Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 125
Filtrer
1.
Ophthalmologie ; 2024 Jul 02.
Article de Allemand | MEDLINE | ID: mdl-38953924

RÉSUMÉ

CLINICAL FEATURES: The click phenomenon occurs when an acquired mechanical restriction of the elevation in adduction of the eye or of the extension of the finger/thumb, is forcefully overcome. The common cause is a nodule either of the superior oblique tendon posterior to the trochlea in the case of a Jaensch-Brown syndrome or of the digital flexor tendon anterior to the A1 annular pulley in the case of a trigger finger. Both locations share similar anatomical conditions for the development of the nodule and the pathomechanism of the click. RESULTS: From these identical findings in the eye and the hand in small children it can be assumed that the results from the studies of the hand in newborns and infants with a trigger thumb/finger are also applicable to the situation of the eye. 1. This motility disorder is not congenital. This is most likely due to an incomplete development at the time of birth of the sliding factors needed for a free passage of the tendon through the trochlea and the A1 annular pulley. 2. A distinction must be made between stages 0-3: stage 0 = no more restriction of the motility and no click phenomenon; stage 1 = forced active extension/elevation possible; stage 2 = only passive extension/elevation, each with a click phenomenon; stage 3 = no extension/elevation possible and no click phenomenon. 3. In most cases in early childhood there is a spontaneous complete recovery (75% after 6-7 years). In the eye this spontaneous course can only limitedly be shortened with motility exercises in combination with segmental occlusion. CONCLUSION: The click phenomenon is a symptom of stages 1 and 2 of an acquired mechanical restriction of the elevation in adduction of the eye or the extension of the finger/thumb. It should not be called a syndrome.

2.
Subst Abuse Treat Prev Policy ; 19(1): 22, 2024 Apr 12.
Article de Anglais | MEDLINE | ID: mdl-38610049

RÉSUMÉ

INTRODUCTION: Research has established natural recovery (NR) as an important pathway to substance use recovery. Studies investigating correlates of NR have mainly focused on demographic and substance use variables rather than life circumstances. This study seeks to better understand the phenomenon of natural recovery by (i) validating the international scientific literature concerning demographic and substance use indicators of NR in Flanders and (ii) assessing the additional explanatory power of recovery strengths and barriers during active addiction, controlling for demographic and substance use covariates. METHODS: A total of 343 persons in recovery from alcohol or drug use problems (≥ 3 months) completed an online cross-sectional survey in Flanders. Participants in NR and in recovery after following treatment were compared using multivariate linear regression models. Reasons for not following treatment were analyzed using inductive thematic analysis. RESULTS: Higher education level, lower severity of dependence, and cannabis use as the main problem substance (vs. alcohol) were statistically significant (p < 0.05) correlates of NR. When scores for the number of barriers and strengths associated with active addiction were added, barriers (but not strengths) were significantly associated with NR. When barrier items were individually tested, having untreated emotional or mental health problems, having a driver's license revoked and damaging property were statistically significant correlates. The most reported reason for not entering treatment was not experiencing any need to do so. CONCLUSION: The results highlight the importance of a holistic approach to recovery support across multiple life domains. Limitations and opportunities for further research are discussed.


Sujet(s)
Comportement toxicomaniaque , Cannabis , Troubles liés à une substance , Humains , Études transversales , Éthanol , Troubles liés à une substance/épidémiologie
3.
Exp Brain Res ; 242(6): 1421-1428, 2024 Jun.
Article de Anglais | MEDLINE | ID: mdl-38647701

RÉSUMÉ

Unilateral spatial neglect (USN) results from impaired attentional networks and can affect various sensory modalities, such as visual and somatosensory. The rodent medial agranular cortex (AGm), located in the medial part of the forebrain from rostral to caudal direction, is considered a region associated with spatial attention. The AGm selectively receives multisensory input with the rostral AGm receiving somatosensory input and caudal part receiving visual input. Our previous study showed slower recovery from neglect with anterior AGm lesion using the somatosensory neglect assessment. Conversely, the functional differences in spatial attention across the entire AGm locations (anterior, intermediate, and posterior parts) are unknown. Here, we investigated the relationship between the severity of neglect and various locations across the entire AGm in a mouse stroke model using a newly developed program-based analysis method that does not require human intervention. Among various positions of the lesions, the recovery from USN during recovery periods (postoperative day; POD 10-18) tended to be slower in cases with more rostral lesions in the AGm (r = - 0.302; p = 0.028). Moreover, the total number of arm entries and maximum moving speed did not significantly differ between before and after AGm infarction. According to these results, the anterior lesions may slowly recover from USN-like behavior, and there may be a weak association between the AGm infarct site and recovery rate. In addition, all unilateral focal infarctions in the AGm induced USN-like behavior without motor deficits.


Sujet(s)
Modèles animaux de maladie humaine , Troubles de la perception , Animaux , Troubles de la perception/physiopathologie , Troubles de la perception/étiologie , Mâle , Souris , Souris de lignée C57BL , Latéralité fonctionnelle/physiologie , Perception de l'espace/physiologie , Accident vasculaire cérébral/physiopathologie , Accident vasculaire cérébral/complications , Cortex cérébral/physiopathologie
4.
Anim Cogn ; 27(1): 11, 2024 Mar 02.
Article de Anglais | MEDLINE | ID: mdl-38429608

RÉSUMÉ

Optimal foraging theory suggests that animals make decisions which maximize their food intake per unit time when foraging, but the mechanisms animals use to track the value of behavioral alternatives and choose between them remain unclear. Several models for how animals integrate past experience have been suggested. However, these models make differential predictions for the occurrence of spontaneous recovery of choice: a behavioral phenomenon in which a hiatus from the experimental environment results in animals reverting to a behavioral allocation consistent with a reward distribution from the more distant past, rather than one consistent with their most recently experienced distribution. To explore this phenomenon and compare these models, three free-operant experiments with rats were conducted using a serial reversal design. In Phase 1, two responses (A and B) were baited with pellets on concurrent variable interval schedules, favoring option A. In Phase 2, lever baiting was reversed to favor option B. Rats then entered a delay period, where they were maintained at weight in their home cages and no experimental sessions took place. Following this delay, preference was assessed using initial responding in test sessions where levers were presented, but not baited. Models were compared in performance, including an exponentially weighted moving average, the Temporal Weighting Rule, and variants of these models. While the data provided strong evidence of spontaneous recovery of choice, the form and extent of recovery was inconsistent with the models under investigation. Potential interpretations are discussed in relation to both the decision rule and valuation functions employed.


Sujet(s)
Comportement de choix , Conditionnement opérant , Rats , Animaux , Comportement de choix/physiologie , Conditionnement opérant/physiologie , Récompense , Comportement animal
5.
Behav Res Ther ; 174: 104490, 2024 Mar.
Article de Anglais | MEDLINE | ID: mdl-38354451

RÉSUMÉ

Previous laboratory work has shown that induction of positive mood prior to fear extinction decreases the negative valence of the conditional stimulus (CS) and reduces reinstatement of fear. Before translating these insights to clinical practice, it is important to test this strategy in anxious individuals. Students with a high fear of public speaking (N = 62) were randomized to either a positive mood induction, a negative mood induction, or no induction control group. All participants performed two weekly sessions of virtual reality exposure and a 1-week follow-up test including a spontaneous recovery test and reinstatement test after a social rejection (unconditional stimulus). We used self-reported fear measures and skin conductance responses. We expected that the positive group, compared to the other groups, would evaluate the CS (i.e., speaking in front of an audience) as less negative following exposure and would show less spontaneous recovery and reinstatement of fear following a social rejection. Although mood was successfully manipulated, there were no group differences in CS valence following exposure. In all conditions, VR exposure successfully reduced public speaking fear, and these effects were stable at follow-up. In contrast with expectations, the positive group showed more spontaneous recovery of CS negative valence than the negative group. To conclude, we found no evidence that positive mood induction prior to exposure optimizes exposure effects for anxious individuals.


Sujet(s)
Extinction (psychologie) , Peur , Humains , Peur/physiologie , Extinction (psychologie)/physiologie , Parole , Conditionnement classique/physiologie , Anxiété/thérapie
6.
Q J Exp Psychol (Hove) ; 77(1): 14-28, 2024 Jan.
Article de Anglais | MEDLINE | ID: mdl-36912231

RÉSUMÉ

Extinction training has proved effective to diminish the expectancy of the aversive unconditioned stimulus (US). However, the negative valence of the conditioned stimulus (CS) may still stay intact. In fact, several studies have suggested that the CS negative valence may be a factor that promotes the return of fear. Our study focuses on the role of changes in the CS valence as a potential mechanism to reduce the spontaneous recovery of threat expectancies. To do that, we evaluated counterconditioning (CC), a technique aimed to reduce the CS negative valence by paring it with a positive stimulus and compared its efficacy to that of a novelty-facilitated extinction (NFE) and a standard extinction interventions. Using a 2-day protocol, participants first learned the relationship between a figure and an aversive sound, using a differential conditioning paradigm, and were then randomly assigned to one of three different groups. For the CC group, CS+ or cue A was paired with a positive US. The standard extinction group was exposed to cue A alone. For a third NFE group, cue A was followed by a neutral US. Finally, on the second day, spontaneous recovery was tested. Our findings did not provide evidence to suggest that CC could be more effective to prevent or reduce the return of threat expectancies or influence valence ratings when compared with NFE and standard extinction.


Sujet(s)
Conditionnement classique , Extinction (psychologie) , Humains , Peur , Apprentissage , Affect
7.
Int J Dev Neurosci ; 83(8): 740-752, 2023 Dec.
Article de Anglais | MEDLINE | ID: mdl-37771243

RÉSUMÉ

OBJECTIVES: Perinatal hypoxic-ischemic encephalopathy (HIE) is a condition that can lead to long-term cognitive, motor, and behavioral impairments in newborns. Although brain hypothermia therapy is currently the standard treatment for HIE, it does not provide complete neuroprotection. As a result, there is a need to explore additional therapies to enhance treatment outcomes. This study aims to investigate the potential role of Ginkgolide B (GB) in promoting neuroplasticity and facilitating spontaneous recovery after HIE. METHODS: In this study, we employed a neonatal rat model of HIE to investigate the effects of GB on spontaneous recovery. GB treatment was initiated 24 h after hypoxia and administered continuously for a duration of 14 days. We evaluated several outcome measures after the treatment period, including spontaneous behavioral recovery and brain repair. Additionally, we quantified the levels of netrin-1 in both plasma and the peri-ischemic zone after the occurrence of HIE. RESULTS: We found that GB treatment significantly facilitated spontaneous behavioral recovery in the HIE pups. Furthermore, cognitive function was restored, and brain tissue repair had a noticeable acceleration. We observed increased cell proliferation in the subventricular, stratum, and subgranular zones. Of particular interest, we observed elevated levels of netrin-1 in both plasma and the ischemic penumbra following GB treatment. CONCLUSION: Our findings suggest that GB promotes neuroplasticity and enhances spontaneous recovery in newborns affected by HIE. The observed upregulation of netrin-1 may be crucial in mediating these effects. These results highlight the promising potential of GB as a post-HIE therapy, particularly in enhancing spontaneous recovery and improving long-term outcomes.


Sujet(s)
Hypothermie provoquée , Hypoxie-ischémie du cerveau , Femelle , Grossesse , Rats , Animaux , Hypoxie-ischémie du cerveau/traitement médicamenteux , Nétrine-1 , Encéphale
8.
Physiol Behav ; 271: 114336, 2023 Nov 01.
Article de Anglais | MEDLINE | ID: mdl-37619817

RÉSUMÉ

Extinction learning is tremendously adaptive as it allows an animal to adjust their behavior in a changing environment. Yet, extinction is not without limitations and fear often reemerges over time (i.e. spontaneous recovery). Relative to adults, adolescent rodents and humans are particularly prone to spontaneous recovery following extinction. In this study, we aimed to address whether combining methods of fear regulation (extinction and conditioned inhibition) can facilitate extinction retention. Early adolescent (29 days old, n = 81) and adult (70 days old, n = 80) mice underwent extinction with or without a safety cue present. Safety cue presentations were systematically varied to overlap with or alternate with fear cue presentations. We found that initial safety learning was faster in adolescent mice. In addition, intermixing safety cues into extinction reduced spontaneous recovery during a test two weeks later. The decrease in spontaneous recovery relative to a standard extinction protocol was greater in adolescents than adults. Together, our findings provide initial evidence that safety learning may be inherently stronger during adolescence. These results inform the parameters by which conditioned safety and extinction learning may be merged to augment the inhibition of fear. While methods to enhance fear regulation are valuable for any age, the potential to do so during adolescence is particularly striking.


Sujet(s)
Signaux , Extinction (psychologie) , Adulte , Adolescent , Humains , Souris , Animaux , Extinction (psychologie)/physiologie , Conditionnement psychologique/physiologie , Conditionnement classique/physiologie , Apprentissage
9.
Drug Alcohol Depend ; 246: 109858, 2023 05 01.
Article de Anglais | MEDLINE | ID: mdl-37028106

RÉSUMÉ

Cues associated with alcohol use can readily enhance self-reported cravings for alcohol, which increases the likelihood of reusing alcohol. Understanding the neuronal mechanisms involved in alcohol-seeking behavior is important for developing strategies to treat alcohol use disorder. In all experiments, adult female alcohol-preferring (P) rats were exposed to three conditioned odor cues; CS+ associated with EtOH self-administration, CS- associated with the absence of EtOH (extinction training), and a CS0, a neutral stimulus. The data indicated that presentation of an excitatory conditioned cue (CS+) can enhance EtOH- seeking while the CS- can inhibit EtOH-seeking under multiple test conditions. Presentation of the CS+ activates a subpopulation of dopamine neurons within the interfascicular nucleus of the posterior ventral tegmental area (posterior VTA) and basolateral amygdala (BLA). Pharmacological inactivation of the BLA with GABA agonists inhibits the ability of the CS+ to enhance EtOH-seeking but does not alter context-induced EtOH-seeking or the ability of the CS- to inhibit EtOH-seeking. Presentation of the conditioned odor cues in a non-drug-paired environment indicated that presentation of the CS+ increased dopamine levels in the BLA. In contrast, presentation of the CS- decreased both glutamate and dopamine levels in the BLA. Further analysis revealed that presentation of a CS+ EtOH-associated conditioned cue activates GABA interneurons but not glutamate projection neurons. Overall, the data indicate that excitatory and inhibitory conditioned cues can contrarily alter EtOH-seeking behaviors and that different neurocircuitries are mediating these distinct cues in critical brain regions. Pharmacotherapeutics for craving should inhibit the CS+ and enhance the CS- neurocircuits.


Sujet(s)
Signaux , Neurochimie , Rats , Femelle , Animaux , Dopamine , Comportement de recherche de substances/physiologie , Éthanol/pharmacologie , Autoadministration , Conditionnement opérant/physiologie , Extinction (psychologie)
10.
Toxins (Basel) ; 15(4)2023 03 25.
Article de Anglais | MEDLINE | ID: mdl-37104181

RÉSUMÉ

Deoxynivalenol (DON) is one of the most prevalent food-associated mycotoxins, and is known to cause a variety of adverse health effects on human and animals. Upon oral exposure, the intestine is the main target organ of DON. The current study unraveled that DON exposure (2 mg/kg bw/day or 5 mg/kg bw/day) can significantly reshape the gut microbiota in a mouse model. The study characterized the specific gut microbial strains and genes changed after DON exposure and also investigated the recovery of the microbiota upon either 2 weeks daily prebiotic inulin administration or 2 weeks recovery without intervention after termination of DON exposure (spontaneous recovery). The results obtained reveal that DON exposure causes a shift in gut microorganisms, increasing the relative abundance of Akkermansia muciniphila, Bacteroides vulgatus, Hungatella hathewayi, and Lachnospiraceae bacterium 28-4, while the relative abundance of Mucispirillum schaedleri, Pseudoflavonifractor sp. An85, Faecalibacterium prausnitzii, Firmicutes bacterium ASF500, Flavonifractor plautii, Oscillibacter sp. 1-3, and uncultured Flavonifractor sp. decreased. Notably, DON exposure enhanced the prevalence of A. muciniphila, a species considered as a potential prebiotic in previous studies. Most of the gut microbiome altered by DON in the low- and high-dose exposure groups recovered after 2 weeks of spontaneous recovery. Inulin administration appeared to promote the recovery of the gut microbiome and functional genes after low-dose DON exposure, but not after high-dose exposure, at which changes were exacerbated by inulin-supplemented recovery. The results obtained help to better understand the effect of DON on the gut microbiome, and the gut microbiota's recovery upon termination of DON exposure.


Sujet(s)
Lactobacillales , Microbiote , Trichothécènes , Souris , Humains , Animaux , Métagénome , Inuline , Trichothécènes/toxicité , Prébiotiques
11.
Neurosci Lett ; 804: 137204, 2023 05 01.
Article de Anglais | MEDLINE | ID: mdl-36966963

RÉSUMÉ

Home cage condition influences the central nervous system of experimental animals. However, little is known about the effect of home cage size and bedding material on fear-related behaviors. Thus, in this study, the effects of home cage size (large or small) and/or bedding material (paper or wood) on acquisition, retrieval, extinction, and spontaneous recovery of contextual fear memory were investigated in both male and female mice. The present study demonstrated that males housed in small cages with wood bedding showed a low fear response during fear extinction when compared to males housed in small or large cages with paper bedding. In females, mice housed in small cages with wood bedding showed low fear response during fear conditioning and extinction when compared to mice housed in large cages with paper bedding. Moreover, small cages with wood bedding, but not small or large cages with paper bedding, prevented the spontaneous recovery of fear memory in females. Thus, home cage conditions, and particularly bedding material, influence contextual fear extinction and spontaneous recovery. This finding may help to obtain reproducibility of results by researchers and explain discrepancies of results among research groups.


Sujet(s)
Extinction (psychologie) , Peur , Animaux , Souris , Mâle , Femelle , Extinction (psychologie)/physiologie , Reproductibilité des résultats , Conditionnement psychologique , Literie et linges
12.
J Neurochem ; 165(4): 587-602, 2023 05.
Article de Anglais | MEDLINE | ID: mdl-36916413

RÉSUMÉ

Ischemic stroke triggers a cascade of events that facilitates neural protection and spontaneous recovery, which accounts for a major part of functional recovery. Despite the cellular and molecular facilitations on neural protection, the molecular mechanisms of spontaneous recovery have not been fully understood. Ca2+ -dependent activator protein for secretion 1 (CAPS1), a member of CAPS family, plays a major role in synaptic transmission and synaptic effectiveness by regulating vesicle exocytosis. Here, the molecular mechanism of CAPS1 in spontaneous recovery after ischemic stroke was studied. In this study, transient left middle cerebral artery occlusion (MCAO) was used as the ischemic stroke model. The whole brain magnetic resonance imaging (MRI) and neurological score analysis showed decreased infarct volume and neurological scores at 7 days as compared with 1 day after MCAO, suggesting the spontaneous recovery. Elisa and Western blot analysis showed elevated BDNF and CAPS1 expression levels in bilateral hippocampus at both 1 day and 3 days after MCAO. Then, inhibition of CAPS1 by adeno-associated virus (AAV) microinjection in the hippocampus attenuated the spontaneous recovery of both motor and memory impairment induced by MCAO. In addition, elevated p-TrkB levels were detected after MCAO, which were reduced by CAPS1-AAV microinjection, indicating that CAPS1 could induce BDNF secretion after ischemic stroke. Moreover, we found elevated combination of CAPS1 with dense core vesicles (DCV) in the hippocampus at both 1 day and 3 days after MCAO, which could also be inhibited by CAPS1-AAV microinjection, indicating the potential mechanism of CAPS1 in regulating BDNF release after MCAO. Finally, we found that CAPS1/BDNF signaling could influence the neurogenesis in the hippocampus after MCAO. In conclusion, CAPS1 regulates neurogenesis by up-regulating BDNF release in the hippocampus, which finally facilitate spontaneous recovery after ischemic stroke.


Sujet(s)
Encéphalopathie ischémique , Accident vasculaire cérébral ischémique , Accident vasculaire cérébral , Humains , Facteur neurotrophique dérivé du cerveau/métabolisme , Accident vasculaire cérébral ischémique/métabolisme , Encéphale/métabolisme , Encéphalopathie ischémique/métabolisme , Transduction du signal , Infarctus du territoire de l'artère cérébrale moyenne/métabolisme , Accident vasculaire cérébral/métabolisme
13.
Curr Biol ; 33(5): 838-848.e3, 2023 03 13.
Article de Anglais | MEDLINE | ID: mdl-36731465

RÉSUMÉ

Learned behavior can be suppressed by the extinction procedure. Such extinguished memory often returns spontaneously over time, making it difficult to treat diseases such as addiction. However, the biological mechanisms underlying such spontaneous recovery remain unclear. Here, we report that the extinguished reward memory in Drosophila recovers spontaneously because extinction training forms an aversive memory that can be actively forgotten via the Rac1/Dia pathway. Manipulating Rac1 activity does not affect sugar-reward memory and its immediate extinction effect but bidirectionally regulates spontaneous recovery-the decay process of extinction. Experiments using thermogenetic inhibition and functional imaging support that such extinction appears to be coded as an aversive experience. Genetic and pharmacological inhibition of formin Dia, a downstream effector of Rac1, specifically prevents spontaneous recovery after extinction in both behavioral performance and corresponding physiological traces. Together, our data suggest that spontaneous recovery is caused by active forgetting of the opposing extinction memory.


Sujet(s)
Conditionnement psychologique , Mémoire , Animaux , Mémoire/physiologie , Drosophila , Récompense
14.
Clin Otolaryngol ; 48(3): 395-402, 2023 05.
Article de Anglais | MEDLINE | ID: mdl-36640119

RÉSUMÉ

PURPOSE: Steroids comprise the mainstay of treatment for idiopathic sudden sensorineural hearing loss (ISSNHL). Since steroidal treatment was integrated to clinical practice guidelines, newly published no-treatment or placebo arms in clinical trials are scarce. To evaluate the effectiveness of steroidal treatment ± hyperbaric oxygen therapy, the data should be compared to spontaneous recovery. The aim of this paper is to find the most accurate spontaneous recovery rate, in the light of which, other treatment modalities should be judged. MATERIALS AND METHODS: Eligible studies published until July 2021 were identified through systematic searches of 'PubMed', 'Web of Science' and 'Google Scholar'. Retrospective studies and randomised/non-randomised control trials involving only adult participants (≥18 years) with ISSNHL, and placebo/no treatment were included. Only articles that used the American Academy of Otolaryngology-Head and Neck Surgery's diagnostic criteria for ISSNHL were included. RESULTS: 942 records initially identified, 166 duplicates and 753 articles were excluded based on article subject, title, and abstract. The full texts of 13 articles were reviewed. Seven studies were included for qualitative synthesis, five papers included in quantitative synthesis. 180 ears were included in pooled statistics. The pooled spontaneous recovery was 60.28% (95% confidence interval [CI] = 38.88%-79.94%) with a heterogeneity of 86.0% (95% CI = 69.4%-93.6%). CONCLUSIONS: Spontaneous recovery of ISSNHL should not be over-looked, as it may be close to 60%. This may have both clinical and research implications.


Sujet(s)
Surdité neurosensorielle , Perte auditive soudaine , Adulte , Humains , Études rétrospectives , Glucocorticoïdes/usage thérapeutique , Perte auditive soudaine/thérapie , Perte auditive soudaine/traitement médicamenteux , Surdité neurosensorielle/thérapie , Surdité neurosensorielle/traitement médicamenteux , Stéroïdes
15.
Learn Behav ; 51(3): 262-273, 2023 09.
Article de Anglais | MEDLINE | ID: mdl-36344750

RÉSUMÉ

Punishment and extinction are both effective methods of reducing instrumental responding and may involve similar learning mechanisms. To characterize the similarities and differences between them, we examined three well-established recovery or "relapse" effects -renewal, spontaneous recovery, and reacquisition - following either punishment or extinction of an instrumental response. In Experiment 1a, both punished and extinguished responses renewed to similar degrees following a context change at test (ABA renewal). In Experiment 1b, responding spontaneously recovered to similar degrees following punishment or extinction. In Experiment 2, responding was rapidly reacquired when the response was reinforced again following extinction but not following punishment, as predicted by the idea that the reinforcer delivered in reacquisition is part of the context of punishment, but not extinction. The results collectively suggest that both punishment and extinction produce similar context-dependent retroactive interference effects. More broadly, they also suggest that punished and extinguished responses may be equally likely to return following a change of context despite the intuition that punishment might provide a more extreme and effective means of suppressing behavior. To our knowledge, this is the first direct behavioral comparison of response recovery after punishment and extinction within individual experiments.


Sujet(s)
Conditionnement opérant , Punition , Animaux , Conditionnement opérant/physiologie , Extinction (psychologie)/physiologie , Mémoire
16.
Neuropharmacology ; 225: 109402, 2023 03 01.
Article de Anglais | MEDLINE | ID: mdl-36565854

RÉSUMÉ

(2R,6R)-Hydroxynorketamine (HNK), a ketamine metabolite, has been proposed as an ideal next-generation antidepressant due to its rapid-acting and long-lasting antidepression-relevant actions. Interestingly, recent studies have shown that (2R,6R)-HNK may have diverse impacts on memory formation. However, its effect on fear memory extinction is still unknown. In the present study, we assessed the effects of (2R,6R)-HNK on synaptic transmission and plasticity in the basolateral amygdala (BLA) and explored its actions on auditory fear memory extinction. Adult male C57BL/6J mice were used in this study. The extracellular electrophysiological recording was conducted to assay synaptic transmission and plasticity. The auditory fear conditioning paradigm was performed to test fear extinction. The results showed that (2R,6R)-HNK at 30 mg/kg increased the number of c-fos-positive cells in the BLA. Moreover, (2R,6R)-HNK enhanced the induction and maintenance of long-term potentiation (LTP) in the BLA in a dose-dependent manner (at 1, 10, and 30 mg/kg). In addition, (2R,6R)-HNK at 30 mg/kg and directly slice perfusion of (2R,6R)-HNK enhanced BLA synaptic transmission. Furthermore, intra-BLA application and systemic administration of (2R,6R)-HNK reduced the retrieval of recent fear memory and decreased the retrieval of remote fear memory. Both local and systemic (2R,6R)-HNK also inhibited the spontaneous recovery of remote fear memory. Taken together, these results indicated that (2R,6R)-HNK could regulate BLA synaptic transmission and plasticity and act through the BLA to modulate fear memory. The results revealed that (2R,6R)-HNK may be a potential drug to treat posttraumatic stress disorder (PTSD) patients.


Sujet(s)
Groupe nucléaire basolatéral , Souris , Animaux , Mâle , Extinction (psychologie) , Peur , Souris de lignée C57BL
17.
Neural Regen Res ; 18(5): 1084-1089, 2023 May.
Article de Anglais | MEDLINE | ID: mdl-36254997

RÉSUMÉ

Assessment of locomotion recovery in preclinical studies of experimental spinal cord injury remains challenging. We studied the CatWalk XT® gait analysis for evaluating hindlimb functional recovery in a widely used and clinically relevant thoracic contusion/compression spinal cord injury model in rats. Rats were randomly assigned to either a T9 spinal cord injury or sham laminectomy. Locomotion recovery was assessed using the Basso, Beattie, and Bresnahan open field rating scale and the CatWalk XT® gait analysis. To determine the potential bias from weight changes, corrected hindlimb (H) values (divided by the unaffected forelimb (F) values) were calculated. Six weeks after injury, cyst formation, astrogliosis, and the deposition of chondroitin sulfate glycosaminoglycans were assessed by immunohistochemistry staining. Compared with the baseline, a significant spontaneous recovery could be observed in the CatWalk XT® parameters max intensity, mean intensity, max intensity at%, and max contact mean intensity from 4 weeks after injury onwards. Of note, corrected values (H/F) of CatWalk XT® parameters showed a significantly less vulnerability to the weight changes than absolute values, specifically in static parameters. The corrected CatWalk XT® parameters were positively correlated with the Basso, Beattie, and Bresnahan rating scale scores, cyst formation, the immunointensity of astrogliosis and chondroitin sulfate glycosaminoglycan deposition. The CatWalk XT® gait analysis and especially its static parameters, therefore, seem to be highly useful in assessing spontaneous recovery of hindlimb function after severe thoracic spinal cord injury. Because many CatWalk XT® parameters of the hindlimbs seem to be affected by body weight changes, using their corrected values might be a valuable option to improve this dependency.

18.
Hepatol Int ; 16(6): 1390-1397, 2022 Dec.
Article de Anglais | MEDLINE | ID: mdl-36131224

RÉSUMÉ

OBJECTIVE: Outcome of pediatric acute liver failure (PALF) in countries with limited availability of LT is not well described. We evaluated the outcome and prognostic indicators of PALF in Malaysia where emergency LT for ALF is limited. METHODS: In this retrospective review on children < 18 years with PALF, we compared clinical and laboratory parameters between survival after supportive treatment and after LT or succumbed without LT. The predictive values of Liver Injury Unit (LIU; peak laboratory values for international normalized ratio [INR], ammonia, total bilirubin) and upon admission (aLIU) on outcome of PALF was evaluated using receiver operator characteristic (ROC) curves. RESULTS: Of 77 children (39 males [51%]; median age 2.8 years) with PALF, the overall survival was 55% (n = 42); 52% (n = 40) survived with supportive management, 2.6% (n = 2) after LT. As compared to children who survived without LT, children who had LT/died had lower hemoglobin, aspartate transferase, γ-glutamyl transpeptidase (GGT), and higher serum bilirubin, alkaline phosphatase, ammonia, and serum sodium (p < 0.05). On multivariate analysis, significant independent predictor for death or LT were peak bilirubin > 452 µmol/L and peak GGT < 96 IU/L. The C-index of LIU and aLIU score were 0.79 and 0.68, respectively, indicating that LIU score was a good model in predicting outcome of PALF. CONCLUSIONS: Overall survival of PALF remained poor. High peak bilirubin and low GGT predict poor outcome of PALF. LIU score is a good model in predicting outcome of PALF and maybe useful in selecting children for emergency LT.


Sujet(s)
Défaillance hépatique aigüe , Transplantation hépatique , Mâle , Enfant , Humains , Enfant d'âge préscolaire , Pronostic , Ammoniac , Transplantation hépatique/effets indésirables , Indice de gravité de la maladie , Défaillance hépatique aigüe/étiologie , Défaillance hépatique aigüe/thérapie , Bilirubine , Études rétrospectives
19.
Int J Mol Sci ; 23(16)2022 Aug 19.
Article de Anglais | MEDLINE | ID: mdl-36012600

RÉSUMÉ

Cannabidiol, the main non-psychotropic constituent of cannabis, has potential as a treatment for anxiety-related disorders since it reduces learned fear expression and enhances fear extinction. The return of fear over time after successful extinction and stress-induced extinction resistance are potential barriers to the treatment of these disorders with extinction-based psychological therapy. In two experiments using rats subjected to auditory fear conditioning, we determined the effects of systemic cannabidiol treatment on (1) delayed extinction and later spontaneous fear recovery, and (2) extinction resistance caused by immediate extinction (the immediate extinction deficit (IED)). In Experiment 1, cannabidiol was given before delayed extinction occurring 24 h after conditioning, with extinction recall and spontaneous fear recovery tested drug-free 1 and 21 days after extinction, respectively. We found that cannabidiol had no effect on extinction recall but it prevented spontaneous fear recovery. In Experiment 2, the IED procedure was first validated, with immediate extinction occurring 30 min after conditioning. We confirmed that immediate extinction impaired extinction recall, compared to delayed extinction. Next, cannabidiol was given before immediate or no extinction, with extinction recall tested drug-free the next day. We found that cannabidiol rescued the IED, which did not involve effects on fear memory consolidation. In summary, cannabidiol prevented spontaneous fear recovery after delayed extinction and ameliorated extinction resistance caused by immediate extinction. Although the pharmacological mechanisms underlying these effects remain to be determined, our results add to evidence indicating that cannabidiol might prove useful as an adjunct for potentiating the psychological treatment of anxiety-related disorders.


Sujet(s)
Cannabidiol , Peur , Animaux , Cannabidiol/pharmacologie , Conditionnement classique , Conditionnement psychologique , Extinction (psychologie) , Rats
20.
Cureus ; 14(5): e24989, 2022 May.
Article de Anglais | MEDLINE | ID: mdl-35719760

RÉSUMÉ

It Is well known that abdominal pain during pregnancy has a broad differential diagnosis, which includes spontaneous adrenal hemorrhage (SAH), a rarely reported phenomenon in the literature, defined as an acute hemorrhage into the adrenal gland during pregnancy in the absence of a clear cause. Physicians should have a high suspicion for it due to the potentially life-threatening complications, as they present usually with a non-specific presentation. We present a case of symptomatic SAH in the third trimester of pregnancy that was successfully managed conservatively.

SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE
...