1
|
Simões AP, Portes MAM, Lopes CR, Vanz F, Lourenço VS, Pliássova A, Gaspar IL, Silva HB, Tomé ÂR, Canas PM, Prediger RD, Cunha RA. Adenosine A 2A receptors control generalization of contextual fear in rats. Transl Psychiatry 2023; 13:316. [PMID: 37828000 PMCID: PMC10570294 DOI: 10.1038/s41398-023-02613-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 09/14/2023] [Accepted: 09/21/2023] [Indexed: 10/14/2023] Open
Abstract
Fear learning is essential to survival, but traumatic events may lead to abnormal fear consolidation and overgeneralization, triggering fear responses in safe environments, as occurs in post-traumatic stress disorder (PTSD). Adenosine A2A receptors (A2AR) control emotional memory and fear conditioning, but it is not known if they affect the consolidation and generalization of fear, which was now investigated. We now report that A2AR blockade through systemic administration of the A2AR antagonist SCH58261 immediately after contextual fear conditioning (within the consolidation window), accelerated fear generalization. Conversely, A2AR activation with CGS21680 decreased fear generalization. Ex vivo electrophysiological recordings of field excitatory post-synaptic potentials (fEPSPs) in CA3-CA1 synapses and of population spikes in the lateral amygdala (LA), showed that the effect of SCH58261 is associated with a reversion of fear conditioning-induced decrease of long-term potentiation (LTP) in the dorsal hippocampus (DH) and with increased amplitude of LA LTP in conditioned animals. These data suggest that A2AR are engaged during contextual fear consolidation, controlling long-term potentiation mechanisms in both DH and LA during fear consolidation, impacting on fear generalization; this supports targeting A2AR during fear consolidation to control aberrant fear processing in PTSD and other fear-related disorders.
Collapse
Affiliation(s)
- Ana P Simões
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal
| | - Marina A M Portes
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal
- Department of Pharmacology, Graduate Program in Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil
| | - Cátia R Lopes
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal
| | - Felipe Vanz
- Department of Pharmacology, Graduate Program in Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil
| | - Vanessa S Lourenço
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal
| | - Anna Pliássova
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal
| | - Ingride L Gaspar
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal
| | - Henrique B Silva
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal
| | - Ângelo R Tomé
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal
- Faculty of Science and Technology, Department of Life Sciences, University of Coimbra, Coimbra, Portugal
| | - Paula M Canas
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal
| | - Rui D Prediger
- Department of Pharmacology, Graduate Program in Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil
| | - Rodrigo A Cunha
- CNC- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517, Coimbra, Portugal.
- Faculty of Medicine, University of Coimbra, 3004-504, Coimbra, Portugal.
- Multidisciplinary Institute of Aging (MIA-Portugal), University of Coimbra, 3004-504, Coimbra, Portugal.
| |
Collapse
|
2
|
Xiang G, Liu X, Wang J, Lu S, Yu M, Zhang Y, Sun B, Huang B, Lu XY, Li X, Zhang D. Peroxisome proliferator-activated receptor-α activation facilitates contextual fear extinction and modulates intrinsic excitability of dentate gyrus neurons. Transl Psychiatry 2023; 13:206. [PMID: 37322045 DOI: 10.1038/s41398-023-02496-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 05/06/2023] [Accepted: 05/30/2023] [Indexed: 06/17/2023] Open
Abstract
The dentate gyrus (DG) of the hippocampus encodes contextual information associated with fear, and cell activity in the DG is required for acquisition and extinction of contextual fear. However, the underlying molecular mechanisms are not fully understood. Here we show that mice deficient for peroxisome proliferator-activated receptor-α (PPARα) exhibited a slower rate of contextual fear extinction. Furthermore, selective deletion of PPARα in the DG attenuated, while activation of PPARα in the DG by local infusion of aspirin facilitated extinction of contextual fear. The intrinsic excitability of DG granule neurons was reduced by PPARα deficiency but increased by activation of PPARα with aspirin. Using RNA-Seq transcriptome we found that the transcription level of neuropeptide S receptor 1 (Npsr1) was tightly correlated with PPARα activation. Our results provide evidence that PPARα plays an important role in regulating DG neuronal excitability and contextual fear extinction.
Collapse
Affiliation(s)
- Guo Xiang
- Department of Neurosurgery, Qilu Hospital and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, 250012, China
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, 250012, China
| | - Xia Liu
- Department of Neurosurgery, Qilu Hospital and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, 250012, China
| | - Jiangong Wang
- Institute of Metabolic and Neuropsychiatric Disorders, Binzhou Medical University Hospital, Binzhou, 256600, China
| | - Shunshun Lu
- Department of Neurosurgery, Qilu Hospital and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, 250012, China
| | - Meng Yu
- Department of Neurosurgery, Qilu Hospital and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, 250012, China
| | - Yuhan Zhang
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, 250012, China
| | - Bin Sun
- National Glycoengineering Research Center, Shandong University, Jinan, 250012, China
| | - Bin Huang
- Department of Neurosurgery, Qilu Hospital and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, 250012, China
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, 250012, China
| | - Xin-Yun Lu
- Department of Neuroscience & Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Xingang Li
- Department of Neurosurgery, Qilu Hospital and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, 250012, China
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, 250012, China
| | - Di Zhang
- Department of Neurosurgery, Qilu Hospital and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, 250012, China.
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, 250012, China.
| |
Collapse
|
3
|
On making (and turning adaptive to) maladaptive aversive memories in laboratory rodents. Neurosci Biobehav Rev 2023; 147:105101. [PMID: 36804263 DOI: 10.1016/j.neubiorev.2023.105101] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/03/2023] [Accepted: 02/14/2023] [Indexed: 02/18/2023]
Abstract
Fear conditioning and avoidance tasks usually elicit adaptive aversive memories. Traumatic memories are more intense, generalized, inflexible, and resistant to attenuation via extinction- and reconsolidation-based strategies. Inducing and assessing these dysfunctional, maladaptive features in the laboratory are crucial to interrogating posttraumatic stress disorder's neurobiology and exploring innovative treatments. Here we analyze over 350 studies addressing this question in adult rats and mice. There is a growing interest in modeling several qualitative and quantitative memory changes by exposing already stressed animals to freezing- and avoidance-related tests or using a relatively high aversive training magnitude. Other options combine aversive/fearful tasks with post-acquisition or post-retrieval administration of one or more drugs provoking neurochemical or epigenetic alterations reported in the trauma aftermath. It is potentially instructive to integrate these procedures and incorporate the measurement of autonomic and endocrine parameters. Factors to consider when defining the organismic and procedural variables, partially neglected aspects (sex-dependent differences and recent vs. remote data comparison) and suggestions for future research (identifying reliable individual risk and treatment-response predictors) are discussed.
Collapse
|
4
|
Markiewicz-Gospodarek A, Markiewicz R, Dobrowolska B, Rahnama M, Łoza B. Relationship of Neuropeptide S (NPS) with Neurocognitive, Clinical, and Electrophysiological Parameters of Patients during Structured Rehabilitation Therapy for Schizophrenia. J Clin Med 2022; 11:jcm11185266. [PMID: 36142912 PMCID: PMC9506378 DOI: 10.3390/jcm11185266] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/29/2022] [Accepted: 09/03/2022] [Indexed: 12/02/2022] Open
Abstract
Introduction: Neuropeptide S is a biomarker related to various neuropsychiatric and neurocognitive functions. Since the need to improve cognitive functions in schizophrenia is unquestionable, it was valuable to investigate the possible relationships of plasma levels of NPS with neurocognitive, psychopathological and EEG parameters in patients with schizophrenia. Aim: Relationships between the serum NPS level and neurocognitive, clinical, and electrophysiological parameters were investigated in patients diagnosed with schizophrenia who underwent structured rehabilitation therapy. Methods: Thirty-three men diagnosed with schizophrenia were randomized into two groups. The REH group (N16) consisted of patients who underwent structured rehabilitation therapy, the CON group (N17) continued its previous treatment. Additionally, the reference NPS serum results were checked in a group of healthy people (N15). In the study several tests assessing various neurocognitive functions were used: d2 Sustained-Attention Test (d2), Color Trails Test (CTT), Beck Cognitive Insight Scale (BCIS), Acceptance of Illness Scale (AIS), and General Self-Efficacy Scale (GSES). The clinical parameters were measured with Positive and Negative Syndrome Scale (PANSS) and electrophysiological parameters were analyzed with auditory evoked potentials (AEPs) and quantitative electroencephalography (QEEG). The NPS, neurocognitive, clinical, and electrophysiological results of REH and CON groups were recorded at the beginning (T1) and after a period of 3 months (T2). Results: A decreased level of NPS was associated with the improvement in specific complex indices of d2 and BCIS neurocognitive tests, as well as the improvement in the clinical state (PANSS). No correlation was observed between the level of NPS and the results of AEPs and QEEG measurements. Conclusions: A decreased level of NPS is possibly related to the improvement in metacognition and social cognition domains, as well as to clinical improvement during the rehabilitation therapy of patients with schizophrenia.
Collapse
Affiliation(s)
| | - Renata Markiewicz
- Department of Neurology, Neurological and Psychiatric Nursing, Medical University of Lublin, 20-093 Lublin, Poland
| | - Beata Dobrowolska
- Department of Holistic Care and Management in Nursing, Medical University of Lublin, 20-081 Lublin, Poland
| | - Mansur Rahnama
- Department of Oral Surgery, Medical University of Lublin, 20-093 Lublin, Poland
| | - Bartosz Łoza
- Department of Psychiatry, Medical University of Warsaw, 02-091 Warsaw, Poland
| |
Collapse
|
5
|
Relationship of Neuropeptide S with Clinical and Metabolic Parameters of Patients during Rehabilitation Therapy for Schizophrenia. Brain Sci 2022; 12:768. [PMID: 35741653 PMCID: PMC9221542 DOI: 10.3390/brainsci12060768&set/a 869781119+878628306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
Neuropeptide S (NPS) is a factor associated with the central regulation of body weight, stress, anxiety, learning, memory consolidation, wakefulness-sleep cycle, and anti-inflammatory and neuroplastic effects. Its stress-reducing, anti-anxiety, arousal without anxiety, and pro-cognitive effects represent an interesting option for the treatment of neuropsychiatric disorders. The purpose of the study was to examine the potential associations of NPS levels in the blood with clinical and metabolic parameters during the rehabilitation therapy of patients with schizophrenia. Thirty-three male subjects diagnosed with schizophrenia were randomly divided into two groups. The rehabilitation group (REH, N16) consisted of patients who were subjected to structured, 3-month intensive rehabilitation therapy, and the control group (CON, N17) consisted of patients who were subjected to a standard support mechanism. Both groups continued their pharmacological treatment as usual. The NPS concentration, as well as clinical and metabolic parameters, were compared in both groups. Additionally, a group of healthy (H) males (N15) was tested for NPS reference scores. To look for the specificity and selectivity of the NPS relationship with clinical results, various factor models of the positive and negative syndrome scale (PANSS) were analyzed, including the original PANSS 2/3 model, its modified four-factor version, the male-specific four-factor model, and two five-factorial models validated in large groups in clinical and multi-ethnic studies. Results and conclusions: (1) Structured rehabilitation therapy, compared to unstructured supportive therapy, significantly reduced the level of schizophrenia disorders defined by various factor models derived from PANSS. (2) The clinical improvement within the 3-month rehabilitation therapy course was correlated with a significant decrease in neuropeptide S (NPS) serum level. (3) The excitement/Hostility (E/H) factor, which included schizophrenic symptoms of the psychotic disorganization, was specific and selective for the reduction in serum NPS, which was stable across all analyzed factor models. (4) The long-term relationship between serum NPS and clinical factors was not accompanied by basic metabolic parameters.
Collapse
|
6
|
Relationship of Neuropeptide S with Clinical and Metabolic Parameters of Patients during Rehabilitation Therapy for Schizophrenia. Brain Sci 2022. [DOI: 10.3390/brainsci12060768
expr 958893762 + 814326274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
Neuropeptide S (NPS) is a factor associated with the central regulation of body weight, stress, anxiety, learning, memory consolidation, wakefulness–sleep cycle, and anti-inflammatory and neuroplastic effects. Its stress-reducing, anti-anxiety, arousal without anxiety, and pro-cognitive effects represent an interesting option for the treatment of neuropsychiatric disorders. The purpose of the study was to examine the potential associations of NPS levels in the blood with clinical and metabolic parameters during the rehabilitation therapy of patients with schizophrenia. Thirty-three male subjects diagnosed with schizophrenia were randomly divided into two groups. The rehabilitation group (REH, N16) consisted of patients who were subjected to structured, 3-month intensive rehabilitation therapy, and the control group (CON, N17) consisted of patients who were subjected to a standard support mechanism. Both groups continued their pharmacological treatment as usual. The NPS concentration, as well as clinical and metabolic parameters, were compared in both groups. Additionally, a group of healthy (H) males (N15) was tested for NPS reference scores. To look for the specificity and selectivity of the NPS relationship with clinical results, various factor models of the positive and negative syndrome scale (PANSS) were analyzed, including the original PANSS 2/3 model, its modified four-factor version, the male-specific four-factor model, and two five-factorial models validated in large groups in clinical and multi-ethnic studies. Results and conclusions: (1) Structured rehabilitation therapy, compared to unstructured supportive therapy, significantly reduced the level of schizophrenia disorders defined by various factor models derived from PANSS. (2) The clinical improvement within the 3-month rehabilitation therapy course was correlated with a significant decrease in neuropeptide S (NPS) serum level. (3) The excitement/Hostility (E/H) factor, which included schizophrenic symptoms of the psychotic disorganization, was specific and selective for the reduction in serum NPS, which was stable across all analyzed factor models. (4) The long-term relationship between serum NPS and clinical factors was not accompanied by basic metabolic parameters.
Collapse
|
7
|
Relationship of Neuropeptide S with Clinical and Metabolic Parameters of Patients during Rehabilitation Therapy for Schizophrenia. Brain Sci 2022; 12:brainsci12060768. [PMID: 35741653 PMCID: PMC9221542 DOI: 10.3390/brainsci12060768] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 06/07/2022] [Accepted: 06/09/2022] [Indexed: 01/09/2023] Open
Abstract
Neuropeptide S (NPS) is a factor associated with the central regulation of body weight, stress, anxiety, learning, memory consolidation, wakefulness–sleep cycle, and anti-inflammatory and neuroplastic effects. Its stress-reducing, anti-anxiety, arousal without anxiety, and pro-cognitive effects represent an interesting option for the treatment of neuropsychiatric disorders. The purpose of the study was to examine the potential associations of NPS levels in the blood with clinical and metabolic parameters during the rehabilitation therapy of patients with schizophrenia. Thirty-three male subjects diagnosed with schizophrenia were randomly divided into two groups. The rehabilitation group (REH, N16) consisted of patients who were subjected to structured, 3-month intensive rehabilitation therapy, and the control group (CON, N17) consisted of patients who were subjected to a standard support mechanism. Both groups continued their pharmacological treatment as usual. The NPS concentration, as well as clinical and metabolic parameters, were compared in both groups. Additionally, a group of healthy (H) males (N15) was tested for NPS reference scores. To look for the specificity and selectivity of the NPS relationship with clinical results, various factor models of the positive and negative syndrome scale (PANSS) were analyzed, including the original PANSS 2/3 model, its modified four-factor version, the male-specific four-factor model, and two five-factorial models validated in large groups in clinical and multi-ethnic studies. Results and conclusions: (1) Structured rehabilitation therapy, compared to unstructured supportive therapy, significantly reduced the level of schizophrenia disorders defined by various factor models derived from PANSS. (2) The clinical improvement within the 3-month rehabilitation therapy course was correlated with a significant decrease in neuropeptide S (NPS) serum level. (3) The excitement/Hostility (E/H) factor, which included schizophrenic symptoms of the psychotic disorganization, was specific and selective for the reduction in serum NPS, which was stable across all analyzed factor models. (4) The long-term relationship between serum NPS and clinical factors was not accompanied by basic metabolic parameters.
Collapse
|
8
|
Formation of False Context Fear Memory Is Regulated by Hypothalamic Corticotropin-Releasing Factor in Mice. Int J Mol Sci 2022; 23:ijms23116286. [PMID: 35682965 PMCID: PMC9181353 DOI: 10.3390/ijms23116286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 05/29/2022] [Accepted: 05/30/2022] [Indexed: 12/10/2022] Open
Abstract
Traumatic events frequently produce false fear memories. We investigated the effect of hypothalamic corticotropin-releasing factor (CRF) knockdown (Hy-Crf-KD) or overexpression (Hy-CRF-OE) on contextual fear memory, as fear stress-released CRF and hypothalamic-pituitary-adrenal axis activation affects the memory system. Mice were placed in a chamber with an electric footshock as a conditioning stimulus (CS) in Context A, then exposed to a novel chamber without CS, as Context B, at 3 h (B-3h) or 24 h (B-24h). The freezing response in B-3h was intensified in the experimental mice, compared to control mice not exposed to CS, indicating that a false fear memory was formed at 3 h. The within-group freezing level at B-24h was higher than that at B-3h, indicating that false context fear memory was enhanced at B-24h. The difference in freezing levels between B-3h and B-24h in Hy-Crf-KD mice was larger than that of controls. In Hy-CRF-OE mice, the freezing level at B-3h was higher than that of control and Hy-Crf-KD mice, while the freezing level in B-24h was similar to that in B-3h. Locomotor activity before CS and freezing level during CS were similar among the groups. Therefore, we hypothesized that Hy-Crf-KD potentiates the induction of false context fear memory, while Hy-CRF-OE enhances the onset of false fear memory formation.
Collapse
|
9
|
Tobinski AM, Rappeneau V. Role of the Neuropeptide S System in Emotionality, Stress Responsiveness and Addiction-Like Behaviours in Rodents: Relevance to Stress-Related Disorders. Pharmaceuticals (Basel) 2021; 14:ph14080780. [PMID: 34451877 PMCID: PMC8400992 DOI: 10.3390/ph14080780] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/02/2021] [Accepted: 08/04/2021] [Indexed: 12/22/2022] Open
Abstract
The neuropeptide S (NPS) and its receptor (NPSR1) have been extensively studied over the last two decades for their roles in locomotion, arousal/wakefulness and anxiety-related and fear-related behaviours in rodents. However, the possible implications of the NPS/NPSR1 system, especially those of the single nucleotide polymorphism (SNP) rs324981, in stress-related disorders and substance abuse in humans remain unclear. This is possibly due to the fact that preclinical and clinical research studies have remained separated, and a comprehensive description of the role of the NPS/NPSR1 system in stress-relevant and reward-relevant endpoints in humans and rodents is lacking. In this review, we describe the role of the NPS/NPSR1 system in emotionality, stress responsiveness and addiction-like behaviour in rodents. We also summarize the alterations in the NPS/NPSR1 system in individuals with stress-related disorders, as well as the impact of the SNP rs324981 on emotion, stress responses and neural activation in healthy individuals. Moreover, we discuss the therapeutic potential and possible caveats of targeting the NPS/NPSR1 system for the treatment of stress-related disorders. The primary goal of this review is to highlight the importance of studying some rodent behavioural readouts modulated by the NPS/NPSR1 system and relevant to stress-related disorders.
Collapse
|
10
|
Dissociative Effects of Neuropeptide S Receptor Deficiency and Nasal Neuropeptide S Administration on T-Maze Discrimination and Reversal Learning. Pharmaceuticals (Basel) 2021; 14:ph14070643. [PMID: 34358069 PMCID: PMC8308873 DOI: 10.3390/ph14070643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/04/2021] [Accepted: 06/21/2021] [Indexed: 11/17/2022] Open
Abstract
Cognitive flexibility refers to the ability to modify learned behavior in response to changes in the environment. In laboratory rodents, cognitive flexibility can be assessed in reversal learning, i.e., the change of contingencies, for example in T-maze discrimination learning. The present study investigated the role of the neuropeptide S (NPS) system in cognitive flexibility. In the first experiment, mice deficient of NPS receptors (NPSR) were tested in T-maze discrimination and reversal learning. In the second experiment, C57BL/6J mice were tested in the T-maze after nasal administration of NPS. Finally, the effect of nasal NPS on locomotor activity was evaluated. NPSR deficiency positively affected the acquisition of T-maze discrimination but had no effects on reversal learning. Nasal NPS administration facilitated reversal learning and supported an allocentric learning strategy without affecting acquisition of the task or locomotor activity. Taken together, the present data show that the NPS system is able to modulate both acquisition of T-maze discrimination and its reversal learning. However, NPSR deficiency only improved discrimination learning, while nasal NPS administration only improved reversal learning, i.e., cognitive flexibility. These effects, which at first glance appear to be contradictory, could be due to the different roles of the NPS system in the brain regions that are important for learning and cognitive flexibility.
Collapse
|
11
|
Acute stress leaves fear generalization in healthy individuals intact. COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2021; 21:372-389. [PMID: 33629258 PMCID: PMC8121734 DOI: 10.3758/s13415-021-00874-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 02/01/2021] [Indexed: 11/24/2022]
Abstract
Because threatening situations often occur in a similar manner, the generalization of fear to similar situations is adaptive and can avoid harm to the organism. However, the overgeneralization of fear to harmless stimuli is maladaptive and assumed to contribute to anxiety disorders. Thus, elucidating factors that may modulate fear (over)generalization is important. Based on the known effects of acute stress on learning, which are at least partly due to noradrenergic arousal, we investigated whether stress may promote fear overgeneralization and whether we could counteract this effect by reducing noradrenergic arousal. In a placebo-controlled, double-blind, between-subjects design, 120 healthy participants underwent a fear-conditioning procedure on Day 1. Approximately 24 hours later, participants received orally either a placebo or the beta-adrenergic receptor antagonist propranolol and were exposed to a stress or control manipulation before they completed a test of fear generalization. Skin conductance responses as well as explicit rating data showed a successful acquisition of conditioned fear on Day 1 and a pronounced fear generalization 24 hours later. Although physiological data confirmed the successful stress manipulation and reduction of noradrenergic arousal, the extent of fear generalization remained unaffected by stress and propranolol. The absence of a stress effect on fear generalization was confirmed by a second study and a Bayesian analysis across both data sets. Our findings suggest that acute stress leaves fear generalization processes intact, at least in a sample of healthy, young individuals.
Collapse
|
12
|
Kolodziejczyk MH, Faesel N, Koch M, Fendt M. Sociability and extinction of conditioned social fear is affected in neuropeptide S receptor-deficient mice. Behav Brain Res 2020; 393:112782. [DOI: 10.1016/j.bbr.2020.112782] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/09/2020] [Accepted: 06/17/2020] [Indexed: 01/16/2023]
|