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Potier M, Maitre M, Leste-Lasserre T, Marsicano G, Chaouloff F, Marighetto A. Age-dependent effects of estradiol on temporal memory: A role for the type 1 cannabinoid receptor? Psychoneuroendocrinology 2023; 148:106002. [PMID: 36521252 DOI: 10.1016/j.psyneuen.2022.106002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 12/07/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022]
Abstract
This study investigated in male mice how age modulates the effects of acute 17β-estradiol (E2) on dorsal CA1 (dCA1)-dependent retention of temporal associations, which are critical for declarative memory. E2 was systemically injected to young (3-4 months old) and aged (22-24 months old) adult mice either (i) 1 h before the acquisition of an auditory trace fear conditioning (TFC) procedure allowing the assessment of temporal memory retention 24 h later or (ii) during in vivo electrophysiological recordings of CA3 to dCA1 synaptic efficacy under anesthesia. In young mice, E2 induced parallel dose-dependent reductions in memory and synaptic efficacy, i.e. an impairment in TFC retention and a long-term (NMDA receptor-dependent) depression of dCA1 synaptic efficacy as assessed by field excitatory postsynaptic potentials. In contrast, E2 tended to improved TFC retention whilst failing to change synaptic efficacy in aged mice. Age-dependent effects of E2 treatment were confirmed by immunohistochemical analyses of TFC acquisition-elicited dCA1 Fos activation. Thus, such an activation was respectively reduced and enhanced in young and aged E2-treated mice, compared to vehicle treatments. Hippocampal mRNA expression of estrogen receptors by RT-PCR analyses revealed an age-related increase in each receptor mRNA expression. In keeping with the key role of the endocannabinoid system in memory processes and CA3 to dCA1 synaptic plasticity, we next examined the role of cannabinoid type 1 receptors (CB1-R) in the aforementioned age-dependent effects of E2. Having confirmed that mRNA expression of CB1-R diminishes with age, we then observed that the deleterious effects of E2 on both memory and synaptic efficacy were both prevented by the CB1-R antagonist Rimonabant whilst being absent in CB1-R knock out mice. This study (i) reveals age-dependent effects of acute E2 on temporal memory and CA3 to dCA1 synaptic efficacy and (ii) suggests a key role of CB1-R in mediating E2 deleterious effects in young adulthood. Aging-related reductions in CB1-R might thus underlie E2 paradoxical effects across age.
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Affiliation(s)
- Mylène Potier
- Pathophysiology of Declarative Memory, INSERM U1215, Neurocentre Magendie, Bordeaux, France; University of Bordeaux, Bordeaux, France.
| | - Marlène Maitre
- PUMA, INSERM U1215, Neurocentre Magendie, Bordeaux, France
| | | | - Giovanni Marsicano
- Endocannabinoids & NeuroAdaptation, INSERM U1215, Neurocentre Magendie, Bordeaux, France; University of Bordeaux, Bordeaux, France
| | - Francis Chaouloff
- Endocannabinoids & NeuroAdaptation, INSERM U1215, Neurocentre Magendie, Bordeaux, France; University of Bordeaux, Bordeaux, France.
| | - Aline Marighetto
- Pathophysiology of Declarative Memory, INSERM U1215, Neurocentre Magendie, Bordeaux, France; University of Bordeaux, Bordeaux, France
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Al Abed AS, Sellami A, Potier M, Ducourneau E, Gerbeaud‐Lassau P, Brayda‐Bruno L, Lamothe V, Sans N, Desmedt A, Vanhoutte P, Bennetau‐Pelissero C, Trifilieff P, Marighetto A. Age-related impairment of declarative memory: linking memorization of temporal associations to GluN2B redistribution in dorsal CA1. Aging Cell 2020; 19:e13243. [PMID: 33009891 PMCID: PMC7576225 DOI: 10.1111/acel.13243] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 08/10/2020] [Accepted: 08/26/2020] [Indexed: 01/23/2023] Open
Abstract
GluN2B subunits of NMDA receptors have been proposed as a target for treating age-related memory decline. They are indeed considered as crucial for hippocampal synaptic plasticity and hippocampus-dependent memory formation, which are both altered in aging. Because a synaptic enrichment in GluN2B is associated with hippocampal LTP in vitro, a similar mechanism is expected to occur during memory formation. We show instead that a reduction of GluN2B synaptic localization induced by a single-session learning in dorsal CA1 apical dendrites is predictive of efficient memorization of a temporal association. Furthermore, synaptic accumulation of GluN2B, rather than insufficient synaptic localization of these subunits, is causally involved in the age-related impairment of memory. These challenging data identify extra-synaptic redistribution of GluN2B-containing NMDAR induced by learning as a molecular signature of memory formation and indicate that modulating GluN2B synaptic localization might represent a useful therapeutic strategy in cognitive aging.
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Affiliation(s)
- Alice Shaam Al Abed
- INSERMNeurocentre MagendieBordeauxFrance
- Neurocentre MagendieBordeaux UniversityBordeauxFrance
- Bordeaux Sciences AgroBordeauxFrance
- Present address:
Eccles Institute of NeuroscienceJohn Curtin School of Medical ResearchThe Australian National UniversityCanberraACTAustralia
| | - Azza Sellami
- INSERMNeurocentre MagendieBordeauxFrance
- Neurocentre MagendieBordeaux UniversityBordeauxFrance
| | - Mylene Potier
- INSERMNeurocentre MagendieBordeauxFrance
- Bordeaux Sciences AgroBordeauxFrance
| | - Eva‐Gunnel Ducourneau
- INSERMNeurocentre MagendieBordeauxFrance
- Neurocentre MagendieBordeaux UniversityBordeauxFrance
| | - Pauline Gerbeaud‐Lassau
- INSERMNeurocentre MagendieBordeauxFrance
- Neurocentre MagendieBordeaux UniversityBordeauxFrance
| | - Laurent Brayda‐Bruno
- INSERMNeurocentre MagendieBordeauxFrance
- Neurocentre MagendieBordeaux UniversityBordeauxFrance
| | - Valerie Lamothe
- INSERMNeurocentre MagendieBordeauxFrance
- Bordeaux Sciences AgroBordeauxFrance
| | - Nathalie Sans
- INSERMNeurocentre MagendieBordeauxFrance
- Neurocentre MagendieBordeaux UniversityBordeauxFrance
| | - Aline Desmedt
- INSERMNeurocentre MagendieBordeauxFrance
- Neurocentre MagendieBordeaux UniversityBordeauxFrance
| | - Peter Vanhoutte
- Institute of Biology Paris SeineINSERMUMR‐S1130Neuroscience Paris SeineParisFrance
- CNRSUMR 8246Neuroscience Paris SeineParisFrance
- UPMC Université Paris 06UM CR18Neuroscience Paris SeineSorbonne UniversitéParisFrance
| | | | | | - Aline Marighetto
- INSERMNeurocentre MagendieBordeauxFrance
- Neurocentre MagendieBordeaux UniversityBordeauxFrance
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Fritz HJ, Ray N, Dyrba M, Sorg C, Teipel S, Grothe MJ. The corticotopic organization of the human basal forebrain as revealed by regionally selective functional connectivity profiles. Hum Brain Mapp 2019; 40:868-878. [PMID: 30311315 PMCID: PMC6865372 DOI: 10.1002/hbm.24417] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 08/06/2018] [Accepted: 10/01/2018] [Indexed: 12/25/2022] Open
Abstract
The cholinergic basal forebrain (CBF), comprising different groups of cortically projecting cholinergic neurons, plays a crucial role in higher cognitive processes and has been implicated in diverse neuropsychiatric disorders. A distinct corticotopic organization of CBF projections has been revealed in animal studies, but little is known about their organization in the human brain. We explored regional differences in functional connectivity (FC) profiles within the human CBF by applying a clustering approach to resting-state functional magnetic resonance imaging (rs-fMRI) data of healthy adult individuals (N = 85; 19-85 years). We further examined effects of age on FC of the identified CBF clusters and assessed the reproducibility of cluster-specific FC profiles in independent data from healthy older individuals (N = 25; 65-89 years). Results showed that the human CBF is functionally organized into distinct anterior-medial and posterior-lateral subdivisions that largely follow anatomically defined boundaries of the medial septum/diagonal band and nucleus basalis Meynert. The anterior-medial CBF subdivision was characterized by connectivity with the hippocampus and interconnected nodes of an extended medial cortical memory network, whereas the posterior-lateral subdivision was specifically connected to anterior insula and dorsal anterior cingulate components of a salience/attention network. FC of both CBF subdivisions declined with increasing age, but the overall topography of subregion-specific FC profiles was reproduced in independent rs-fMRI data of healthy older individuals acquired in a typical clinical setting. Rs-fMRI-based assessments of subregion-specific CBF function may complement established volumetric approaches for the in vivo study of CBF involvement in neuropsychiatric disorders.
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Affiliation(s)
- Hans‐Christian J. Fritz
- Clinical Dementia Research SectionGerman Center for Neurodegenerative Diseases (DZNE)RostockGermany
- Department of Psychosomatic and Psychotherapeutic MedicineRostock University Medical CenterRostockGermany
| | - Nicola Ray
- Department of PsychologyManchester Metropolitan UniversityManchesterUK
| | - Martin Dyrba
- Clinical Dementia Research SectionGerman Center for Neurodegenerative Diseases (DZNE)RostockGermany
| | - Christian Sorg
- Departments of Neuroradiology and Psychiatry, TUM‐Neuroimaging Center of Klinikum rechts der IsarTechnische Universität München TUMMunichGermany
| | - Stefan Teipel
- Clinical Dementia Research SectionGerman Center for Neurodegenerative Diseases (DZNE)RostockGermany
- Department of Psychosomatic and Psychotherapeutic MedicineRostock University Medical CenterRostockGermany
| | - Michel J. Grothe
- Clinical Dementia Research SectionGerman Center for Neurodegenerative Diseases (DZNE)RostockGermany
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Giorgi FS, Ryskalin L, Ruffoli R, Biagioni F, Limanaqi F, Ferrucci M, Busceti CL, Bonuccelli U, Fornai F. The Neuroanatomy of the Reticular Nucleus Locus Coeruleus in Alzheimer's Disease. Front Neuroanat 2017; 11:80. [PMID: 28974926 PMCID: PMC5610679 DOI: 10.3389/fnana.2017.00080] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 09/05/2017] [Indexed: 11/13/2022] Open
Abstract
Alzheimer’s Disease (AD) features the accumulation of β-amyloid and Tau aggregates, which deposit as extracellular plaques and intracellular neurofibrillary tangles (NFTs), respectively. Neuronal Tau aggregates may appear early in life, in the absence of clinical symptoms. This occurs in the brainstem reticular formation and mostly within Locus Coeruleus (LC), which is consistently affected during AD. LC is the main source of forebrain norepinephrine (NE) and it modulates a variety of functions including sleep-waking cycle, alertness, synaptic plasticity, and memory. The iso-dendritic nature of LC neurons allows their axons to spread NE throughout the whole forebrain. Likewise, a prion-like hypothesis suggests that Tau aggregates may travel along LC axons to reach out cortical neurons. Despite this timing is compatible with cross-sectional studies, there is no actual evidence for a causal relationship between these events. In the present mini-review, we dedicate special emphasis to those various mechanisms that may link degeneration of LC neurons to the onset of AD pathology. This includes the hypothesis that a damage to LC neurons contributes to the onset of dementia due to a loss of neuroprotective effects or, even the chance that, LC degenerates independently from cortical pathology. At the same time, since LC neurons are lost in a variety of neuropsychiatric disorders we considered which molecular mechanism may render these brainstem neurons so vulnerable.
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Affiliation(s)
- Filippo S Giorgi
- Section of Neurology, Pisa University Hospital, Department of Clinical and Experimental Medicine, University of PisaPisa, Italy
| | - Larisa Ryskalin
- Department of Translational Research and New Technologies in Medicine and Surgery, University of PisaPisa, Italy
| | - Riccardo Ruffoli
- Department of Translational Research and New Technologies in Medicine and Surgery, University of PisaPisa, Italy
| | | | - Fiona Limanaqi
- Department of Translational Research and New Technologies in Medicine and Surgery, University of PisaPisa, Italy
| | - Michela Ferrucci
- Department of Translational Research and New Technologies in Medicine and Surgery, University of PisaPisa, Italy
| | | | - Ubaldo Bonuccelli
- Section of Neurology, Pisa University Hospital, Department of Clinical and Experimental Medicine, University of PisaPisa, Italy
| | - Francesco Fornai
- Department of Translational Research and New Technologies in Medicine and Surgery, University of PisaPisa, Italy.,I.R.C.C.S. I.N.M. NeuromedPozzilli, Italy
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Al Abed AS, Sellami A, Brayda-Bruno L, Lamothe V, Noguès X, Potier M, Bennetau-Pelissero C, Marighetto A. Estradiol enhances retention but not organization of hippocampus-dependent memory in intact male mice. Psychoneuroendocrinology 2016; 69:77-89. [PMID: 27038677 DOI: 10.1016/j.psyneuen.2016.03.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 03/18/2016] [Accepted: 03/19/2016] [Indexed: 10/22/2022]
Abstract
Because estrogens have mostly been studied in gonadectomized females, effects of chronic exposure to environmental estrogens in the general population are underestimated. Estrogens can enhance hippocampus-dependent memory through the modulation of information storage. However, declarative memory, the hippocampus-dependent memory of facts and events, demands more than abilities to retain information. Specifically, memory of repetitive events of everyday life such as "where I parked" requires abilities to organize/update memories to prevent proactive interference from similar memories of previous "parking events". Whether such organizational processes are estrogen-sensitive is unknown. We here studied, in intact young and aged adult mice, drinking-water (1μM) estradiol effects on both retention and organizational components of hippocampus-dependent memory, using a radial-maze task of everyday-like memory. Demand on retention vs organization was manipulated by varying the time-interval separating repetitions of similar events. Estradiol increased performance in young and aged mice under minimized organizational demand, but failed to improve the age-associated memory impairment and diminished performance in young mice under high organizational demand. In fact, estradiol prolonged mnemonic retention of successive events without improving organization abilities, hence resulted in more proactive interference from irrelevant memories. c-Fos imaging of testing-induced brain activations showed that the deterioration of young memory was associated with dentate gyrus dysconnectivity, reminiscent of that seen in aged mice. Our findings support the view that estradiol is promnesic but also reveal that such property can paradoxically impair memory. These findings have important outcomes regarding health issues relative to the impact of environmental estrogens in the general population.
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Affiliation(s)
- Alice Shaam Al Abed
- Neurocentre Magendie, INSERM U1215, F-33000 Bordeaux, France; Université de Bordeaux, F-33000 Bordeaux, France
| | - Azza Sellami
- Neurocentre Magendie, INSERM U1215, F-33000 Bordeaux, France; Université de Bordeaux, F-33000 Bordeaux, France
| | - Laurent Brayda-Bruno
- Neurocentre Magendie, INSERM U1215, F-33000 Bordeaux, France; Université de Bordeaux, F-33000 Bordeaux, France
| | - Valérie Lamothe
- Neurocentre Magendie, INSERM U1215, F-33000 Bordeaux, France; Université de Bordeaux, F-33000 Bordeaux, France
| | - Xavier Noguès
- Neurocentre Magendie, INSERM U1215, F-33000 Bordeaux, France; Université de Bordeaux, F-33000 Bordeaux, France
| | - Mylène Potier
- Neurocentre Magendie, INSERM U1215, F-33000 Bordeaux, France; Université de Bordeaux, F-33000 Bordeaux, France
| | | | - Aline Marighetto
- Neurocentre Magendie, INSERM U1215, F-33000 Bordeaux, France; Université de Bordeaux, F-33000 Bordeaux, France.
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Paul S, Jeon WK, Bizon JL, Han JS. Interaction of basal forebrain cholinergic neurons with the glucocorticoid system in stress regulation and cognitive impairment. Front Aging Neurosci 2015; 7:43. [PMID: 25883567 PMCID: PMC4382969 DOI: 10.3389/fnagi.2015.00043] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 03/12/2015] [Indexed: 11/28/2022] Open
Abstract
A substantial number of studies on basal forebrain (BF) cholinergic neurons (BFCN) have provided compelling evidence for their role in the etiology of stress, cognitive aging, Alzheimer’s disease (AD), and other neurodegenerative diseases. BFCN project to a broad range of cortical sites and limbic structures, including the hippocampus, and are involved in stress and cognition. In particular, the hippocampus, the primary target tissue of the glucocorticoid stress hormones, is associated with cognitive function in tandem with hypothalamic-pituitary-adrenal (HPA) axis modulation. The present review summarizes glucocorticoid and HPA axis research to date in an effort to establish the manner in which stress affects the release of acetylcholine (ACh), glucocorticoids, and their receptor in the context of cognitive processes. We attempt to provide the molecular interactive link between the glucocorticoids and cholinergic system that contributes to BFCN degeneration in stress-induced acceleration of cognitive decline in aging and AD. We also discuss the importance of animal models in facilitating such studies for pharmacological use, to which could help decipher disease states and propose leads for pharmacological intervention.
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Affiliation(s)
- Saswati Paul
- Department of Biological Sciences, Konkuk University Seoul, South Korea
| | - Won Kyung Jeon
- Herbal Medicine Research Division, Korea Institute of Oriental Medicine Daejeon, South Korea
| | - Jennifer L Bizon
- Department of Neuroscience, College of Medicine, Evelyn F. and William L. McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Jung-Soo Han
- Department of Biological Sciences, Konkuk University Seoul, South Korea
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Fassini A, Antero LS, Corrêa FMA, Joca SR, Resstel LBM. The prelimbic cortex muscarinic M₃ receptor-nitric oxide-guanylyl cyclase pathway modulates cardiovascular responses in rats. J Neurosci Res 2015; 93:830-8. [PMID: 25594849 DOI: 10.1002/jnr.23537] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 10/01/2014] [Accepted: 11/10/2014] [Indexed: 11/06/2022]
Abstract
The prelimbic cortex (PL), a limbic structure, sends projections to areas involved in the control of cardiovascular responses. Stimulation of the PL with acetylcholine (ACh) evokes depressor and tachycardiac responses mediated by local PL muscarinic receptors. Early studies demonstrated that stimulation of muscarinic receptors induced nitric oxide (NO) synthesis and cyclic guanosine cyclic monophosphate (cGMP) formation. Hence, this study investigates which PL muscarinic receptor subtype is involved in the cardiovascular response induced by ACh and tests the hypothesis that cardiovascular responses caused by muscarinic receptor stimulation in the PL are mediated by local NO and cGMP formation. PL pretreatment with J104129 (an M3 receptor antagonist) blocked the depressor and tachycardiac response evoked by injection of ACh into the PL. Pretreatment with either pirenzepine (an M1 receptor antagonist) or AF-DX 116 (an M2 and M4 receptor antagonist) did not affect cardiovascular responses evoked by ACh. Moreover, similarly to the antagonism of PL M3 receptors, pretreatment with N(ω)-propyl-L-arginine (an inhibitor of neuronal NO synthase), carboxy-PTIO(S)-3-carboxy-4-hydroxyphenylglicine (an NO scavenger), or 1H-[1,2,4]oxadiazolol-[4,3-a]quinoxalin-1-one (a guanylate cyclase inhibitor) blocked both the depressor and the tachycardiac response evoked by ACh. The current results demonstrate that cardiovascular responses evoked by microinjection of ACh into the PL are mediated by local activation of the M3 receptor-NO-guanylate cyclase pathway.
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Affiliation(s)
- Aline Fassini
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
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Naseh M, Vatanparast J. Enhanced expression of hypothalamic nitric oxide synthase in rats developmentally exposed to organophosphates. Brain Res 2014; 1579:10-9. [PMID: 25050544 DOI: 10.1016/j.brainres.2014.07.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Revised: 05/24/2014] [Accepted: 07/13/2014] [Indexed: 11/29/2022]
Abstract
Nitric oxide synthase (NOS) is highly expressed in the hypothalamus, and nitric oxide (NO) specifically contributes to the regulation of neuronal activity within distinct hypothalamic regions. We studied the long-lasting effects of developmental exposure to low doses of organophosphate chlorpyrifos (CPF) and diazinon (DZN) on the expression of NOS in the hypothalamic subnuclei that subserve neuroendocrine, autonomic and cognitive functions. A daily dose of 1 mg/kg of either CPF or DZN was administered to developing rats during gestational days 15-18 or postnatal days (PND) 1-4. Brain sections from PND 60 rats were processed using NADPH-diaphorase (NADPH-d) and neuronal NOS (nNOS) immunohistochemistry. The number of labeled neurons and the optical density (OD) were assessed in the supraoptic (SON), paraventricular (PVN), medial septum, vertical limb, and horizontal limb of the diagonal band. Developmental exposure to organophosphates increased the number of labeled neurons and OD in different subnuclei in the hypothalamus without gender selectivity. The effect on OD was more pronounced and was significant for more cases. Prenatal exposure to CPF and DZN significantly increased the OD in all regions studied with the exception of PVN. Neonatal exposure to DZN also consistently increased OD in all studied subnuclei. For rats that treated with CPF during early postnatal period, this effect was statistically significant only for the SON and PVN. These findings suggest that overexpression of NOS in the hypothalamus may contribute to the mechanisms inducing or compensating for endocrine, autonomic and cognitive abnormalities after developmental exposure to organophosphates.
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Affiliation(s)
- Maryam Naseh
- Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran; Department of Physiology, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Jafar Vatanparast
- Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran.
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Baudonnat M, Huber A, David V, Walton ME. Heads for learning, tails for memory: reward, reinforcement and a role of dopamine in determining behavioral relevance across multiple timescales. Front Neurosci 2013; 7:175. [PMID: 24130514 PMCID: PMC3795326 DOI: 10.3389/fnins.2013.00175] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Accepted: 09/09/2013] [Indexed: 11/13/2022] Open
Abstract
Dopamine has long been tightly associated with aspects of reinforcement learning and motivation in simple situations where there are a limited number of stimuli to guide behavior and constrained range of outcomes. In naturalistic situations, however, there are many potential cues and foraging strategies that could be adopted, and it is critical that animals determine what might be behaviorally relevant in such complex environments. This requires not only detecting discrepancies with what they have recently experienced, but also identifying similarities with past experiences stored in memory. Here, we review what role dopamine might play in determining how and when to learn about the world, and how to develop choice policies appropriate to the situation faced. We discuss evidence that dopamine is shaped by motivation and memory and in turn shapes reward-based memory formation. In particular, we suggest that hippocampal-striatal-dopamine networks may interact to determine how surprising the world is and to either inhibit or promote actions at time of behavioral uncertainty.
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Affiliation(s)
- Mathieu Baudonnat
- Department of Experimental Psychology, University of Oxford Oxford, UK
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