1,721,059 research outputs found
The endocannabinoid system: An emotional buffer in the modulation of memory function
No full textExtensive evidence indicates that endocannabinoids modulate cognitive processes in animal models and human subjects. However, the results of endocannabinoid system manipulations on cognition have been contradictory. As for anxiety behavior, a duality has indeed emerged with regard to cannabinoid effects on memory for emotional experiences. Here we summarize findings describing cannabinoid effects on memory acquisition, consolidation, retrieval and extinction. Additionally, we review findings showing how the endocannabinoid system modulates memory function differentially, depending on the level of stress and arousal associated with the experimental context. Based on the evidence reviewed here, we propose that the endocannabinoid system is an emotional buffer that moderates the effects of environmental context and stress on cognitive processes. (C) 2013 Elsevier Inc. All rights reserved
The endocannabinoid system: a key modulator of stress effects on memory
Full text linkAs mentioned above, a large amount of evidence indicates that the
endocannabinoid system is crucially involved in the modulation of memory
consolidation for stressful experiences (Akirav, 2011; Campolongo et al, 2009;
Kano et al, 2009; Marsicano et al, 2009; Wotjak, 2005). Indeed previous findings
from our laboratory have demonstrated that CB1 receptor activation within the
BLA enhances memory consolidation. In particular, the cannabinoid agonist
WIN55,212-2, bilaterally infused into the BLA immediately after inhibitory
avoidance training, enhanced memory consolidation. Conversely, the CB1
receptor antagonist AM251 administered after training into the BLA dosedependently
impaired 48-h inhibitory avoidance retention (Campolongo et al,
2009). Based on these previous findings we hypothesized that after an aversive
experience endocannabinoids might be released within the BLA in order to
modulate the better storage of emotionally salient events
Interaction between cannabinoids and glucocorticoids in the modulation of recognition memory in rats
No full textCircadian regulation of memory under stress. Endocannabinoids matter
No full textOrganisms ranging from plants to higher mammals have developed 24-hour oscillation rhythms to optimize physiology to environmental changes and regulate a plethora of neuroendocrine and behavioral processes, including neurotransmitter and hormone regulation, stress response and learning and memory function. Compelling evidence indicates that a wide array of memory processes is strongly influenced by stress- and emotional arousal-activated neurobiological systems, including the endocannabinoid system which has been extensively shown to play an integral role in mediating stress effects on memory. Here, we review findings showing how circadian rhythms and time-of-day influence stress systems and memory performance. We report evidence of circadian regulation of memory under stress, focusing on the role of the endocannabinoid system and highlighting its circadian rhythmicity. Our discussion illustrates how the endocannabinoid system mediates stress effects on memory in a circadian-dependent fashion. We suggest that endocannabinoids might regulate molecular mechanisms that control memory function under circadian and stress influence, with potential important clinical implications for both neurodevelopmental disorders and psychiatric conditions involving memory impairments
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Sex-specific effects of endocannabinoid hydrolysis inhibition on fear memory dynamics
No full textFear extinction is an essential process for recovery from traumatic events. Endocannabinoids are importantly involved in modulating fear extinction and the recruitment of fear coping strategies in male rodents; however, little is understood about this regulation in females. Preclinical studies show that females prefer active fear coping strategies (darting), while males predominately exhibit passive fear responses (freezing). We examined potential sex differences of endocannabinoid modulation of fear memory extinction and fear coping responses in rats. We found that boosting endocannabinoid anandamide levels increased freezing and diminished darting in females to levels comparable to males, in early extinction learning and recall
Modulation of anxiety by the endocannabinoid anandamide signaling in the prefrontal cortex is dependent on the emotional arousal state
No full textMany people who suffer from anxiety disorders self-medicate with cannabis which seems to reduce anxiety. However, cannabis usage has also been shown to have the opposite effect and some people have reported feeling increased anxiety and depressive mood when using cannabis. Animal studies have indicated that cannabinoid drugs can cause these distinct opposite effects on anxiety behaviour depending on both the animal stress levels and the aversiveness of the environmental conditions. Furthermore, animal studies have shown the critical involvement of the prefrontal cortex (PFC) endocannabinoid system in the regulation of stress and anxiety behaviours. The goal of this study was to evaluate whether the endocannabinoid anandamide (AEA) and 2-arachidonoylglycerol (2-AG), in the PFC, differentially regulate anxiety behaviour depending on the level of environment-associated emotional arousal.
Sprague-Dawley rats were divided in two groups and tested for anxiety in the Elevated Plus Maze (EPM). To increase the level of environment-associated emotional arousal, one group was not handled or habituated to the experimental room and tested under high light condition (High-Arousal group; HA); the second group was extensively handled and habituated to the experimental room prior to the EPM and tested under red light condition (Low-Arousal group; LA). We evaluated the effects of intra-PFC administration of the AEA hydrolysis inhibitor URB597 or the 2-AG hydrolysis inhibitor KML29 on anxiety behavior. HA and LA rats were given bilateral intra-PFC administration of URB597 (10 ng/side), KML29 (0.2ug/side) or their vehicle 30 min prior to the EPM test. Rats were, then, sacrificed for brain dissection and histological analysis to assure proper cannula placement. As was expected, the LA group exhibited a significant lower anxiety behavioral profile as compared to the HA group in the EPM. We also found that URB597 decreased the anxiety response shown by LA rats as compared to the correspondent vehicle group, without affecting emotional behavior in the HA group. KML29 injections did not alter anxiety response in the LA or the HA group.
Taken together, these findings show how the endocannabinoid system is differentially activated to regulate anxiety response, depending on the level of the environment-associated emotional arousal and help to shed light on the neurobiological mechanism involved in the differential impact of stress on emotionality
Sex-specific effects of the endocannabinoid anandamide hydrolysis inhibition on fear memory dynamics
No full textPathologically impaired fear extinction is thought to contribute to the development and persistence of psychiatric disorders, such as post-traumatic stress disorder (PTSD). PTSD prevalence is twice as high in women as in men, with treatment efficacy also reflecting sex-differences. The mechanisms underlying sex-differences in fear coping responses may involve the endocannabinoid (eCB) system. Thus, the principal objective of this study was to investigate the role of the endocannabinoid anandamide (AEA) in regulating fear memory extinction, as well as fear coping mechanisms, in male and female rats
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