic lesion (vs. sham-operated). RESULTS We confirmed that only pre-acquisition intraseptal 8-OH-DPAT infusions prevented learning and subsequent drug-free retrieval of the platform location in intact rats and found that (1) the cholinergic lesion did not prevent recall of the platform location, and (2) the impairing effects of 8-OH-DPAT were similar in sham-operated and lesioned rats, whether naïve or not, to the task before lesion surgery. CONCLUSIONS An action of 8-OH-DPAT on only MS cholinergic neurons is not sufficient to account for the drug-induced memory impairments. A concomitant 8-OH-DPAT-induced hyperpolarisation of cholinergic and/or GABAergic and/or glutamatergic neurons (intact rats), or of only GABAergic and/or glutamatergic ones after cholinergic lesion, might be necessary to obliterate task acquisition, confirming that, in the MS, (1) the three neuronal populations could cooperate to process hippocampal-dependent information, and (2) non-cholinergic septohippocampal neurons might be more important than cholinergic ones in serotonin-induced modulation of hippocampus-dependent memory processing.
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Burke SN, Wallace JL, Nematollahi S, Uprety AR, Barnes CA. Pattern separation deficits may contribute to age-associated recognition impairments. Behav Neurosci 2011; 124:559-73. [PMID: 20939657 DOI: 10.1037/a0020893] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Normal aging is associated with impairments in stimulus recognition. In the current investigation, object recognition was tested in adult and aged rats with the standard spontaneous object recognition (SOR) task or two variants of this task. On the standard SOR task, adult rats showed an exploratory preference for the novel object over delays up to 24 h, whereas the aged rats only showed significant novelty discrimination at the 2-min delay. This age difference appeared to be because of the old rats behaving as if the novel object was familiar. To test this hypothesis directly, rats participated in a variant of the SOR task that allowed the exploration times between the object familiarization and the test phases to be compared, and this experiment confirmed that aged rats falsely "recognize" the novel object. A final control examined whether or not aged rats exhibited reduced motivation to explore objects. In this experiment, when the environmental context changed between familiarization and test, young and old rats failed to show an exploratory preference because both age groups spent more time exploring the familiar object. Together these findings support the view that age-related impairments in object recognition arise from old animals behaving as if novel objects are familiar, which is reminiscent of behavioral impairments in young rats with perirhinal cortical lesions. The current experiments thus suggest that alterations in the perirhinal cortex may be responsible for reducing aged animals' ability to distinguish new stimuli from ones that have been encountered previously.
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Affiliation(s)
- Sara N Burke
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85724, USA
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22
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Pompili A, Tomaz C, Arnone B, Tavares MC, Gasbarri A. Working and reference memory across the estrous cycle of rat: A long-term study in gonadally intact females. Behav Brain Res 2010; 213:10-8. [DOI: 10.1016/j.bbr.2010.04.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Revised: 04/08/2010] [Accepted: 04/13/2010] [Indexed: 10/19/2022]
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23
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Gonadal hormones modulate the potency of the disruptive effects of donepezil in male rats responding under a nonspatial operant learning and performance task. Behav Pharmacol 2010; 21:121-34. [PMID: 20177375 DOI: 10.1097/fbp.0b013e328337be3a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In contrast to estrogen in female rats, testosterone in male rats may decrease cholinergic activity in the brain, thereby attenuating behaviors mediated by the cholinergic system. To investigate this possibility, the interactive effects of the gonadal hormones and donepezil, an acetylcholinesterase (AChE) inhibitor, on the responding of male rats were examined under a multiple schedule of repeated acquisition and performance of response sequences and on AChE activity in specific brain regions. Donepezil dose-effect curves (0.56-10 mg/kg) were determined in males that were gonadally intact, gonadectomized (GX), GX with testosterone replacement (GX+T) or GX with estradiol replacement (GX+E). In all four groups, donepezil produced dose-dependent rate-decreasing and error-increasing effects in the acquisition and performance components. However, disruptions of response rate and accuracy in both components occurred at lower doses in GX and GX+E males than in intact males. The GX+E males also had the highest percentage of errors under control (saline) conditions in the acquisition components. In terms of AChE activity, GX males had higher levels in the prefrontal cortex, striatum and hippocampus, but lower levels in the midbrain, compared with intact males; hypothalamic and cortical levels were comparable for the GX and intact groups. Together, these results in male rats indicate that the potency of donepezil's disruptive effects on the responding under a complex operant procedure requiring learning and performance of response sequences depends upon the gonadal hormone status, and that the effects of testosterone on cholinergic activity vary among brain regions.
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Van Kampen JM, Eckman CB. Agonist-induced restoration of hippocampal neurogenesis and cognitive improvement in a model of cholinergic denervation. Neuropharmacology 2009; 58:921-9. [PMID: 20026137 DOI: 10.1016/j.neuropharm.2009.12.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Revised: 12/03/2009] [Accepted: 12/08/2009] [Indexed: 10/20/2022]
Abstract
Loss of basal forebrain cholinergic innervation of the hippocampus and severe neuronal loss within the hippocampal CA1 region are early hallmarks of Alzheimer's disease, and are strongly correlated with cognitive status. Various therapeutic approaches involve attempts to enhance neurotransmission or to provide some level of neuroprotection for remaining cells. An alternative approach may involve the generation of new cells to replace those lost in AD. Indeed, a simple shift in the balance between cell generation and cell loss may slow disease progression and possibly even reverse existing cognitive deficits. One potential neurogenic regulator might be acetylcholine, itself, which has been shown to play a critical role in hippocampal development. Here, we report the effects of various cholinergic compounds on indices of hippocampal neurogenesis, demonstrating a significant induction following pharmacological activation of muscarinic M1 receptors, located on hippocampal progenitors in the adult brain. This is the first report that a small-molecule agonist may induce neurogenesis in the hippocampal CA1 region. Furthermore, such treatment reversed deficits in markers of neurogenesis and spatial working memory triggered by cholinergic denervation in a rodent model. This study suggests the use of small molecule, receptor agonists may represent a novel means to trigger the restoration of specific neuronal populations lost to a variety of neurodegenerative disorders, such as Parkinson's, Alzheimer's, Huntington's and Amyotrophic Lateral Sclerosis.
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George S, Mufson EJ, Leurgans S, Shah RC, Ferrari C, deToledo-Morrell L. MRI-based volumetric measurement of the substantia innominata in amnestic MCI and mild AD. Neurobiol Aging 2009; 32:1756-64. [PMID: 20005600 DOI: 10.1016/j.neurobiolaging.2009.11.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 09/25/2009] [Accepted: 11/08/2009] [Indexed: 11/26/2022]
Abstract
The substantia innominata (SI) contains the nucleus basalis of Meynert, which provides the major cholinergic innervation to the entire cortical mantel and the amygdala; degeneration of nucleus basalis neurons correlates with cognitive decline in Alzheimer's disease (AD). However, whether SI atrophy occurs in individuals with amnestic mild cognitive impairment (aMCI) has not been examined thoroughly in vivo. In the present study, we developed a new protocol to measure volumetric changes in the SI from magnetic resonance imaging (MRI) scans. Participants consisted of 27 elderly controls with no cognitive impairment (NCI); 33 individuals with aMCI; and 19 patients with mild AD. SI volumes were traced on three consecutive gapless 1mm thick coronal slices. Results showed that SI volume was significantly reduced in the mild AD group compared to both NCI and aMCI participants; however, the NCI and aMCI groups did not differ from each other. Furthermore, a decrease in SI volume was related to impaired performance on declarative memory tasks even when attention was controlled.
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Affiliation(s)
- S George
- Department of Neurological Sciences, Rush University Medical Center, 1653 W. Congress Parkway, Chicago, IL 60612, United States
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26
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Bell J, Livesey P, Meyer J. Environmental enrichment influences survival rate and enhances exploration and learning but produces variable responses to the radial maze in old rats. Dev Psychobiol 2009; 51:564-78. [DOI: 10.1002/dev.20394] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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27
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Niewiadomska G, Baksalerska-Pazera M, Riedel G. The septo-hippocampal system, learning and recovery of function. Prog Neuropsychopharmacol Biol Psychiatry 2009; 33:791-805. [PMID: 19389457 DOI: 10.1016/j.pnpbp.2009.03.039] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2009] [Accepted: 03/30/2009] [Indexed: 12/23/2022]
Abstract
We understand this review as an attempt to summarize recent advances in the understanding of cholinergic function in cognition. Such a role has been highlighted in the 1970s by the discovery that dementia patients have greatly reduced cholinergic activity in cortex and hippocampus. A brief anatomical description of the major cholinergic pathways focuses on the basal forebrain and its projections to cortex and hippocampus. From this distinction, compelling evidence suggests that the basal forebrain --> cortex projection regulates the excitability of principal cortical neurons and is thereby critically involved in attention, stimulus detection and memory function, although the biological conditions for these functions are still debated. Similar uncertainties remain for the septo-hippocampal cholinergic system. Although initial lesions of the septum caused memory deficits reminiscent of hippocampal ablations, recent and more refined neurotoxic lesion studies which spared non-cholinergic cells of the basal forebrain failed to confirm these memory impairments in experimental animals despite a near total loss of cholinergic labeling. Yet, a decline in cholinergic markers in aging and dementia still stands as the most central piece of evidence for a link between the cholinergic system and cognition and appear to provide valuable targets for therapeutic approaches.
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von Linstow Roloff E, Harbaran D, Micheau J, Platt B, Riedel G. Dissociation of cholinergic function in spatial and procedural learning in rats. Neuroscience 2007; 146:875-89. [PMID: 17418958 DOI: 10.1016/j.neuroscience.2007.02.038] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2006] [Revised: 12/22/2006] [Accepted: 02/04/2007] [Indexed: 11/25/2022]
Abstract
The cholinergic system has long been known for its role in acquisition and retention of new information. Scopolamine, a muscarinic acetylcholine receptor antagonist impairs multiple memory systems, and this has promoted the notion that drug-induced side effects are responsible for diminished task execution rather than selective impairments on learning and memory per se. Here, we revisit this issue with the aim to dissociate the effects of scopolamine (0.2-1.0 mg/kg) on spatial learning in the water maze. Experiments 1 and 2 showed that acquisition of a reference memory paradigm with constant platform location is compromised by scopolamine independent of whether the animals are pre-trained or not. Deficits were paralleled by drug induced side-effects on sensorimotor parameters. Experiment 3 explored the role of muscarinic receptors in acquisition of an episodic-like spatial delayed matching to position (DMTP) protocol, and scopolamine still caused a learning deficit and side-effects on sensorimotor performance. Rats extensively pre-trained in the DMTP protocol with 30 s and 1 h delays over several months in experiment 4 and tested in a within-subject design under saline and scopolamine had no sensorimotor deficits, but spatial working memory remained compromised. Experiment 5 used the rising Atlantis platform in the DMTP paradigm. Intricate analysis of the amount of dwelling and its location revealed a clear deficit in spatial working memory induced by scopolamine, but there was no effect on sensorimotor or procedural task demands. Apart from the well-known contribution to sensorimotor and procedural learning, our findings provide compelling evidence for an important role of muscarinic acetylcholine receptor signaling in spatial episodic-like memory.
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Affiliation(s)
- E von Linstow Roloff
- School of Medical Sciences, College of Life Science and Medicine, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
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Martin MM, Horn KL, Kusman KJ, Wallace DG. Medial septum lesions disrupt exploratory trip organization: Evidence for septohippocampal involvement in dead reckoning. Physiol Behav 2007; 90:412-24. [PMID: 17126862 DOI: 10.1016/j.physbeh.2006.10.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 09/22/2006] [Accepted: 10/10/2006] [Indexed: 11/21/2022]
Abstract
Rats organize their open field behavior into a series of exploratory trips focused around a central location or home base. In addition, differences in movement kinematics have been used to fractionate the exploratory trip into tour (i.e., sequences of linear movement or progressions punctuated by stops) and homeward (i.e., single progression direct to the home base) segments. The observation of these characteristics independent of environmental familiarity and visual cue availability has suggested a role for self-movement information or dead reckoning in organizing exploratory behavior. Although previous work has implicated a role for the septohippocampal system in dead reckoning based navigation, as of yet, no studies have investigated the contribution of the medial septum to dead reckoning. First, the present study examined the organization of exploratory behavior under dark and light conditions in control rats and rats receiving either electrolytic or sham medial septum lesions. Medial septum lesions produced a significant increase in homeward segment path circuity and variability of temporal pacing of linear speeds. Second, as an independent assessment of the effectiveness of the medial septum lesions, rats were trained to locate a hidden platform in the standard water maze procedure. Consistent with previous research, medial septum lesions attenuated learning the location of the hidden platform. These results demonstrate a role for the medial septum in organizing exploratory behavior and provide further support for the role of the septohippocampal system in dead reckoning based navigation.
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Affiliation(s)
- Megan M Martin
- Psychology Department, Northern Illinois University, De Kalb, Illinois 60115-2892, USA
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30
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Fletcher BR, Baxter MG, Guzowski JF, Shapiro ML, Rapp PR. Selective cholinergic depletion of the hippocampus spares both behaviorally induced Arc transcription and spatial learning and memory. Hippocampus 2007; 17:227-34. [PMID: 17286278 DOI: 10.1002/hipo.20261] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We demonstrated previously that when hippocampal-dependent learning and plasticity are compromised by fornix lesions, behaviorally induced expression of the immediate early gene, Arc, is correspondingly low. The medial septum and the vertical diagonal band are major sources of subcortical afferents that innervate the hippocampus via the fornix. Here we assessed the specific contribution of cholinergic afferents from these regions to the impairments in spatial learning and behavioral induction of Arc transcription produced by fornix lesions. The immunotoxin, 192 IgG-saporin, was used to produce selective lesions of cholinergic cell bodies in the medial septum and vertical diagonal band. Rats were then trained on both cued and spatial delayed match-to-place tasks in a radial arm water maze. Animals with 192 IgG-saporin lesions learned both cue and place discrimination tasks in the water maze normally, and showed only a mild and transient impairment when switching from the cued to the spatial version of the task. Following behavioral testing, rats explored two novel environments sequentially in a setting known to induce Arc expression in hippocampal pyramidal neurons. In marked contrast to the effects of complete fornix transection, quantitative in situ autoradiography revealed no differences in Arc mRNA expression between sham and lesion animals in CA1, CA3 or stratum radiatum. The conclusion from these data is that cholinergic deafferentation alone cannot account for the spatial learning deficits or impaired behavioral induction of Arc transcription produced by fornix lesions.
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Affiliation(s)
- Bonnie R Fletcher
- Fishberg Department of Neuroscience & Alfred B. and Gudrun J. Kastor Neurobiology of Aging Laboratories, Mount Sinai School of Medicine, New York, New York 10029, USA
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31
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Sharifzadeh M, Haghighat A, Tahsili-Fahadan P, Khalaj S, Zarrindast MR, Zamanian AR. Intra-hippocampal inhibition of protein kinase AII attenuates morphine-induced conditioned place preference. Pharmacol Biochem Behav 2006; 85:705-12. [PMID: 17174386 DOI: 10.1016/j.pbb.2006.10.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Revised: 10/29/2006] [Accepted: 10/31/2006] [Indexed: 11/16/2022]
Abstract
Morphine and other drugs of abuse modulate protein kinase A (PKA) signaling within the mesolimbic reward pathway. Using a balanced conditioned place preference (CPP) paradigm, we studied the possible involvement of protein kinase AII (PKA II) on the acquisition, expression and consolidation of morphine place conditioning in male Wistar rats. Subcutaneous administration of various doses of morphine sulfate (1-9 mg/kg) induced CPP in a dose-dependent manner. H-89, a selective PKA II inhibitor, was administered into CA1 region of the hippocampus at 1, 2.5 and 5 microM/rat. Using a 3-day schedule of conditioning, it was found that the H-89 did not produce a significant place preference or place aversion. H-89 (1, 2.5 and 5 microM/rat) significantly reduced the time spent by rats in the morphine compartment when given immediately after each conditioning session (consolidation), whereas it had no effect when administered before morphine during the conditioning phase (acquisition) or before testing for place preference in the absence of morphine (expression). It is concluded that the PKA II may play an active role in the consolidation of reward-related memory of morphine in CA1 region of the hippocampus.
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Affiliation(s)
- Mohammad Sharifzadeh
- Department of Pharmacology and Toxicology, Medicinal Plants and Pharmaceutical Sciences Research Centers, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
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Frielingsdorf H, Thal LJ, Pizzo DP. The septohippocampal cholinergic system and spatial working memory in the Morris water maze. Behav Brain Res 2006; 168:37-46. [PMID: 16330106 DOI: 10.1016/j.bbr.2005.10.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2005] [Revised: 09/30/2005] [Accepted: 10/10/2005] [Indexed: 11/30/2022]
Abstract
The objective of the present study was to determine whether a systematic optimization of Morris water maze (mwm) testing parameters could reveal a significant role of the septohippocampal cholinergic system in spatial working memory. Young adult rats were lesioned using 192 IgG-saporin infused bilaterally into the medial septum. Lesions were near complete as measured by choline acetyltransferase (ChAT) activity and immunohistochemistry. Behavioral testing was performed in three phases. In the first, lesioned and unlesioned rats were trained in the mwm focusing on working memory, which was tested using novel platform locations daily. In the second phase, the optimal locations were retested with increasing intertrial intervals (ITI). In the third phase, intracerebroventricular infusions of nerve growth factor (NGF) were employed to enhance cholinergic activity of the unlesioned rats and potentially further separate group performance. Neither the standard or increased ITI resulted in a consistent significant difference in spatial working memory between groups. In addition, NGF treatment also failed to induce a significant difference in behavioral performance. In conclusion, impairments in working memory as assessed by the mwm could not be revealed despite a greater than 90% loss of hippocampal ChAT and the use of optimal testing parameters and NGF treatment.
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Affiliation(s)
- Helena Frielingsdorf
- Department of Neurosciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0624, USA
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Chrobak JJ, Sabolek HR, Bunce JG. Intraseptal cholinergic infusions alter memory in the rat: method and mechanism. EXS 2006; 98:87-98. [PMID: 17019884 DOI: 10.1007/978-3-7643-7772-4_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Affiliation(s)
- James J Chrobak
- Department of Psychology, University of Connecticut, Storrs, CT 06269, USA.
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Wietrzych M, Meziane H, Sutter A, Ghyselinck N, Chapman PF, Chambon P, Krezel W. Working memory deficits in retinoid X receptor gamma-deficient mice. Learn Mem 2005; 12:318-26. [PMID: 15897255 PMCID: PMC1142461 DOI: 10.1101/lm.89805] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Retinoid signaling has been recently shown to be required for mnemonic functions in rodents. To dissect the behavioral and molecular mechanisms involved in this requirement, we have analyzed the spatial and recognition working memory in mice carrying null mutations of retinoid receptors RARbeta and RXRgamma. Double mutants appeared deficient in spatial working memory as tested in spontaneous alternation in the Y-maze and delayed nonmatch to place (DNMTP) test in the T-maze. These mutant mice did acquire, however, spatial place reference or right/left discrimination tasks in the T-maze set-up, indicating that basic sensorimotor functions, spatial orientation, and motivational factors are unlikely to account for deficits in working memory-sensitive tasks. Double-mutant mice were also deficient in novel object recognition at intermediate, but not short delays. RXRgamma appeared to be the functionally predominant receptor in modulation of the working memory, as RXRgamma, but not RARbeta single null mutant mice exhibited deficits similar to those observed in the double mutants. The mechanism of this modulation is potentially related to functions of RXRgamma in frontal and perirhinal cortex, structures in which we detected RXRgamma expression and which are functionally implicated in working memory processes.
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Affiliation(s)
- Marta Wietrzych
- Institut de Gaénétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut Clinique de la Souris (ICS), CNRS/INSERM/ULP, College de France, BP10142, 67404 Illkirch Cedex, CU de Strasbourg, France
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35
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Sarter M, Bruno JP. Developmental origins of the age-related decline in cortical cholinergic function and associated cognitive abilities. Neurobiol Aging 2004; 25:1127-39. [PMID: 15312959 DOI: 10.1016/j.neurobiolaging.2003.11.011] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2003] [Revised: 10/01/2003] [Accepted: 11/14/2003] [Indexed: 10/26/2022]
Abstract
Ontogenetic abnormalities in the regulation of the cortical cholinergic input system are hypothesized to mediate early-life cognitive limitations (ECL) that later escalate, based on reciprocal interactions between a dysregulated cholinergic system and age-related neuronal and vascular processes, to mild cognitive impairment (MCI) and, subsequently, for a majority of subjects, senile dementia. This process is speculated to begin with the disruption of trophic factor support of the basal forebrain ascending cholinergic system early in life, leading to dysregulation of cortical cholinergic transmission during the initial decades of life and associated limitations in cognitive capacities. Results from neurochemical and behavioral experiments support the possibility that aging reveals the vulnerability of an abnormally regulated cortical cholinergic input system. The decline of the cholinergic system is further accelerated as a result of interactions with amyloid precursor protein metabolism and processing, and with cerebral microvascular abnormalities. The determination of the developmental variables that render the cortical cholinergic input system vulnerable to age-related processes represents an important step toward the understanding of the role of this neuronal system in the age-related decline in cognitive functions.
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Affiliation(s)
- Martin Sarter
- Departments of Psychology and Neuroscience, Ohio State University, 27 Townshend Hall, 1885 Neil Avenue, Columbus, OH 43210, USA.
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36
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Winters BD, Dunnett SB. Selective lesioning of the cholinergic septo-hippocampal pathway does not disrupt spatial short-term memory: a comparison with the effects of fimbria-fornix lesions. Behav Neurosci 2004; 118:546-62. [PMID: 15174932 DOI: 10.1037/0735-7044.118.3.546] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Rats receiving intrahippocampal injections of 192 IgG-saporin (SAP-HPC), fimbria-fornix lesions (FF), or sham control surgeries were tested in a series of delayed matching (DMTP)- and nonmatching (DNMTP)-to-position tasks. The FF group was significantly impaired on a pretrained DNMTP task relative to the control and SAP-HPC groups, which did not differ. All groups then acquired a matching-to- position rule at the same rate, and only the FF group showed a delay-dependent deficit when longer retention intervals were introduced for DMTP testing. Results demonstrate the importance of the fimbria-fornix fiber system in spatial short-term memory but suggest that the cholinergic septohippocampal component of this pathway is not required for successful delayed matching (or nonmatching)-to-position performance.
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Affiliation(s)
- Boyer D Winters
- Medical Research Council Cambridge Centre for Brain Repair, and Departmernt of Experimental Psychology, University of Cambridge, Downing Street, Cambridge CB2 3EB, United Kingdom.
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37
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Vuckovich JA, Semel ME, Baxter MG. Extensive lesions of cholinergic basal forebrain neurons do not impair spatial working memory. Learn Mem 2004; 11:87-94. [PMID: 14747521 PMCID: PMC321318 DOI: 10.1101/lm.63504] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A recent study suggests that lesions to all major areas of the cholinergic basal forebrain in the rat (medial septum, horizontal limb of the diagonal band of Broca, and nucleus basalis magnocellularis) impair a spatial working memory task. However, this experiment used a surgical technique that may have damaged cerebellar Purkinje cells. The present study tested rats with highly selective lesions of cholinergic neurons in all major areas of the basal forebrain on a spatial working memory task in the radial arm maze. In postoperative testing, there were no significant differences between lesion and control groups in working memory, even with a delay period of 8 h, with the exception of a transient impairment during the first 2 d of postoperative testing at shorter delays (0 or 2 h). This finding corroborates other results that indicate that the cholinergic basal forebrain does not play a significant role in spatial working memory. Furthermore, it underscores the presence of intact memory functions after cholinergic basal forebrain damage, despite attentional impairments that follow these lesions, demonstrated in other task paradigms.
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Affiliation(s)
- Joseph A Vuckovich
- Department of Psychology, Harvard University, Cambridge, Massachusetts 02138, USA
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Parent MB, Baxter MG. Septohippocampal acetylcholine: involved in but not necessary for learning and memory? Learn Mem 2004; 11:9-20. [PMID: 14747512 PMCID: PMC1668717 DOI: 10.1101/lm.69104] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The neurotransmitter acetylcholine (ACh) has been accorded an important role in supporting learning and memory processes in the hippocampus. Cholinergic activity in the hippocampus is correlated with memory, and restoration of ACh in the hippocampus after disruption of the septohippocampal pathway is sufficient to rescue memory. However, selective ablation of cholinergic septohippocampal projections is largely without effect on hippocampal-dependent learning and memory processes. We consider the evidence underlying each of these statements, and the contradictions they pose for understanding the functional role of hippocampal ACh in memory. We suggest that although hippocampal ACh is involved in memory in the intact brain, it is not necessary for many aspects of hippocampal memory function.
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Affiliation(s)
- Marise B Parent
- Department of Psychology and Center for Behavioral Neuroscience, Georgia State University, Atlanta, Georgia 30303, USA.
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39
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Pepeu G, Giovannini MG. Changes in acetylcholine extracellular levels during cognitive processes. Learn Mem 2004; 11:21-7. [PMID: 14747513 DOI: 10.1101/lm.68104] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Measuring the changes in neurotransmitter extracellular levels in discrete brain areas is considered a tool for identifying the neuronal systems involved in specific behavioral responses or cognitive processes. Acetylcholine (ACh) is the first neurotransmitter whose diffusion from the central nervous system was investigated and whose extracellular levels variations were correlated to changes in neuronal activity. This was done initially by means of the cup technique and then by the microdialysis technique. The latter, notwithstanding some technical limitations, makes it possible to detect variations in extracellular levels of ACh in unrestrained, behaving animals. This review summarizes and discusses the results obtained investigating the changes in ACh release during performance of operant tasks, exposition to novel stimuli, locomotor activity, and the performance of spatial memory tasks, working memory, and place preference memory tasks. Activation of the forebrain cholinergic system has been demonstrated in many tasks and conditions in which the environment requires the animal to analyze novel stimuli that may represent a threat or offer a reward. The sustained cholinergic activation, demonstrated by high levels of extracellular ACh observed during the behavioral paradigms, indicates that many behaviors occur within or require the facilitation provided by the cholinergic system to the operation of pertinent neuronal pathways.
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Affiliation(s)
- Giancarlo Pepeu
- Department of Pharmacology, University of Florence, 50139 Florence, Italy.
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40
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Sarter M, Bruno JP, Givens B. Attentional functions of cortical cholinergic inputs: what does it mean for learning and memory? Neurobiol Learn Mem 2004; 80:245-56. [PMID: 14521867 DOI: 10.1016/s1074-7427(03)00070-4] [Citation(s) in RCA: 220] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The hypothesis that cortical cholinergic inputs mediate attentional functions and capacities has been extensively substantiated by experiments assessing the attentional effects of specific cholinotoxic lesions of cortical cholinergic inputs, attentional performance-associated cortical acetylcholine release, and the effects of pharmacological manipulations of the excitability of basal forebrain corticopetal cholinergic projections on attentional performance. At the same time, numerous animal experiments have suggested that the integrity of cortical cholinergic inputs is not necessary for learning and memory, and a dissociation between the role of the cortical cholinergic input system in attentional functions and in learning and memory has been proposed. We speculate that this dissociation is due, at least in part, to the use of standard animal behavioral tests for the assessment of learning and memory which do not sufficiently tax defined attentional functions. Attentional processes and the allocation of attentional capacities would be expected to influence the efficacy of the acquisition and recall of declarative information and therefore, persistent abnormalities in the regulation of the cortical cholinergic input system may yield escalating impairments in learning and memory. Furthermore, the cognitive effects of loss of cortical cholinergic inputs are augmented by the disruption of the top-down regulation of attentional functions that normally acts to optimize information processing in posterior cortical areas. Because cortical cholinergic inputs play an integral role in the mediation of attentional processing, the activity of cortical cholinergic inputs is hypothesized to also determine the efficacy of learning and memory.
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Affiliation(s)
- Martin Sarter
- Departments of Psychology and Neuroscience, The Ohio State University, Columbus, OH 43210, USA.
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41
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Janisiewicz AM, Jackson O, Firoz EF, Baxter MG. Environment-spatial conditional learning in rats with selective lesions of medial septal cholinergic neurons. Hippocampus 2004; 14:265-73. [PMID: 15098731 DOI: 10.1002/hipo.10175] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Cholinergic medial septal neurons may regulate several aspects of hippocampal function, including place field stability and spatial working memory. Monkeys with damage to septal cholinergic neurons are impaired in visual-spatial conditional learning tasks; however, this candidate function of septal cholinergic neurons has not been studied extensively in the rat. In the present study, rats with selective lesions of cholinergic neurons in the medial septum and vertical limb of the diagonal band of Broca (MS/VDB), made with 192 IgG-saporin, were tested on a conditional associative learning task. In this task, which we term "environment-spatial" conditional learning, the correct location of a spatial response depended on the array of local environmental cues. MS/VDB-lesioned rats were impaired when the two parts of the conditional problem were presented concurrently, but not when one environment had been learned before the full conditional problem was presented. Our findings suggest that cholinergic MS/VDB neurons participate in some aspects of conditional associative learning in rats. They may also shed light on the involvement of cholinergic projections to the hippocampus in modulating and remodeling hippocampal spatial representations.
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42
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Bizon JL, Han JS, Hudon C, Gallagher M. Effects of hippocampal cholinergic deafferentation on learning strategy selection in a visible platform version of the water maze. Hippocampus 2003; 13:676-84. [PMID: 12962313 DOI: 10.1002/hipo.10113] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Recent evidence has suggested that the relative levels of acetylcholine (ACh) between brain structures may be an important factor in the choice of behavioral strategy in settings in which either hippocampal or dorsal striatal brain systems can be employed both effectively and independently (McIntyre and Gold. 1999. Soc Neurosci Abs 25:1388). The current investigation used the neurotoxin 192 IgG-saporin to deplete the hippocampus of ACh selectively, while leaving ACh in other brain regions, including dorsal striatum, intact. Rats were then trained on a version of the Morris water maze, in which behavioral strategies attributed to the hippocampus and dorsal striatum are placed in direct competition. It was predicted that rats with hippocampal ACh depletion would display a cue bias. Contrary to this prediction, depleting hippocampal ACh did not bias against and, in fact, promoted use of a hippocampal place strategy in this task, as indicated by choice in competition tests and performance on hidden platform training trials. These data add to a growing literature demonstrating that the septohippocampal cholinergic system is not required for accurate spatial learning and suggest a complex role for basal forebrain projections in processing information about the spatial environment.
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Affiliation(s)
- J L Bizon
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland 21218, USA.
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43
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Wolff M, Benhassine N, Costet P, Hen R, Segu L, Buhot MC. Delay-dependent working memory impairment in young-adult and aged 5-HT1BKO mice as assessed in a radial-arm water maze. Learn Mem 2003; 10:401-9. [PMID: 14557613 PMCID: PMC218006 DOI: 10.1101/lm.60103] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Serotonin (5-HT) plays a modulatory role in mnemonic functions, especially by interacting with the cholinergic system. The 5-HT1B receptor is a key target of this interaction. The 5-HT1B receptor knockout mice were found previously to exhibit a facilitation in hippocampal-dependent spatial reference memory learning. In the present study, we submitted mice to a delayed spatial working memory task, allowing the introduction of various delays between an exposure trial and a test trial. The 5-HT1BKO and wild-type mice learned the task in a radial-arm water maze (returning to the most recent presented arm containing the escape platform), and exhibited a high level of performance at delays of 0 and 5 min. However, at the delay of 60 min, only 5-HT1BKO mice exhibited an impairment. At a delay of 90 min, all mice were impaired. Treatment by scopolamine (0.8 mg/kg) induced the same pattern of performance in wild type as did the mutation for short (5 min, no impairment) and long (60 min, impairment) delays. The 22-month-old wild-type and knockout mice exhibited an impairment at short delays (5 and 15 min). The effect of the mutation affected both young-adult and aged mice at delays of 15, 30, and 60 min. Neurobiological data show that stimulation of the 5-HT1B receptor inhibits the release of acetylcholine in the hippocampus, but stimulates this in the frontal cortex. This dual function might, at least in part, explain the opposite effect of the mutation on reference memory (facilitation) and delay-dependent working memory (impairment). These results support the idea that cholinergic-serotonergic interactions play an important role in memory processes.
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Affiliation(s)
- Mathieu Wolff
- Centre National de la Recherche Scientifique-UMR 5106, Laboratoire de Neurosciences Cognitives, Universitéde Bordeaux 1, 33405 Talence cedex, France
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44
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Buhot MC, Wolff M, Benhassine N, Costet P, Hen R, Segu L. Spatial Learning in the 5-HT1B Receptor Knockout Mouse: Selective Facilitation/Impairment Depending on the Cognitive Demand. Learn Mem 2003; 10:466-77. [PMID: 14657258 DOI: 10.1101/lm.60203] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Age-related memory decline is associated with a combined dysfunction of the cholinergic and serotonergic systems in the hippocampus and frontal cortex, in particular. The 5-HT1B receptor occupies strategic cellular and subcellular locations in these structures, where it plays a role in the modulation of ACh release. In an attempt to characterize the contribution of this receptor to memory functions, 5-HT1B receptor knockout (KO) mice were submitted to various behavioral paradigms carried out in the same experimental context (water maze), which were aimed at exposing mice to various levels of memory demand. 5-HT1BKO mice exhibited a facilitation in the acquisition of a hippocampal-dependent spatial reference memory task in the Morris water maze. This facilitation was selective of task difficulty, showing thus that the genetic inactivation of the 5-HT1B receptor is associated with facilitation when the complexity of the task is increased, and reveals a protective effect on age-related hippocampal-dependent memory decline. Young-adult and aged KO and wild-type (WT) mice were equally able to learn a delayed spatial matching-to-sample working memory task in a radial-arm water maze with short (0 or 5 min) delays. However, 5-HT1BKO mice, only, exhibited a selective memory impairment at intermediate and long (15, 30, and 60 min) delays. Treatment by scopolamine induced the same pattern of performance in wild type as did the mutation for short (5 min, no impairment) and long (60 min, impairment) delays. Taken together, these studies revealed a beneficial effect of the mutation on the acquisition of a spatial reference memory task, but a deleterious effect on a working memory task for long delays. This 5-HT1BKO mouse story highlights the problem of the potential existence of "global memory enhancers."
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Affiliation(s)
- Marie-Christine Buhot
- Centre National de la Recherche Scientifique-Unité Mixte de Recherche 5106, Laboratoire de Neurosciences Cognitives, Université de Bordeaux 1, 33405 Talence, France.
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45
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Lehmann O, Grottick AJ, Cassel JC, Higgins GA. A double dissociation between serial reaction time and radial maze performance in rats subjected to 192 IgG-saporin lesions of the nucleus basalis and/or the septal region. Eur J Neurosci 2003; 18:651-66. [PMID: 12911761 DOI: 10.1046/j.1460-9568.2003.02745.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The cholinergic basal forebrain has been implicated in aspects of cognitive function including memory and attention, but the precise contribution of its major components, the basalocortical and the septohippocampal systems, remains unclear. Rats were subjected to lesions of either the nucleus basalis magnocellularis (Basalis), the medial septum/vertical limb of the diagonal band of Broca (Septum), or both nuclei (Basalis + Septum), using the selective cholinotoxin 192 IgG-saporin. Cognitive performance was evaluated in tasks taxing attention (the five-choice serial reaction time task, 5-CSRTT) and spatial working memory (radial arm maze, RAM). Nucleus basalis lesions disrupted performance of the 5-CSRTT, as demonstrated by decreased choice accuracy, increased incidence of missed trials, increased latencies to respond correctly, and a disrupted pattern of response control. Combined lesions of the Basalis and Septum resulted in qualitatively similar deficits to Basalis lesions alone, although interestingly, these rats were unimpaired on measures of response speed, and showed weaker deficits on accuracy and omissions. Decreasing the attentional load by lengthening stimulus duration reversed some of the deficits in Basalis and Basalis + Septum rats, suggesting an attentional deficit rather than motivation or motor perturbations. Performance in rats with septal lesions was only affected when task difficulty was increased. In the RAM an opposing pattern of effects was observed, with Septum and Basalis + Septum rats showing dramatic impairments, and Basalis rats performing normally. Taken together, these data provide clear evidence for a functional dissociation between septohippocampal and basalocortical cholinergic systems in aspects of cognitive function.
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Affiliation(s)
- O Lehmann
- LN2C, UMR 7521 CNRS/Université Louis Pasteur, 12 rue Goethe, F-67000 Strasbourg, France
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46
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Kirby BP, Rawlins JNP. The role of the septo-hippocampal cholinergic projection in T-maze rewarded alternation. Behav Brain Res 2003; 143:41-8. [PMID: 12842294 DOI: 10.1016/s0166-4328(03)00005-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Administration of 192IgG-saporin, a cholinergic neurotoxin, to the medial septum destroys the cell bodies from which the septo-hippocampal cholinergic projection originates, leading to reductions in both hippocampal acetylcholinesterase (AChE) and choline acetyltransferase (ChAT). Despite reports that 192IgG-saporin-induced cholinergic loss leads to post-operative impairments in acquisition and performance of spatial memory tasks, a number of other reports have described intact spatial memory performance following these lesions. Factors that might account for these different outcomes include variations in toxin injection sites or volumes, and post-operative testing at times that might permit regeneration of damaged neuronal processes. We, therefore, assessed the effects of intraseptal microinjection of 192IgG-saporin, in rats, on the post-operative retention of pre-operatively acquired discrete-trial rewarded alternation in the T-maze. This design allowed us to assess the effects of the lesion 7 days post-surgery, at which point, at best, incomplete neuronal regeneration would have been expected to have occurred. The lesion led to a profound loss of hippocampal AChE staining, and a clear inflammatory response, as assessed by proliferation of OX42-stained macrophages in the medial septum and diagonal band nuclei, but there was no impairment in spatial working memory.
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Affiliation(s)
- B P Kirby
- Department of Experimental Psychology, University of Oxford, South Parks Road, OX1 3UD, England, Oxford, UK.
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47
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Torras-Garcia M, Costa-Miserachs D, Morgado-Bernal I, Portell-Cortés I. Improvement of shuttle-box performance by anterodorsal medial septal lesions in rats. Behav Brain Res 2003; 141:147-58. [PMID: 12742251 DOI: 10.1016/s0166-4328(02)00346-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Septal lesions impair a variety of tasks, including inhibitory avoidance and one way active avoidance. In contrast, these lesions improve two-way active avoidance, probably by reducing anxiety. The present work aimed to study whether anterodorsal medial septal lesion (a) improves performance of two-way active avoidance task (Experiment I), as it has been observed with wider septal lesion, and (b) affect anxiety and/or locomotor activity (Experiment II). This precise region was chosen because some evidences suggest that its lesion do not lead to a reduction of anxiety. Lesioned rats tended to make a higher, but statistically non-significant (P=0.074), number of avoidances regardless of the session, being this difference statistically significant on the retention session (RT). The same lesion did not appear to have an anxiolytic effect, and did not affected basal locomotor activity. Different possible explanations of our results are discussed.
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Affiliation(s)
- Meritxell Torras-Garcia
- Departament de Psicobiologia i de Metodologia de les Ciències de la Salut, Facultat de Psicologia, Edifici B, Universitat Autònoma de Barcelona, 08193-Bellaterra, Barcelona, Spain
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48
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Lamprea MR, Cardenas FP, Silveira R, Walsh TJ, Morato S. Effects of septal cholinergic lesion on rat exploratory behavior in an open-field. Braz J Med Biol Res 2003; 36:233-8. [PMID: 12563526 DOI: 10.1590/s0100-879x2003000200011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The medial septum participates in the modulation of exploratory behavior triggered by novelty. Also, selective lesions of the cholinergic component of the septohippocampal system alter the habituation of rats to an elevated plus-maze without modifying anxiety indices. We investigated the effects of the intraseptal injection of the cholinergic immunotoxin 192 IgG-saporin (SAP) on the behavior of rats in an open-field. Thirty-nine male Wistar rats (weight: 194-230 g) were divided into three groups, non-injected controls and rats injected with either saline (0.5 microl) or SAP (237.5 ng/0.5 microl). Twelve days after surgery, the animals were placed in a square open-field (120 cm) and allowed to freely explore for 5 min. After the test, the rats were killed by decapitation and the septum, hippocampus and frontal cortex were removed and assayed for acetylcholinesterase activity. SAP increased acetylcholinesterase activity in the septum, hippocampus and frontal cortex and decreased the total distance run (9.15 +/- 1.51 m) in comparison to controls (13.49 +/- 0.91 m). The time spent in the center and at the periphery was not altered by SAP but the distance run was reduced during the first and second minutes (2.43 +/- 0.36 and 1.75 +/- 0.34 m) compared to controls (4.18 +/- 0.26 and 3.14 +/- 0.25 m). SAP-treated rats showed decreased but persistent exploration throughout the session. These results suggest that septohippocampal cholinergic mechanisms contribute to at least two critical processes, one related to the motivation to explore new environments and the other to the acquisition and storage of spatial information (i.e., spatial memory).
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Affiliation(s)
- M R Lamprea
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
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49
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Ikonen S, McMahan R, Gallagher M, Eichenbaum H, Tanila H. Cholinergic system regulation of spatial representation by the hippocampus. Hippocampus 2002; 12:386-97. [PMID: 12099489 DOI: 10.1002/hipo.1109] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The role of the basal forebrain cholinergic system in hippocampal spatial representation was explored by examining the effects of immunotoxic lesions of the septo-hippocampal cholinergic neurons on the firing patterns of hippocampal place cells as rats explored familiar and novel environments. In a highly familiar environment, the basic qualities and stability of place fields were unaffected by the lesion. When first exposed to a set of novel environmental cues without otherwise disorienting the animals, place cells in both normal and lesioned animals responded with similar alterations in their firing patterns. Upon subsequent repetitive exposures to the new environment, place cells of normal rats developed a spatial representation distinct from that of the familiar environment. By contrast, place cells of lesioned animals reconverged in the direction of the representation associated with the familiar environment. These results suggest that cholinergic input may determine whether new visual information or a stored representation of the current environment will be actively processed in the hippocampal network.
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Affiliation(s)
- Sami Ikonen
- Department of Neuroscience and Neurology, University and University Hospital of Kuopio, Finland
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Gibbs RB. Basal forebrain cholinergic neurons are necessary for estrogen to enhance acquisition of a delayed matching-to-position T-maze task. Horm Behav 2002; 42:245-57. [PMID: 12460585 DOI: 10.1006/hbeh.2002.1825] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Intraseptal injections of the selective cholinergic immunotoxin 192 IgG-saporin (SAP) were performed to determine whether basal forebrain cholinergic neurons are necessary for hormone-mediated enhancement of acquisition in a delayed matching-to-position (DMP) T-maze task. The DMP task is a simple spatial learning task. Studies have shown that continuous estradiol replacement enhances acquisition of the DMP task in young ovariectomized rats and that long-term treatment with either estradiol or estradiol + progesterone can prevent a deficit in DMP acquisition in old rats. In the present study, continuous estradiol replacement significantly enhanced acquisition of the DMP task by non-SAP-treated, ovariectomized rats. In contrast, neither continuous estradiol nor weekly administration of estradiol + progesterone significantly enhanced acquisition of the DMP task in rats that received intraseptal injections of either a high dose (1.0 microg) or a low dose (0.22 microg) of SAP. Animals that reached criterion were significantly impaired by rotating the maze 180 degrees regardless of treatment, suggesting that animals in all groups used extramaze cues to at least some degree to solve the task. SAP-treated animals were slightly more sensitive to increasing the intertrial delay than non-SAP-treated controls, suggesting that the SAP lesions produced a modest deficit in spatial working memory. Immunohistochemistry confirmed the loss of cholinergic neurons in specific regions of the basal forebrain of SAP-treated animals. In addition, DMP acquisition correlated significantly with ChAT activity in the hippocampus and frontal cortex. The data suggest that basal forebrain cholinergic projections are necessary for hormone-mediated enhancement of DMP acquisition.
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Affiliation(s)
- Robert B Gibbs
- Department of Pharmaceuticl Sciences, University of Pittsburg School of Pharmacy, Pennsylvania 15261, USA.
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