LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 165

Search options

  1. Article ; Online: Sex differences in contextual fear learning and generalization: a behavioral and computational analysis of hippocampal functioning.

    Trott, Jeremy M / Krasne, Franklin B / Fanselow, Michael S

    Learning & memory (Cold Spring Harbor, N.Y.)

    2022  Volume 29, Issue 9, Page(s) 283–296

    Abstract: There are sex differences in anxiety disorders with regard to occurrence and severity of episodes such that females tend to experience more frequent and more severe episodes. Contextual fear learning and generalization are especially relevant to anxiety ... ...

    Abstract There are sex differences in anxiety disorders with regard to occurrence and severity of episodes such that females tend to experience more frequent and more severe episodes. Contextual fear learning and generalization are especially relevant to anxiety disorders, which are often defined by expressing fear and/or anxiety in safe contexts. In contextual fear conditioning, a representation of the context must first be created, and then that representation must be paired with an aversive consequence. With some variation, the experiments presented here use a 3-d procedure in which day 1 consists of pre-exposure to the to-be-shocked context, day 2 consists of a single context-shock pairing after some placement-to-shock interval (PSI), and day 3 consists of testing in either the same or a novel context. With shorter pre-exposure periods, male rats showed more contextual fear, consistent with previous literature; however, after longer pre-exposure periods, female rats showed greater contextual fear. Additionally, while pre-exposure and PSI are both periods of time prior to the shock, it was found that they were not equivalent to each other. Animals with 120 sec of pre-exposure and a 30-sec PSI show a differential level and time course of fear expression than animals who received no pre-exposure and a 150-sec PSI, and this further depended on sex of the rat. Additionally, an experiment comparing recently versus remotely acquired contextual fear was run. Males were again shown to have greater contextual fear at both time points, and this contextual fear incubated/increased over time in males but not females. To facilitate identification of what processes caused sex differences, we used BaconX, a conceptual and computational model of hippocampal contextual learning. Computational simulations using this model predicted many of our key findings. Furthermore, these simulations suggest potential mechanisms with regard to hippocampal computation; namely, an increased feature sampling rate in males, which may account for the sex differences presented here and in prior literature.
    MeSH term(s) Animals ; Behavior, Animal ; Fear ; Female ; Generalization, Psychological ; Hippocampus ; Male ; Rats ; Sex Characteristics
    Language English
    Publishing date 2022-09-02
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 1204777-6
    ISSN 1549-5485 ; 1072-0502
    ISSN (online) 1549-5485
    ISSN 1072-0502
    DOI 10.1101/lm.053515.121
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: Social support and fear-inhibition: an examination of underlying neural mechanisms.

    Hornstein, E A / Leschak, C J / Parrish, M H / Byrne-Haltom, K E / Fanselow, M S / Craske, M G / Eisenberger, N I

    Social cognitive and affective neuroscience

    2024  Volume 19, Issue 1

    Abstract: Recent work has demonstrated that reminders of those we are closest to have a unique combination of effects on fear learning and represent a new category of fear inhibitors, termed prepared fear suppressors. Notably, social-support-figure images have ... ...

    Abstract Recent work has demonstrated that reminders of those we are closest to have a unique combination of effects on fear learning and represent a new category of fear inhibitors, termed prepared fear suppressors. Notably, social-support-figure images have been shown to resist becoming associated with fear, suppress conditional-fear-responding and lead to long-term fear reduction. Due to the novelty of this category, understanding the underlying neural mechanisms that support these unique abilities of social-support-reminders has yet to be investigated. Here, we examined the neural correlates that enable social-support-reminders to resist becoming associated with fear during a retardation-of-acquisition test. We found that social-support-figure-images (vs stranger-images) were less readily associated with fear, replicating prior work, and that this effect was associated with decreased amygdala activity and increased ventromedial prefrontal cortex (VMPFC) activity for social-support-figure-images (vs stranger-images), suggesting that social-support-engagement of the VMPFC and consequent inhibition of the amygdala may contribute to unique their inhibitory effects. Connectivity analyses supported this interpretation, showing greater connectivity between the VMPFC and left amygdala for social-support-figure-images (vs stranger-images).
    MeSH term(s) Humans ; Magnetic Resonance Imaging/methods ; Fear/physiology ; Prefrontal Cortex/diagnostic imaging ; Prefrontal Cortex/physiology ; Amygdala/diagnostic imaging ; Amygdala/physiology ; Social Support ; Extinction, Psychological/physiology
    Language English
    Publishing date 2024-01-12
    Publishing country England
    Document type Journal Article
    ZDB-ID 2236933-8
    ISSN 1749-5024 ; 1749-5016
    ISSN (online) 1749-5024
    ISSN 1749-5016
    DOI 10.1093/scan/nsae002
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article: Exposure Therapy for Post-Traumatic Stress Disorder: Factors of Limited Success and Possible Alternative Treatment.

    Markowitz, Sara / Fanselow, Michael

    Brain sciences

    2020  Volume 10, Issue 3

    Abstract: Recent research indicates that there is mixed success in using exposure therapies on patients with post-traumatic stress disorder (PTSD). Our study argues that there are two major reasons for this: The first is that there are nonassociative aspects of ... ...

    Abstract Recent research indicates that there is mixed success in using exposure therapies on patients with post-traumatic stress disorder (PTSD). Our study argues that there are two major reasons for this: The first is that there are nonassociative aspects of PTSD, such as hyperactive amygdala activity, that cannot be attenuated using the exposure therapy; The second is that exposure therapy is conceptualized from the theoretical framework of Pavlovian fear extinction, which we know is heavily context dependent. Thus, reducing fear response in a therapist's office does not guarantee reduced response in other situations. This study also discusses work relating to the role of the hippocampus in context encoding, and how these findings can be beneficial for improving exposure therapies.
    Language English
    Publishing date 2020-03-13
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2651993-8
    ISSN 2076-3425
    ISSN 2076-3425
    DOI 10.3390/brainsci10030167
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: Anxiety, fear, panic: An approach to assessing the defensive behavior system across the predatory imminence continuum.

    Hoffman, Ann N / Trott, Jeremy M / Makridis, Anna / Fanselow, Michael S

    Learning & behavior

    2022  Volume 50, Issue 3, Page(s) 339–348

    Abstract: In order to effectively thwart predation, antipredator defensive behaviors must be matched to the current spatio-temporal relationship to the predator. We have proposed a model where different defensive responses are organized along a predatory imminence ...

    Abstract In order to effectively thwart predation, antipredator defensive behaviors must be matched to the current spatio-temporal relationship to the predator. We have proposed a model where different defensive responses are organized along a predatory imminence continuum (PIC). The PIC is a behavior system organized as a sequence of innately programmed behavioral modes, each representing a different interaction with the predator or threat. Ranging from low threat to predator contact, the PIC categorizes defense modes as pre-encounter, post-encounter, and circa-strike, corresponding to states of anxiety, fear, and panic, respectively. This experiment examined if the same significant stressor caused overexpression of all defensive responses along the PIC, including anxiety-like behavior, freezing, and panic-like responses. Female and male mice were exposed to acute stress that consisted of a series of ten pseudorandomly presented unsignaled footshocks (or no shocks). Mice were subsequently tested on a battery of tasks to assess stress effects on pre-encounter (anxiety-like), post-encounter (fear), and circa-strike (panic-like) behaviors. Results revealed that following stress, mice exhibited increased anxiety-like behavior shown through reduced average velocity within a modified open field. Furthermore, stressed mice showed increased fear following a single footshock in a new context as well as an increase in reactivity to white noise in the original stress context, with stressed mice exhibiting a more robust circa-strike-like response than controls. Therefore, significant stress exposure influenced the defensive states of anxiety, fear, and panic across the predatory imminence continuum. This research could therefore reveal how such responses become maladaptive following traumatic stress in humans.
    MeSH term(s) Animals ; Anxiety ; Behavior, Animal/physiology ; Fear/physiology ; Female ; Humans ; Male ; Mice ; Predatory Behavior/physiology
    Language English
    Publishing date 2022-02-02
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2048665-0
    ISSN 1543-4508 ; 1543-4494
    ISSN (online) 1543-4508
    ISSN 1543-4494
    DOI 10.3758/s13420-021-00509-x
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Conditional and unconditional components of aversively motivated freezing, flight and darting in mice.

    Trott, Jeremy M / Hoffman, Ann N / Zhuravka, Irina / Fanselow, Michael S

    eLife

    2022  Volume 11

    Abstract: Fear conditioning is one of the most frequently used laboratory procedures for modeling learning and memory generally, and anxiety disorders in particular. The conditional response (CR) used in the majority of fear conditioning studies in rodents is ... ...

    Abstract Fear conditioning is one of the most frequently used laboratory procedures for modeling learning and memory generally, and anxiety disorders in particular. The conditional response (CR) used in the majority of fear conditioning studies in rodents is freezing. Recently, it has been reported that under certain conditions, running, jumping, or darting replaces freezing as the dominant CR. These findings raise both a critical methodological problem and an important theoretical issue. If only freezing is measured but rodents express their learning with a different response, then significant instances of learning, memory, or fear may be missed. In terms of theory, whatever conditions lead to these different behaviors may be a key to how animals transition between different defensive responses and different emotional states. In mice, we replicated these past results but along with several novel control conditions. Contrary to the prior conclusions, running and darting were primarily a result of nonassociative processes and were actually suppressed by associative learning. Darting and flight were taken to be analogous to nonassociative startle or alpha responses that are potentiated by fear. Additionally, associative processes had some impact on the topography of flight behavior. On the other hand, freezing was the purest reflection of associative learning. We also uncovered a rule that describes when these movements replace freezing: when afraid, freeze until there is a sudden novel change in stimulation, then burst into vigorous flight attempts. This rule may also govern the change from fear to panic.
    MeSH term(s) Animals ; Conditioning, Classical/physiology ; Fear/physiology ; Freezing ; Learning ; Mice
    Language English
    Publishing date 2022-05-26
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, N.I.H., Extramural
    ZDB-ID 2687154-3
    ISSN 2050-084X ; 2050-084X
    ISSN (online) 2050-084X
    ISSN 2050-084X
    DOI 10.7554/eLife.75663
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article ; Online: Sexually dimorphic muscarinic acetylcholine receptor modulation of contextual fear learning in the dentate gyrus.

    Yavas, Ersin / Trott, Jeremy M / Fanselow, Michael S

    Neurobiology of learning and memory

    2021  Volume 185, Page(s) 107528

    Abstract: Contextual fear conditioning, where the prevailing situational cues become associated with an aversive unconditional stimulus such as electric shock, is sexually dimorphic. Males typically show higher levels of fear than females. There are two components ...

    Abstract Contextual fear conditioning, where the prevailing situational cues become associated with an aversive unconditional stimulus such as electric shock, is sexually dimorphic. Males typically show higher levels of fear than females. There are two components to contextual fear conditioning. First the multiple cues that encompass the context must be integrated into a coherent representation, a process that requires the hippocampus. The second is that representation must be communicated to the basolateral amygdala where it can be associated with shock. If there is inadequate time for forming the representation prior to shock poor conditioning results and this is called the immediate shock deficit. One can isolate the contextual processing component, as well as alleviate the deficit, by providing an opportunity to explore the context without shock prior to the conditioning session. The purpose of the present study was to determine the extent to which cholinergic processes within the dentate gyrus of the hippocampus during contextual processing contribute to the sexual dimorphism. Clozapine-n-oxide (CNO) is a putatively inactive compound that acts only upon synthetic genetically engineered receptors. However, we found that CNO infused into the dentate gyrus prior to exploration eliminated the sexual dimorphism by selectively decreasing freezing in males to the level of females. Biological activity of CNO is usually attributed to metabolism of CNO to clozapine and we found that clozapine, and the muscarinic cholinergic antagonist, scopolamine, produced results similar to CNO, preferentially affecting males. On the other hand, the muscarinic agonist oxotremorine selectively impaired conditioning in females. Overall, the current experiments reveal significant off-target effects of CNO and implicate muscarinic cholinergic receptors in the dentate gyrus as a significant mediator of the sexual dimorphism in contextual fear conditioning.
    MeSH term(s) Animals ; Clozapine/pharmacology ; Conditioning, Classical/drug effects ; Conditioning, Classical/physiology ; Dentate Gyrus/anatomy & histology ; Dentate Gyrus/drug effects ; Dentate Gyrus/physiology ; Fear/physiology ; Female ; Male ; Rats ; Rats, Long-Evans ; Scopolamine/pharmacology ; Sex Characteristics
    Chemical Substances Scopolamine (DL48G20X8X) ; Clozapine (J60AR2IKIC)
    Language English
    Publishing date 2021-10-02
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 1223366-3
    ISSN 1095-9564 ; 1074-7427
    ISSN (online) 1095-9564
    ISSN 1074-7427
    DOI 10.1016/j.nlm.2021.107528
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article: Chronic intermittent ethanol exposure disrupts stress-related tripartite communication to impact affect-related behavioral selection in male rats.

    Munier, J J / Shen, S / Rahal, D / Hanna, A / Marty, V N / O'Neill, P R / Fanselow, M S / Spigelman, I

    Neurobiology of stress

    2023  Volume 24, Page(s) 100539

    Abstract: Alcohol use disorder (AUD) is characterized by loss of intake control, increased anxiety, and susceptibility to relapse inducing stressors. Both astrocytes and neurons contribute to behavioral and hormonal consequences of chronic intermittent ethanol ( ... ...

    Abstract Alcohol use disorder (AUD) is characterized by loss of intake control, increased anxiety, and susceptibility to relapse inducing stressors. Both astrocytes and neurons contribute to behavioral and hormonal consequences of chronic intermittent ethanol (CIE) exposure in animal models. Details on how CIE disrupts hypothalamic neuro-glial communication, which mediates stress responses are lacking. We conducted a behavioral battery (grooming, open field, reactivity to a single, uncued foot-shock, intermittent-access two-bottle choice ethanol drinking) followed by Ca
    Language English
    Publishing date 2023-04-20
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2816500-7
    ISSN 2352-2895
    ISSN 2352-2895
    DOI 10.1016/j.ynstr.2023.100539
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article: Neural organization of the defensive behavior system responsible for fear.

    Fanselow, M S

    Psychonomic bulletin & review

    2013  Volume 1, Issue 4, Page(s) 429–438

    Abstract: This paper applies the behavior systems approach to fear and defensive behavior, examining the neural circuitry controlling fear and defensive behavior from this vantage point. The defensive behavior system is viewed as having three modes that are ... ...

    Abstract This paper applies the behavior systems approach to fear and defensive behavior, examining the neural circuitry controlling fear and defensive behavior from this vantage point. The defensive behavior system is viewed as having three modes that are activated by different levels of fear. Low levels of fear promote pre-encounter defenses, such as meal-pattern reorganization. Moderate levels of fear activate post-encounter defenses. For the rat, freezing is the dominant post-encounter defensive response. Since this mode of defense is activated by learned fear, forebrain structures such as the amygdala play a critical role in its organization. Projections from the amygdala to the ventral periaqueductal gray activate freezing. Extremely high levels of fear, such as those provoked by physical contact, elicit the vigorous active defenses that compose the circa-strike mode. Midbrain structures such as the dorsolateral periaqueductal gray and the superior colliculus play a crucial role in organizing this mode of defense. Inhibitory interactions between the structures mediating circa-strike and post-encounter defense allow for the rapid switching between defensive modes as the threatening situation varies.
    Language English
    Publishing date 2013-11-08
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2031311-1
    ISSN 1531-5320 ; 1069-9384
    ISSN (online) 1531-5320
    ISSN 1069-9384
    DOI 10.3758/BF03210947
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article ; Online: The Origins and Organization of Vertebrate Pavlovian Conditioning.

    Fanselow, Michael S / Wassum, Kate M

    Cold Spring Harbor perspectives in biology

    2015  Volume 8, Issue 1, Page(s) a021717

    Abstract: Pavlovian conditioning is the process by which we learn relationships between stimuli and thus constitutes a basic building block for how the brain constructs representations of the world. We first review the major concepts of Pavlovian conditioning and ... ...

    Abstract Pavlovian conditioning is the process by which we learn relationships between stimuli and thus constitutes a basic building block for how the brain constructs representations of the world. We first review the major concepts of Pavlovian conditioning and point out many of the pervasive misunderstandings about just what conditioning is. This brings us to a modern redefinition of conditioning as the process whereby experience with a conditional relationship between stimuli bestows these stimuli with the ability to promote adaptive behavior patterns that did not occur before the experience. Working from this framework, we provide an in-depth analysis of two examples, fear conditioning and food-based appetitive conditioning, which include a description of the only partially overlapping neural circuitry of each. We also describe how these circuits promote the basic characteristics that define Pavlovian conditioning, such as error-correction-driven regulation of learning.
    MeSH term(s) Adaptation, Physiological ; Animals ; Conditioning, Classical ; Fear ; Learning ; Models, Biological ; Neural Pathways ; Reward ; Vertebrates/physiology
    Language English
    Publishing date 2015-11-09
    Publishing country United States
    Document type Journal Article ; Review
    ISSN 1943-0264
    ISSN (online) 1943-0264
    DOI 10.1101/cshperspect.a021717
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  10. Article ; Online: Control of contextual memory through interneuronal α5-GABA

    Zhu, Mengwen / Abdulzahir, Alifayaz / Perkins, Mark G / Chu, Chan C / Krause, Bryan M / Casey, Cameron / Lennertz, Richard / Ruhl, David / Hentschke, Harald / Nagarajan, Rajasekar / Chapman, Edwin R / Rudolph, Uwe / Fanselow, Michael S / Pearce, Robert A

    PNAS nexus

    2023  Volume 2, Issue 4, Page(s) pgad065

    Abstract: γ-Aminobutyric acid type A receptors that incorporate α5 subunits (α5- ... ...

    Abstract γ-Aminobutyric acid type A receptors that incorporate α5 subunits (α5-GABA
    Language English
    Publishing date 2023-04-11
    Publishing country England
    Document type Journal Article
    ISSN 2752-6542
    ISSN (online) 2752-6542
    DOI 10.1093/pnasnexus/pgad065
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top