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Bai T, Zhan L, Zhang N, Lin F, Saur D, Xu C. Learning-prolonged maintenance of stimulus information in CA1 and subiculum during trace fear conditioning. Cell Rep 2023; 42:112853. [PMID: 37481720 DOI: 10.1016/j.celrep.2023.112853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 04/12/2023] [Accepted: 07/08/2023] [Indexed: 07/25/2023] Open
Abstract
Temporal associative learning binds discontiguous conditional stimuli (CSs) and unconditional stimuli (USs), possibly by maintaining CS information in the hippocampus after its offset. Yet, how learning regulates such maintenance of CS information in hippocampal circuits remains largely unclear. Using the auditory trace fear conditioning (TFC) paradigm, we identify a projection from the CA1 to the subiculum critical for TFC. Deep-brain calcium imaging shows that the peak of trace activity in the CA1 and subiculum is extended toward the US and that the CS representation during the trace period is enhanced during learning. Interestingly, such plasticity is consolidated only in the CA1, not the subiculum, after training. Moreover, CA1 neurons, but not subiculum neurons, increasingly become active during CS-and-trace and shock periods, respectively, and correlate with CS-evoked fear retrieval afterward. These results indicate that learning dynamically enhances stimulus information maintenance in the CA1-subiculum circuit during learning while storing CS and US memories primarily in the CA1 area.
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Affiliation(s)
- Tao Bai
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Lijie Zhan
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Na Zhang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Feikai Lin
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Dieter Saur
- Department of Internal Medicine 2, Technische Universität München, Ismaningerstrasse 22, 81675 Munich, Germany
| | - Chun Xu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China; University of the Chinese Academy of Sciences, Beijing 100049, China; Shanghai Center for Brain Science and Brain-Inspired Technology, Shanghai 201210, China.
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2
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N-Methyl-D-Aspartate (NMDA) Receptors in the Prelimbic Cortex Are Required for Short- and Long-Term Memory Formation in Trace Fear Conditioning. Life (Basel) 2022; 12:life12050672. [PMID: 35629340 PMCID: PMC9147616 DOI: 10.3390/life12050672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 11/29/2022] Open
Abstract
Accumulating evidence suggests that the medial prefrontal cortex (mPFC) has been implicated in the acquisition of fear memory during trace fear conditioning in which a conditional stimulus (CS) is paired with an aversive unconditional stimulus (UCS) separated by a temporal gap (trace interval, TI). However, little is known about the role of the prefrontal cortex for short- and long-term trace fear memory formation. Thus, we investigated how the prelimbic (PL) subregion within mPFC in rats contributes to short- and long-term trace fear memory formation using electrolytic lesions and d,l,-2-amino-5-phosphonovaleric acid (APV), an N-methyl-D-aspartate receptor (NMDAR) antagonist infusions into PL. In experiment 1, pre-conditioning lesions of PL impaired freezing to the CS as well as TI during the acquisition and retrieval sessions, indicating that PL is critically involved in trace fear memory formation. In experiment 2, temporary blockade of NMDA receptors in PL impaired the acquisition, but not the expression of short- and long-term trace fear memory. In addition, the inactivation of NMDAR in PL had little effect on locomotor activity, pre-pulse inhibition (PPI), or shock sensitivity. Taken together, these results suggest that NMDA receptor-mediated neurotransmission in PL is required for the acquisition of trace fear memory.
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3
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Zorzo C, Arias JL, Méndez M. Functional neuroanatomy of allocentric remote spatial memory in rodents. Neurosci Biobehav Rev 2022; 136:104609. [PMID: 35278596 DOI: 10.1016/j.neubiorev.2022.104609] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/03/2022] [Accepted: 03/06/2022] [Indexed: 12/12/2022]
Abstract
Successful spatial cognition involves learning, consolidation, storage, and later retrieval of a spatial memory trace. The functional contributions of specific brain areas and their interactions during retrieval of past spatial events are unclear. This systematic review collects studies about allocentric remote spatial retrieval assessed at least two weeks post-acquisition in rodents. Results including non-invasive interventions, brain lesion and inactivation experiments, pharmacological treatments, chemical agent administration, and genetic manipulations revealed that there is a normal forgetting when time-periods are close to or exceed one month. Moreover, changes in the morphology and functionality of neocortical areas, hippocampus, and other subcortical structures, such as the thalamus, have been extensively observed as a result of spatial memory retrieval. In conclusion, apart from an increasingly neocortical recruitment in remote spatial retrieval, the hippocampus seems to participate in the retrieval of fine spatial details. These results help to better understand the timing of memory maintenance and normal forgetting, outlining the underlying brain areas implicated.
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Affiliation(s)
- Candela Zorzo
- Department of Psychology, University of Oviedo, Faculty of Psychology, Plaza Feijoo s/n, 33003 Oviedo, Asturias, Spain; Neuroscience Institute of Principado de Asturias (INEUROPA).
| | - Jorge L Arias
- Department of Psychology, University of Oviedo, Faculty of Psychology, Plaza Feijoo s/n, 33003 Oviedo, Asturias, Spain; Neuroscience Institute of Principado de Asturias (INEUROPA).
| | - Marta Méndez
- Department of Psychology, University of Oviedo, Faculty of Psychology, Plaza Feijoo s/n, 33003 Oviedo, Asturias, Spain; Neuroscience Institute of Principado de Asturias (INEUROPA).
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4
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Herbst MR, Twining RC, Gilmartin MR. Ventral hippocampal shock encoding modulates the expression of trace cued fear. Neurobiol Learn Mem 2022; 190:107610. [PMID: 35302040 DOI: 10.1016/j.nlm.2022.107610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 02/02/2022] [Accepted: 03/03/2022] [Indexed: 12/24/2022]
Abstract
The hippocampus is crucial for associative fear learning when the anticipation of threat requires temporal or contextual binding of predictive stimuli as in trace and contextual fear conditioning. Compared with the dorsal hippocampus, far less is known about the contribution of the ventral hippocampus to fear learning. The ventral hippocampus, which is highly interconnected with defensive and emotional networks, has a prominent role in both innate and learned affective behaviors including anxiety, fear, and reward. Lesions or temporary inactivation of the ventral hippocampus impair both cued and contextual fear learning, but whether the ventral hippocampal role in learning is driven by affective processing, associative encoding, or both is not clear. Here, we used trace fear conditioning in mixed sex cohorts to assess the contribution of shock-encoding to the acquisition of cued and contextual fear memories. Trace conditioning requires subjects to associate an auditory conditional stimulus (CS) with a shock unconditional stimulus (UCS) that are separated in time by a 20-s trace interval. We first recorded neuronal activity in the ventral hippocampus during trace fear conditioning and found that ventral CA1 predominantly encoded the shock reinforcer. Potentiated firing to the CS was evident at testing, but no encoding of the trace interval was observed. We then tested the necessity of shock encoding for conditional fear acquisition by optogenetically silencing ventral hippocampal activity during the UCS on each trial of training. Contrary to our predictions, preventing hippocampal shock-evoked firing did not impair associative fear. Instead, it led to a more prolonged expression of CS freezing across test trials, an effect observed in males, but not females. Contextual fear learning was largely intact, although a subset of animals in each sex were differentially affected by shock-silencing. Taken together, the results show that shock encoding in the ventral hippocampus modulates the expression of learned fear in a sex-specific manner.
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Affiliation(s)
- Matthew R Herbst
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53233, USA
| | - Robert C Twining
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53233, USA
| | - Marieke R Gilmartin
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI 53233, USA.
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5
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Comeras LB, Hörmer N, Mohan Bethuraj P, Tasan RO. NPY Released From GABA Neurons of the Dentate Gyrus Specially Reduces Contextual Fear Without Affecting Cued or Trace Fear. Front Synaptic Neurosci 2021; 13:635726. [PMID: 34122036 PMCID: PMC8187774 DOI: 10.3389/fnsyn.2021.635726] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 04/20/2021] [Indexed: 11/15/2022] Open
Abstract
Disproportionate, maladapted, and generalized fear are essential hallmarks of posttraumatic stress disorder (PTSD), which develops upon severe trauma in a subset of exposed individuals. Among the brain areas that are processing fear memories, the hippocampal formation exerts a central role linking emotional-affective with cognitive aspects. In the hippocampus, neuronal excitability is constrained by multiple GABAergic interneurons with highly specialized functions and an extensive repertoire of co-released neuromodulators. Neuropeptide Y (NPY) is one of these co-transmitters that significantly affects hippocampal signaling, with ample evidence supporting its fundamental role in emotional, cognitive, and metabolic circuitries. Here we investigated the role of NPY in relation to GABA, both released from the same interneurons of the dorsal dentate gyrus (DG), in different aspects of fear conditioning. We demonstrated that activation of dentate GABA neurons specifically during fear recall reduced cue-related as well as trace-related freezing behavior, whereas inhibition of the same neurons had no significant effects. Interestingly, concomitant overexpression of NPY in these neurons did not further modify fear recall, neither under baseline conditions nor upon chemogenetic stimulation. However, potentially increased co-release of NPY substantially reduced contextual fear, promoted extinction learning, and long-term suppression of fear in a foreground context–conditioning paradigm. Importantly, NPY in the dorsal DG was not only expressed in somatostatin neurons, but also in parvalbumin-positive basket cells and axoaxonic cells, indicating intense feedback and feedforward modulation of hippocampal signaling and precise curtailing of neuronal engrams. Thus, these findings suggest that co-release of NPY from specific interneuron populations of the dorsal DG modifies dedicated aspects of hippocampal processing by sharpening the activation of neural engrams and the consecutive fear response. Since inappropriate and generalized fear is the major impediment in the treatment of PTSD patients, the dentate NPY system may be a suitable access point to ameliorate PTSD symptoms and improve the inherent disease course.
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Affiliation(s)
- Lucas B Comeras
- Department of Pharmacology, Medical University Innsbruck, Innsbruck, Austria
| | - Noa Hörmer
- Department of Pharmacology, Medical University Innsbruck, Innsbruck, Austria
| | | | - Ramon O Tasan
- Department of Pharmacology, Medical University Innsbruck, Innsbruck, Austria
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Ehlers VL, Smies CW, Moyer JR. Apoaequorin differentially modulates fear memory in adult and aged rats. Brain Behav 2020; 10:e01832. [PMID: 32945630 PMCID: PMC7667302 DOI: 10.1002/brb3.1832] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 08/11/2020] [Accepted: 08/18/2020] [Indexed: 01/06/2023] Open
Abstract
INTRODUCTION Cognitive deficits during aging are pervasive across species and learning paradigms. One of the major mechanisms thought to play a role in age-related memory decline is dysregulated calcium (Ca2+ ) homeostasis. Aging is associated with impaired function of several calcium-regulatory mechanisms, including calcium-binding proteins that normally support intracellular Ca2+ regulation. This age-related calcium-binding protein dysfunction and changes in expression lead to disrupted maintenance of intracellular Ca2+ , thus contributing to memory decline. Other work has found that age-related cognitive deficits can be mitigated by either blocking Ca2+ entry into the cytosol or preventing its release from intracellular Ca2+ stores. However, the effect of calcium-binding protein administration on cognitive function during aging is not well-understood. Our laboratory has previously shown that the calcium-binding protein apoaequorin (AQ) is neuroprotective during oxygen-glucose deprivation, a model of in vitro ischemia characterized by calcium-induced excitotoxicity. The current experiments assessed the effect of direct dorsal hippocampal AQ infusion on trace and context fear memory in adult and aged rats. METHODS Adult (3-6 months) and aged (22-26 months) male F344 rats were randomly assigned to different experimental infusion groups before undergoing trace fear conditioning and testing. In experiment 1, rats received bilateral dorsal hippocampal infusions of either vehicle or AQ (4% w/v) 24 hr before trace fear conditioning. In experiment 2, rats received bilateral dorsal hippocampal infusions of either vehicle or 4% AQ 1 hr before trace fear conditioning and 1 hr before testing. RESULTS Aged rats displayed impaired trace and context fear memory. While a single AQ infusion 24 hr before trace fear conditioning was insufficient to rescue age-related trace fear memory deficits, AQ infusion 1 hr before both conditioning and testing abolished age-related context fear memory deficits. CONCLUSIONS These results suggest that intrahippocampal infusion of AQ may reverse aging-related deficits in hippocampus-dependent context fear memory.
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Affiliation(s)
- Vanessa L Ehlers
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Chad W Smies
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - James R Moyer
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA.,Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
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7
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Zorzo C, Arias JL, Méndez M. Retrieval of allocentric spatial memories is preserved up to thirty days and does not require higher brain metabolic demands. Neurobiol Learn Mem 2020; 175:107312. [DOI: 10.1016/j.nlm.2020.107312] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 07/17/2020] [Accepted: 08/30/2020] [Indexed: 01/13/2023]
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8
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Ferreira JS, de Mello Bastos JM, Leite Junior JB, Samuels RI, Carey RJ, Carrera MP. Morphine administered post-trial induces potent morphine conditioned effects if the context is novel but not if the context is familiar. Pharmacol Biochem Behav 2020; 196:172978. [PMID: 32593788 DOI: 10.1016/j.pbb.2020.172978] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 06/14/2020] [Accepted: 06/23/2020] [Indexed: 11/18/2022]
Abstract
Morphine administered shortly after exposure to a novel environment induces potent locomotor stimulant conditioning. Environmental novelty is important as pre-exposure (PE) to a stimulus can attenuate the capacity to acquire conditioned stimulus (CS). Here, the importance of environmental novelty for the efficacy of an open-field to become a CS for elicitation of a morphine conditioned response was assessed by comparing the effects of morphine administered post-trial following a 5 min exposure to a novel environment versus a PE environment. Four groups of rats (2 vehicle and 2 morphine groups) were used. Two groups received ten daily 5 min non-drug PEs to an open-field arena and the other two groups were not pre-exposed to the environment. Subsequently, all groups received post-trial injections of either vehicle or morphine immediately after each of five daily 5 min sessions in the open-field. Importantly, on the first day of testing prior to the first post-test morphine administration, the locomotor activity of the novel and PE groups was not different. Over the 5 post-trial morphine treatments, the activity of the PE morphine group, the PE vehicle and the novel environment vehicle groups did not change and were equivalent. In contrast, in the novel environment morphine group, a conditioned hyper-activity response increased with repeated post-trial morphine treatments. For the morphine group it is suggested that the novel environment initiated a post-trial stimulus trace that occurred in temporal contiguity with the post-trial drug response and enabled the trace to become a CS for the morphine unconditioned response. In contrast, PE induced a latent inhibition effect in the PE morphine group, thus the post-trial CS trace was insufficient to become associated to the morphine response and no conditioning occurred. In addition to conventional drug induced Pavlovian delay conditioning, the findings are suggestive of drug induced Pavlovian trace conditioning.
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Affiliation(s)
- Jaise Silva Ferreira
- Behavioral Pharmacology Group, Laboratory of Animal Morphology and Pathology, State University of North Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, Campos dos Goytacazes 28013-602, RJ, Brazil
| | - João Marcos de Mello Bastos
- Behavioral Pharmacology Group, Laboratory of Animal Morphology and Pathology, State University of North Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, Campos dos Goytacazes 28013-602, RJ, Brazil
| | - Joaquim Barbosa Leite Junior
- Behavioral Pharmacology Group, Laboratory of Animal Morphology and Pathology, State University of North Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, Campos dos Goytacazes 28013-602, RJ, Brazil
| | - Richard Ian Samuels
- Department of Entomology and Plant Pathology, State University of North Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil
| | - Robert J Carey
- Department of Psychiatry, SUNY Upstate Medical University, 800 Irving Avenue, Syracuse, NY 13210, USA
| | - Marinete Pinheiro Carrera
- Behavioral Pharmacology Group, Laboratory of Animal Morphology and Pathology, State University of North Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, Campos dos Goytacazes 28013-602, RJ, Brazil.
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9
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Lissemore JI, Nagano-Saito A, Smart K, Gravel P, Leyton M, Benkelfat C. Dopaminergic Plasticity in the Bilateral Hippocampus Following Threat Reversal in Humans. Sci Rep 2020; 10:7627. [PMID: 32376865 PMCID: PMC7203150 DOI: 10.1038/s41598-020-63977-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 04/06/2020] [Indexed: 11/24/2022] Open
Abstract
When a cue no longer predicts a threat, a diminished ability to extinguish or reverse this association is thought to increase risk for stress-related disorders. Despite the clear clinical relevance, the mediating neurochemical mechanisms of threat reversal have received relatively little study. One neurotransmitter implicated in rodent research of changing associations with threat is dopamine. To study whether dopamine is involved in threat reversal in humans, we used high-resolution positron emission tomography (PET) coupled with 18F-fallypride. Twelve healthy volunteers (6 F/6 M) underwent three PET scans: (i) at baseline, (ii) following threat conditioning (the response to a cue associated with electric wrist shock), and (iii) following threat reversal (the response to the same cue now associated with safety). We observed moderate evidence of reduced dopamine D2/3 receptor availability, consistent with greater dopamine release, in the bilateral anterior hippocampus following threat reversal, in response to a safety cue that was previously associated with threat, as compared to both baseline and during exposure to the same cue prior to threat reversal. These findings offer the first preliminary evidence that the response to a previously threatening cue that has since become associated with safety involves dopaminergic neurotransmission within the hippocampus in healthy humans.
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Affiliation(s)
- Jennifer I Lissemore
- Department of Psychiatry, McGill University, 1033 Pine Avenue West, Montreal, H3A 1A1, Quebec, Canada.
| | - Atsuko Nagano-Saito
- Department of Psychiatry, McGill University, 1033 Pine Avenue West, Montreal, H3A 1A1, Quebec, Canada
| | - Kelly Smart
- Department of Psychiatry, McGill University, 1033 Pine Avenue West, Montreal, H3A 1A1, Quebec, Canada
| | - Paul Gravel
- Department of Psychiatry, McGill University, 1033 Pine Avenue West, Montreal, H3A 1A1, Quebec, Canada
- Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, 3801 University St., Montreal, H3A 2B4, Quebec, Canada
| | - Marco Leyton
- Department of Psychiatry, McGill University, 1033 Pine Avenue West, Montreal, H3A 1A1, Quebec, Canada
- Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, 3801 University St., Montreal, H3A 2B4, Quebec, Canada
| | - Chawki Benkelfat
- Department of Psychiatry, McGill University, 1033 Pine Avenue West, Montreal, H3A 1A1, Quebec, Canada
- Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, 3801 University St., Montreal, H3A 2B4, Quebec, Canada
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10
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Yousuf H, Ehlers VL, Sehgal M, Song C, Moyer JR. Modulation of intrinsic excitability as a function of learning within the fear conditioning circuit. Neurobiol Learn Mem 2019; 167:107132. [PMID: 31821881 DOI: 10.1016/j.nlm.2019.107132] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 11/27/2019] [Indexed: 11/28/2022]
Abstract
Experience-dependent neuronal plasticity is a fundamental substrate of learning and memory. Intrinsic excitability is a form of neuronal plasticity that can be altered by learning and indicates the pattern of neuronal responding to external stimuli (e.g. a learning or synaptic event). Associative fear conditioning is one form of learning that alters intrinsic excitability, reflecting an experience-dependent change in neuronal function. After fear conditioning, intrinsic excitability changes are evident in brain regions that are a critical part of the fear circuit, including the amygdala, hippocampus, retrosplenial cortex, and prefrontal cortex. Some of these changes are transient and/or reversed by extinction as well as learning-specific (i.e. they are not observed in neurons from control animals). This review will explore how intrinsic neuronal excitability changes within brain structures that are critical for fear learning, and it will also discuss evidence promoting intrinsic excitability as a vital mechanism of associative fear memories. This work has raised interesting questions regarding the role of fear learning in changes of intrinsic excitability within specific subpopulations of neurons, including those that express immediate early genes and thus demonstrate experience-dependent activity, as well as in neurons classified as having a specific firing type (e.g. burst-spiking vs. regular-spiking). These findings have interesting implications for how intrinsic excitability can serve as a neural substrate of learning and memory, and suggest that intrinsic plasticity within specific subpopulations of neurons may promote consolidation of the memory trace in a flexible and efficient manner.
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Affiliation(s)
- Hanna Yousuf
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
| | - Vanessa L Ehlers
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
| | - Megha Sehgal
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
| | - Chenghui Song
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
| | - James R Moyer
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA; Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA.
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11
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Wilmot JH, Puhger K, Wiltgen BJ. Acute Disruption of the Dorsal Hippocampus Impairs the Encoding and Retrieval of Trace Fear Memories. Front Behav Neurosci 2019; 13:116. [PMID: 31191269 PMCID: PMC6548811 DOI: 10.3389/fnbeh.2019.00116] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 05/16/2019] [Indexed: 11/13/2022] Open
Abstract
A major function of the hippocampus is to link discontiguous events in memory. This process can be studied in animals using Pavlovian trace conditioning, a procedure where the conditional stimulus (CS) and unconditional stimulus (US) are separated in time. While the majority of studies have found that trace conditioning requires the dorsal segment of the hippocampus, others have not. This variability could be due to the use of lesion and pharmacological techniques, which lack cell specificity and temporal precision. More recent studies using optogenetic tools find that trace fear acquisition is disrupted by decreases in dorsal CA1 (dCA1) activity while increases lead to learning enhancements. However, comparing these results is difficult given that some studies manipulated the activity of CA1 pyramidal neurons directly and others did so indirectly (e.g., via stimulation of entorhinal cortex inputs). The goal of the current experiments, therefore, was to compare the effects of direct CA1 excitation and inhibition on the encoding and expression of trace fear memories. Our data indicates that stimulation of ArchT in dCA1 pyramidal neurons reduces activity and impairs both the acquisition and retrieval of trace fear. Unlike previous work, direct stimulation of CA1 with ChR2 increases activity and produces deficits in trace fear learning and expression. We hypothesize that this is due to the artificial nature of optogenetic stimulation, which could disrupt processing throughout the hippocampus and in downstream structures.
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Affiliation(s)
- Jacob H Wilmot
- Department of Psychology, University of California, Davis, Davis, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
| | - Kyle Puhger
- Department of Psychology, University of California, Davis, Davis, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
| | - Brian J Wiltgen
- Department of Psychology, University of California, Davis, Davis, CA, United States.,Center for Neuroscience, University of California, Davis, Davis, CA, United States
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12
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Zhang Y, Ouyang K, Lipina TV, Wang H, Zhou Q. Conditioned stimulus presentations alter anxiety level in fear-conditioned mice. Mol Brain 2019; 12:28. [PMID: 30925893 PMCID: PMC6441152 DOI: 10.1186/s13041-019-0445-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 03/13/2019] [Indexed: 11/26/2022] Open
Abstract
It is generally believed that fear is rapidly triggered by a distinct cue while anxiety onset is less precise and not associated with a distinct cue. Although it has been claimed that both processes can be measured with certain independence of each other, it is unclear how exactly they differ. In this study, we measured anxiety in mice that received discriminative fear conditioning using behavioral, heart rate and calcium (Ca2+) responses in the ventral hippocampal CA1 (vCA1) neurons. We found that the occurrence of fear significantly interfered with anxiety measurements under various conditions. Diazepam reduced basal anxiety level but had no effect during the presentation of conditioned stimulus (CS). Injection of an inhibitory peptide of PKMzeta (ZIP) into the basolateral amygdala almost entirely abolished CS-triggered fear expression and reduced anxiety to basal level. Heart rate measures suggested a small reduction in anxiety during CS-. Calcium responses in the lateral hypothalamus-projecting vCA1 neurons showed a steady decay during CS suggesting a reduced anxiety. Thus, under our experimental conditions, CS presentations likely reduce anxiety level in the fear-conditioned mice.
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Affiliation(s)
- Yujie Zhang
- State key laboratory of chemical oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Kunfu Ouyang
- State key laboratory of chemical oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Tatiana V Lipina
- Federal State Budgetary Scientific Institution, Scientific Research Institute of Physiology and Basic Medicine, Novosibirsk, Russia.,University of Toronto, Department of Pharmacology & Toxicology, Toronto, Ontario, Canada
| | - Hong Wang
- State key laboratory of chemical oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Qiang Zhou
- State key laboratory of chemical oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China.
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13
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Hippocampal NPY Y2 receptors modulate memory depending on emotional valence and time. Neuropharmacology 2018; 143:20-28. [DOI: 10.1016/j.neuropharm.2018.09.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 08/29/2018] [Accepted: 09/11/2018] [Indexed: 12/13/2022]
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14
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Connor DA, Gould TJ. The role of working memory and declarative memory in trace conditioning. Neurobiol Learn Mem 2016; 134 Pt B:193-209. [PMID: 27422017 PMCID: PMC5755400 DOI: 10.1016/j.nlm.2016.07.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 07/07/2016] [Accepted: 07/11/2016] [Indexed: 01/18/2023]
Abstract
Translational assays of cognition that are similarly implemented in both lower and higher-order species, such as rodents and primates, provide a means to reconcile preclinical modeling of psychiatric neuropathology and clinical research. To this end, Pavlovian conditioning has provided a useful tool for investigating cognitive processes in both lab animal models and humans. This review focuses on trace conditioning, a form of Pavlovian conditioning typified by the insertion of a temporal gap (i.e., trace interval) between presentations of a conditioned stimulus (CS) and an unconditioned stimulus (US). This review aims to discuss pre-clinical and clinical work investigating the mnemonic processes recruited for trace conditioning. Much work suggests that trace conditioning involves unique neurocognitive mechanisms to facilitate formation of trace memories in contrast to standard Pavlovian conditioning. For example, the hippocampus and prefrontal cortex (PFC) appear to play critical roles in trace conditioning. Moreover, cognitive mechanistic accounts in human studies suggest that working memory and declarative memory processes are engaged to facilitate formation of trace memories. The aim of this review is to integrate cognitive and neurobiological accounts of trace conditioning from preclinical and clinical studies to examine involvement of working and declarative memory.
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Affiliation(s)
- David A Connor
- Department of Psychology, Neuroscience Program, Temple University, Philadelphia, PA 19122, United States
| | - Thomas J Gould
- Department of Psychology, Neuroscience Program, Temple University, Philadelphia, PA 19122, United States.
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15
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Kim N, Kong MS, Jo KI, Kim EJ, Choi JS. Increased tone-offset response in the lateral nucleus of the amygdala underlies trace fear conditioning. Neurobiol Learn Mem 2015; 126:7-17. [PMID: 26524504 DOI: 10.1016/j.nlm.2015.10.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Revised: 10/19/2015] [Accepted: 10/21/2015] [Indexed: 10/22/2022]
Abstract
Accumulating evidence suggests that the lateral nucleus of the amygdala (LA) stores associative memory in the form of enhanced neural response to the sensory input following classical fear conditioning in which the conditioned stimulus (CS) and the unconditioned stimulus (US) are presented in a temporally continuous manner. However, little is known about the role of the LA in trace fear conditioning where the CS and the US are separated by a temporal gap. Single-unit recordings of LA neurons before and after trace fear conditioning revealed that the short-latency activity to the CS offset, but not that to the onset, increased significantly and accompanied the conditioned fear response. The increased short-latency activity was evident in two aspects: the number of offset-responsive neurons was increased and the latency of the neuronal response to the CS offset was shortened. On the contrary, changes in the firing rate to either the onset or the offset were negligible following unpaired presentations of the CS and US. In sum, our results suggest that increased synaptic efficacy in the CS offset pathway in the LA might underlie the association between temporally distant stimuli in trace fear conditioning.
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Affiliation(s)
- Namsoo Kim
- Department of Psychology, Korea University, 5-1, Anam-dong, Seongbuk-gu, Seoul, Republic of Korea; Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
| | - Mi-Seon Kong
- Department of Psychology, Korea University, 5-1, Anam-dong, Seongbuk-gu, Seoul, Republic of Korea; Department of Psychology, University of Washington, Seattle, WA, USA
| | - Kyeong Im Jo
- Department of Psychology, Korea University, 5-1, Anam-dong, Seongbuk-gu, Seoul, Republic of Korea
| | - Eun Joo Kim
- Department of Psychology, Korea University, 5-1, Anam-dong, Seongbuk-gu, Seoul, Republic of Korea; Department of Psychology, University of Washington, Seattle, WA, USA
| | - June-Seek Choi
- Department of Psychology, Korea University, 5-1, Anam-dong, Seongbuk-gu, Seoul, Republic of Korea.
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16
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Chen VM, Foilb AR, Christianson JP. Inactivation of ventral hippocampus interfered with cued-fear acquisition but did not influence later recall or discrimination. Behav Brain Res 2015; 296:249-253. [PMID: 26386302 DOI: 10.1016/j.bbr.2015.09.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/31/2015] [Accepted: 09/07/2015] [Indexed: 11/19/2022]
Abstract
The ventral hippocampus (VH) is involved in the both the acquisition and recall of conditioned fear. Here, we tested the role of VH in acquisition and recall of a conditioned fear discrimination. Intra-VH vehicle or muscimol injections were made 1h prior to a CS+/CS- conditioning or prior to later recall. Vehicle treated rats exhibited discrimination with significantly greater freezing to the CS+ than to the CS- whereas muscimol treated rats did not freeze. Injections made before recall had no effect as both treatment groups displayed equal freezing in response to the CS+, and discrimination. While these results are consistent with several reports, the failure to influence fear discrimination upon recall appears to contrast with the hypothesized role of VH in recall of extinguished conditioned fear cues.
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Affiliation(s)
- Veronica M Chen
- Department of Psychology, Boston College, Chestnut Hill, MA 02467 USA
| | - Allison R Foilb
- Department of Psychology, Boston College, Chestnut Hill, MA 02467 USA
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17
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Hazan L, Gaisler-Salomon I. Glutaminase1 heterozygous mice show enhanced trace fear conditioning and Arc/Arg3.1 expression in hippocampus and cingulate cortex. Eur Neuropsychopharmacol 2014; 24:1916-24. [PMID: 25453483 DOI: 10.1016/j.euroneuro.2014.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 07/22/2014] [Accepted: 10/11/2014] [Indexed: 01/27/2023]
Abstract
Mice heterozygous for a mutation in the glutaminase (GLS1) gene (GLS1 HZ mice), with reduced glutamate recycling and release, display reduced hippocampal function as well as memory of contextual cues in a delay fear conditioning (FC) paradigm. Here, we asked whether this deficit reflects an inability to process contextual information or a selective alteration in salience attribution. In addition, we asked whether baseline and activity-induced hippocampal activity were diminished in GLS1 HZ mice. For this purpose, we manipulated the relative salience of the conditioned stimulus (CS) and contextual cues in FC tasks, and examined gene expression of the immediate early gene Arc (Arc/Arg3.1) in hippocampus and anterior cingulate cortex (ACC) following trace FC (tFC). The results indicate that GLS1 HZ mice succeed in processing contextual information when the salient CS is absent or less predictive. In addition, in the hippocampus-dependent tFC paradigm GLS1 HZ mice display enhanced CS learning. Furthermore, while baseline arc activation was reduced in GLS1 HZ mice in the hippocampus, in line with previous fMRI findings, it was enhanced in the hippocampus and anterior cingulate cortex following tFC. These findings suggest that GLS1 HZ mice have a pro-cognitive profile in the tFC paradigm, and this phenotype involves activation of both hippocampus and ACC. Taken together with previous work on the GLS1 HZ mouse, this study sheds light on the importance of glutamate transmission to memory processes that require the allocation of attentional resources, and extends our understanding of the underpinnings of attention deficits in SZ.
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Affiliation(s)
- Liran Hazan
- Department of Psychology, University of Haifa, Haifa 3498838, Israel
| | - Inna Gaisler-Salomon
- Department of Psychology, University of Haifa, Haifa 3498838, Israel; Department of Psychiatry, Columbia University, New York, NY 10032, USA.
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18
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Gilmartin MR, Balderston NL, Helmstetter FJ. Prefrontal cortical regulation of fear learning. Trends Neurosci 2014; 37:455-64. [PMID: 24929864 PMCID: PMC4119830 DOI: 10.1016/j.tins.2014.05.004] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/07/2014] [Accepted: 05/13/2014] [Indexed: 11/29/2022]
Abstract
The prefrontal cortex regulates the expression of fear based on previously learned information. Recently, this brain area has emerged as being crucial in the initial formation of fear memories, providing new avenues to study the neurobiology underlying aberrant learning in anxiety disorders. Here we review the circumstances under which the prefrontal cortex is recruited in the formation of memory, highlighting relevant work in laboratory animals and human subjects. We propose that the prefrontal cortex facilitates fear memory through the integration of sensory and emotional signals and through the coordination of memory storage in an amygdala-based network.
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Affiliation(s)
- Marieke R Gilmartin
- Department of Psychology, University of Wisconsin-Milwaukee, 2441 E. Hartford Ave., Milwaukee, WI 53211, USA; Department of Biomedical Sciences, Marquette University, 561 N 15th Street, Milwaukee, WI 53233, USA.
| | - Nicholas L Balderston
- Department of Psychology, University of Wisconsin-Milwaukee, 2441 E. Hartford Ave., Milwaukee, WI 53211, USA
| | - Fred J Helmstetter
- Department of Psychology, University of Wisconsin-Milwaukee, 2441 E. Hartford Ave., Milwaukee, WI 53211, USA
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19
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Thapa R, Sparks FT, Hanif W, Gulbrandsen T, Sutherland RJ. Recent memory for socially transmitted food preferences in rats does not depend on the hippocampus. Neurobiol Learn Mem 2014; 114:113-6. [PMID: 24862355 DOI: 10.1016/j.nlm.2014.05.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 04/23/2014] [Accepted: 05/16/2014] [Indexed: 10/25/2022]
Abstract
The standard model of systems consolidation holds that the hippocampus (HPC) is involved only in the initial storage and retrieval of a memory. With time hippocampal-neocortical interactions slowly strengthen the neocortical memory, ultimately enabling retrieval of the memory without the HPC. Key support for this idea comes from experiments measuring memory recall in the socially-transmitted food preference (STFP) task in rats. HPC damage within a day or two of STFP learning can abolish recall, but similar damage five or more days after learning has no effect. We hypothesize that disruption of cellular consolidation outside the HPC could contribute to the amnesia with recent memories, perhaps playing a more important role than the loss of HPC. This view predicts that intraHPC infusion of Tetrodotoxin (TTX), which can block conduction of action potentials from the lesion sites, will block the retrograde amnesia in the STFP task. Here we confirm the previously reported retrograde amnesia with neurotoxic HPC damage within the first day after learning, but show that co-administration of TTX with the neurotoxin blocks the retrograde amnesia despite very extensive HPC damage. These results indicate that HPC damage disrupts cellular consolidation of the recent memory elsewhere; STFP memory may not ever depend on the HPC.
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Affiliation(s)
- Rajat Thapa
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, 4401 University Drive W, Lethbridge, AB T1K 3M4, Canada.
| | - Fraser T Sparks
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, 4401 University Drive W, Lethbridge, AB T1K 3M4, Canada.
| | - Wahab Hanif
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, 4401 University Drive W, Lethbridge, AB T1K 3M4, Canada.
| | - Tine Gulbrandsen
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, 4401 University Drive W, Lethbridge, AB T1K 3M4, Canada.
| | - Robert J Sutherland
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, 4401 University Drive W, Lethbridge, AB T1K 3M4, Canada.
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20
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Colelli V, Campus P, Conversi D, Orsini C, Cabib S. Either the dorsal hippocampus or the dorsolateral striatum is selectively involved in consolidation of forced swim-induced immobility depending on genetic background. Neurobiol Learn Mem 2014; 111:49-55. [PMID: 24667495 DOI: 10.1016/j.nlm.2014.03.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 01/20/2014] [Accepted: 03/07/2014] [Indexed: 02/02/2023]
Abstract
Healthy subjects differ in the memory system they engage to learn dual-solution tasks. Both genotype and stress experience could contribute to this phenotypic variability. The present experiments tested whether the hippocampus and the dorsal striatum, the core nodes of two different memory systems, are differently involved in 24 h retention of a stress-associated memory in two genetically unrelated inbred strains of mice. Mice from both the C57BL/6J and the DBA/2J inbred strains showed progressive increase of immobility during 10 min exposure to forced swim (FS) and retrieved the acquired levels of immobility when tested 24h later. The pattern of c-fos immunostaining promoted by FS revealed activation of a large number of brain areas in both strains, including CA1 and CA3 fields of the hippocampus. However, only DBA/2J mice showed activation of the dorsolateral striatum (DLS). In addition, FS induced a positive correlation between c-fos expression in the amygdala and CA1 and CA3 in C57BL/6J mice whereas it induced a positive correlation between c-fos expression in the amygdala and DLS in DBA/2J mice. Finally, temporary post-training inactivation of the dorsal hippocampus, by local infusion of lidocaine, prevented 24h retention of immobility in C57BL/6J mice only, whereas inactivation of the DLS prevented retention in DBA/2J mice only. These findings support the view that genetic factors can determine whether the dorsal hippocampus or the DLS are selectively engaged to consolidate stress-related memory.
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Affiliation(s)
- V Colelli
- Dept. Psicologia, Center D.Bovet (CRIN), 'Sapienza' University of Rome, via dei Marsi 78, I-00185 Rome, Italy.
| | - P Campus
- Dept. Psicologia, Center D.Bovet (CRIN), 'Sapienza' University of Rome, via dei Marsi 78, I-00185 Rome, Italy.
| | - D Conversi
- Dept. Psicologia, Center D.Bovet (CRIN), 'Sapienza' University of Rome, via dei Marsi 78, I-00185 Rome, Italy; Fondazione Santa Lucia I.R.C.C.S., Via del Fosso di Fiorano 64, I-00143 Rome, Italy.
| | - C Orsini
- Dept. Psicologia, Center D.Bovet (CRIN), 'Sapienza' University of Rome, via dei Marsi 78, I-00185 Rome, Italy; Fondazione Santa Lucia I.R.C.C.S., Via del Fosso di Fiorano 64, I-00143 Rome, Italy.
| | - S Cabib
- Dept. Psicologia, Center D.Bovet (CRIN), 'Sapienza' University of Rome, via dei Marsi 78, I-00185 Rome, Italy; Fondazione Santa Lucia I.R.C.C.S., Via del Fosso di Fiorano 64, I-00143 Rome, Italy.
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21
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Raybuck JD, Lattal KM. Bridging the interval: theory and neurobiology of trace conditioning. Behav Processes 2014; 101:103-11. [PMID: 24036411 PMCID: PMC3943893 DOI: 10.1016/j.beproc.2013.08.016] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 07/25/2013] [Accepted: 08/09/2013] [Indexed: 12/26/2022]
Abstract
An early finding in the behavioral analysis of learning was that conditioned responding weakens as the conditioned stimulus (CS) and unconditioned stimulus (US) are separated in time. This "trace" conditioning effect has been the focus of years of research in associative learning. Theoretical accounts of trace conditioning have focused on mechanisms that allow associative learning to occur across long intervals between the CS and US. These accounts have emphasized degraded contingency effects, timing mechanisms, and inhibitory learning. More recently, study of the neurobiology of trace conditioning has shown that even a short interval between the CS and US alters the circuitry recruited for learning. Here, we review some of the theoretical and neurobiological mechanisms underlying trace conditioning with an emphasis on recent studies of trace fear conditioning. Findings across many studies have implications not just for how we think about time and conditioning, but also for how we conceptualize fear conditioning in general, suggesting that circuitry beyond the usual suspects needs to be incorporated into current thinking about fear, learning, and anxiety.
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Affiliation(s)
- Jonathan D Raybuck
- Department of Behavioral Neuroscience, Oregon Health & Science University, United States.
| | - K Matthew Lattal
- Department of Behavioral Neuroscience, Oregon Health & Science University, United States.
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