Navegando por Palavras-chave "Anhedonia"

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    Chronic mild stress induces widespread decreases in thyroid hormone alpha(1) receptor mRNA levels in brain-Reversal by imipramine
    (Elsevier B.V., 2009-02-01) Stein, Edward J.; Silveira Filho, Nylson Gomes da [UNIFESP]; Machado, Danilo C. [UNIFESP]; Hipolide, Debora C. [UNIFESP]; Barlow, Karen; Nobrega, Jose N.; Ctr Addict & Mental Hlth; Univ Toronto; Universidade Federal de São Paulo (UNIFESP)
    While considerable clinical evidence implicates thyroid hormones (THs) in depressive illness, the specific nature of this involvement remains unclear. the alpha(1) subtype (TR-alpha(1)) is the most abundant TH receptor in brain. Here we investigated changes in TR-alpha(1) mRNA in the chronic mild stress (CMS) model of depression. Rats were exposed to a CMS schedule for 3 weeks, which resulted in a progressive decreases in sucrose preference (an index of anhedonia). They were then treated daily with either imipramine (IMI, 10 mg/kg) or vehicle (VEH) for 2 weeks before being sacrificed for quantitative in situ hybridization analyses of TR-alpha(1) mRNA throughout the brain.Results indicated that CMS followed by VEH induced widespread decreases in TR-alpha(1) mRNA in brain. in contrast, CMS-exposed rats receiving IMI for the last 2 weeks prior to sacrifice showed full recovery of sucrose preference. Furthermore, brain TR-alpha(1) mRNA levels in these animals were similar to those of non-stressed controls receiving either SAL or IMI. These results reveal that TR-alpha(1) mRNA brain levels are very sensitive to CMS effects. the reversal of both anhedonic and TR-alpha(1) effects of CMS by IMI suggests that TR-alpha(1) may play a role both in stress-induced depressive symptoms and in their reversal by antidepressant interventions. (C) 2008 Elsevier B.V. All rights reserved.
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    Increased susceptibility to development of anhedonia in rats with chronic peripheral nerve injury: Involvement of sleep deprivation?
    (Elsevier B.V., 2009-08-31) Andersen, Monica L. [UNIFESP]; Hoshino, Katsumasa; Tufik, Sergio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Univ Estadual Paulista
    The Main purpose of the present study was to evaluate whether REM sleep deprivation (RSD) influences the development of anhedonia in rats in a peripheral neuropathy model induced by sciatic nerve constriction injury (CCI). Anhedonia was measured by assessing daily water/sucrose intake. Four groups were assessed: control (CTRL), CCI, RSD, and CCI + RSD (n = 8/group). Intake data were collected at baseline (mean of 3 days), on the 1st and 2nd days after a CCI or SHAM procedure, during 4 days of RSD, and during an additional 10 days (rebound period or equivalent in home-cage rats). Control rats spontaneously and progressively increased Sucrose intake, reaching final daily volumes significantly greater than respective initial baseline amounts. RSD promoted an additional and immediate significant increase in sucrose intake during sleep deprivation days. the CCI group did not display a spontaneous, progressive increase in sucrose intake. When CO was combined with RSD, the increase in sucrose intake induced by RSD was significantly lower than in animals submitted to RSD alone; the (CCI + RSD) group also failed to show a spontaneous and progressive increase in sucrose intake. the present findings indicate that animal model of chronic neuropathy exhibits reduced sucrose ingestion. Accordingly, this anhedonic condition that constitutes to the core manifestation of depressive states did not occur in response to a single episode of total RSD. (C) 2009 Elsevier Inc. All rights reserved.
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    Multiple trial inhibitory avoidance acquisition and retrieval are resistant to chronic stress
    (Elsevier Science Bv, 2018) Raya, J. [UNIFESP]; Girardi, C. E. N. [UNIFESP]; Esumi, L. A. [UNIFESP]; Ferreira, L. B. T. [UNIFESP]; Hipolide, D. C. [UNIFESP]
    Chronic mild stress (CMS) is a widely accepted animal model relevant to depression that among other consequences, is chiefly known to induce anhedonia, often assessed as decreased preference for sucrose solution. CMS is also known to affect cognition, particularly memory tasks. In this study we have employed the multiple trial inhibitory avoidance memory task (MTIA) to assess CMS effects on memory acquisition and retrieval. MTIA consists of repeated exposures to the unconditioned stimulus until a learning criterion is reached. Wistar rats underwent CMS for 5 weeks, and sucrose consumption was assessed once a week. At the end of CMS, animals were evaluated in the MTIA task. Overall decreased sucrose solution preference was highly variable. Further analyses showed that a subset of animals expressed resilience while another subset was sensitive to stress. CMS did not affect the number of acquisition sessions before reaching criterion or retrieval latency of MTIA task in neither sensitive nor resilient groups. Although tasks that assess learning ability in animal models relevant to depression indicate cognitive deficits, the ability to learn the association between compartment crossing and the aversive electric foot shock, which is strongly dependent on emotional aspects, was intact.
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    Neonatal exposure to constant light prevents anhedonia-like behavior induced by constant light exposure in adulthood
    (Elsevier B.V., 2011-09-12) Martynhak, Bruno J.; Correia, Diego; Morais, Livia H.; Araujo, Paula [UNIFESP]; Andersen, Monica L. [UNIFESP]; Lima, Marcelo M. S.; Louzada, Fernando M.; Andreatini, Roberto; Univ Fed Parana; Universidade Federal de São Paulo (UNIFESP)
    Depressive episodes are associated with disturbances in circadian rhythms, and constant illumination has been reported to induce depressive-like behavior in rodents. Rats kept in constant darkness express the endogenous circadian rhythm, and most animals under constant light conditions lose circadian locomotor rhythmicity. Exposure to constant light in rats during lactation was reported to prevent this loss of circadian rhythm in adulthood. Thus, the aim of the present study was to verify whether exposure to constant light during lactation prevents anhedonia-like behavior induced by constant light in adult rats. in experiment 1, we replicated the anhedonia-like effects of constant light in adult male rats. We showed that this effect is reversed by imipramine treatment in the drinking water. in experiment 2, we subjected rats to constant darkness (neonatal-DD), constant light (neonatal-LL) or to normal light/dark cycle (neonatal-LD) during the neonatal phase and evaluated them after constant light exposure in adulthood. the group exposed to constant light during the neonatal phase did not reduce their sucrose preference and exhibited greater locomotor activity than the other groups. the neonatal-DD group exhibited decreased sucrose preference earlier than controls and had higher serum corticosterone concentrations. Prevention of arrhythymicity might protect neonatal-LL rats from anhedonia-like behavior induced by constant light, whereas constant darkness during the neonatal phase rendered the neonatal-DD group more susceptible to depressive-like behavior. These results corroborate with the literature data indicating that circadian disruption may contribute in mood disorders and that early life stress can influence stress responsivity in adulthood. (C) 2011 Elsevier B.V. All rights reserved.
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    Withdrawal from repeated treatment with ethanol induces a protracted decrease in novelty-seeking behavior and enhancement of environmental habituation in mice
    (Elsevier B.V., 2012-03-01) Fukushiro, Daniela F. [UNIFESP]; Saito, Luis P. [UNIFESP]; Mari-Kawamoto, Elisa [UNIFESP]; Aramini, Tatiana C. F. [UNIFESP]; Costa, Jacqueline M. [UNIFESP]; Josino, Fabiana S. [UNIFESP]; Uehara, Regina A. [UNIFESP]; Frussa-Filho, Roberto [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Ethanol withdrawal syndrome is characterized by somatic and behavioral symptoms, including increased anxiety and anhedonia. in animal models, however, there are many studies on the anxiogenic effects occurring during the first 24 h after ethanol withdrawal, while anhedonia has been overlooked. Recently, we have found that amphetamine withdrawal reduced novelty seeking and enhanced environmental habituation in mice, two motivation-related behaviors. We now investigate the effects of withdrawal from ethanol, a drug of abuse with a different pharmacological profile, on these two motivation-related behaviors. Swiss male mice (3 months old) were treated with 1.8 g/kg ethanol for 21 consecutive days in their home cages. Seven days after ethanol withdrawal, mice were tested in a free-choice novelty apparatus containing one familiar and one novel compartment. Novelty-seeking behavior was assessed by comparing time spent in the novel compartment versus the familiar compartment, whereas environmental habituation was concomitantly evaluated by the time-response curve of total locomotion (novel + familiar). Novelty seeking was decreased and environmental habituation was enhanced during ethanol withdrawal. These anhedonic responses were not associated with concurrent changes in the anxiety-like behavior of mice (as confirmed in the elevated plus-maze test). We propose that the concomitant evaluation of novelty-seeking behavior and environmental habituation can be useful to study the behavioral consequences not only of amphetamine withdrawal but also of ethanol withdrawal. Furthermore, the present data support recent clinical findings that suggest the occurrence of protracted anhedonia well beyond the limited period immediately following the abrupt cessation of ethanol intake. (C) 2012 Elsevier Inc. All rights reserved.