Social-single prolonged stress as an ether-free candidate animal model of post-traumatic stress disorder: Female and male outcomings.

BACKGROUND: Single Prolonged Stress (SPS) is a valid animal model that reflects the core of post-traumatic stress disorder (PTSD) phenotypes. Although SPS has been a pivotal tool, it can bring ethics approval difficulties due to the use of ether as a stressor. The present study evaluated if changing a chemical (ether) with a social stressor resembles the PTSD hallmark symptoms. METHODS: Female and male young adult rats were distributed in Sham and Social-SPS groups. Rats in Social-SPS groups were subjected to stress, whereas those in Sham groups remained undisturbed. One set of animals performed the behavioral tests, elevated plus-maze (EPM) and Y-maze. Plasma corticosterone levels and cortical and hippocampal molecular protein contents were analyzed. Another set of animals performed the dexamethasone suppression test. RESULTS: A significant decrease in the percentage of time spent and the number of entries in open arms and an increase in anxiety index in the EPM were observed in rats of the social-SPS groups. In the Social-SPS groups, rats reduced the spontaneous alternations in Y-maze. The Social-SPS exposure enhanced the HPA-axis feedback and increased glucocorticoid receptor contents in the cerebral cortex and hippocampus of rats. A decrease in the content of synaptic integrity-related proteins, synaptophysin, and PSD-95, were found in the cortex and hippocampus of rats subjected to social-SPS. There were no statistical differences between males and females in any parameter analyzed. LIMITATIONS: The absence of a task to recap criterion E 'arousal' and predictive validity experiments. CONCLUSIONS: This study reveals that social-SPS recapitulated the main clusters required for a candidate animal model of PTSD.

Contribution of Opioid and Nitrergic Systems to m-Trifluoromethyl diphenyl Diselenide Attenuates Morphine-Induced Tolerance in Mice.

m-Trifluoromethyl diphenyl diselenide (TFDD) has antinociceptive and antidepressant-like properties and attenuates morphine withdrawal signs in mice. This study investigated if TFDD affects the development of morphine tolerance to its antinociceptive and antidepressant-like effects in mice. We also investigated whether TFDD modulates signaling pathways related to morphine tolerance, including the opioid receptors and some parameters of the nitrergic system. Male adult Swiss mice received morphine alone (5 mg/kg, subcutaneous) and in combination with TFDD (10 mg/kg, intragastric) for 7 days. Mice were subjected to hot plate and forced swim tests on days 1, 3, 5, and 7 of the experimental protocol. Repeated TFDD administrations avoided tolerance development mediated by morphine, including its antinociceptive and antidepressant-like effects. A single morphine dose increased MOR and NOx but decreased iNOS contents in the mouse cerebral cortex. In turn, single morphine and TFDD co-administration restored the MOR and iNOS protein levels. On the other hand, morphine repeated doses enhanced DOR and reduced MOR and NOx contents, whereas the morphine and TFDD association reestablished DOR and NOx levels in the mouse cerebral cortex. In conclusion, some opioid and nitrergic system parameters might contribute to TFDD attenuation of antinociceptive and antidepressant-like tolerance induced by morphine in mice.

m-CF3-substituted diphenyl diselenide attenuates all phases of morphine-induced behavioral locomotor sensitization in mice.

BACKGROUND: Behavioral sensitization, thought to underlie some aspects of drug dependence, is typically measured as increased locomotion in response to repeated administration of a drug. The study aimed to investigate the (m-CF3-PhSe)2 effects on the acquisition, withdrawal, and re-exposure phases of morphine-induced behavioral locomotor sensitization. METHODS: Swiss male mice were treated with saline or morphine at 10 mg/kg twice a day for 3 days; those of the morphine group were kept in the morphine withdrawal period (5 days). On day 9, mice were re-exposed to morphine. (m-CF3-PhSe)2 (10 mg/kg) or vehicle was administered at all phases of morphine protocol, and mice performed locomotor activity test. Oxidative stress markers and the levels of opioid, dopamine, and glutamate receptors were determined in samples of the cerebral cortex. (m-CF3-PhSe)2 administered at all phases of protocol attenuated morphine-induced locomotor sensitization. RESULTS: Mice exposed to morphine showed reduced weight gain and increased locomotor activity, but (m-CF3-PhSe)2 treatment attenuates the weight gain and behavioral hyperlocomotion effects. (m-CF3-PhSe)2, independent of the administration phase, modulated the increase of opioidergic (MOR, DOR, KOR) and glutamatergic (NMDA 2A and 2B) protein contents and attenuated redox imbalance in the cerebral cortex of mice exposed to morphine. However, (m-CF3-PhSe)2 did not modulate cortical protein levels of dopaminergic (D1 and D2) receptors in the acquisition phase of morphine-induced locomotor sensitization protocol. CONCLUSION: (m-CF3-PhSe)2 was effective against the behavioral and molecular alterations caused by morphine at all phases of locomotor sensitization.

CF3-substituted diselenide modulatory effects on oxidative stress, induced by single and repeated morphine administrations, in susceptible tissues of mice.

Studies reveal that oxidative stress is associated with adverse effects of long-term morphine treatment. The m-trifluoromethyl-diphenyl diselenide (CF3) is a multi-target organoselenium compound that has antioxidant properties in different experimental models. This study aimed to investigate the CF3 effects against redox imbalance in peripheral and central tissues of mice, after single or multiple morphine doses. Swiss male mice received a single dose of morphine (5 mg/kg, s.c.) and CF3 (10 mg/kg, i.g.), or morphine was repeatedly injected (5 mg/kg, s.c.) and CF3 (10 mg/kg, i.g.) administered twice daily for 7 days. Oxidative stress was determined in the hippocampus, liver, and kidney. CF3 reversed the increase in reactive species caused by single and multiple morphine doses in the peripheral tissues. CF3 increased hepatic non-protein thiol levels and the superoxide dismutase (SOD) activity decreased by a single morphine dose. CF3 reversed the reduction in SOD activity in the kidney of mice repeatedly exposed to morphine. The study demonstrates that peripheral tissues were more susceptible than the hippocampus to oxidative stress induced by morphine in mice. The results show that CF3 modulated parameters of oxidative stress modified by single and multiple morphine administrations in peripheral and central tissues of mice.

Parasitóides de dípteros muscóides coletados no matadouro Alvorada em Itumbiara, sul de Goiás, Brasil / Parasitoids of muscoids diptera collected at Alvorada slaughterhouse in Itumbiara, south of Goiás, Brazil

Espécies de parasitóides associados com moscas sinantrópicas foram coletadas com auxílio de iscas de fígado bovino no matadouro Alvorada em Itumbiara, Estado de Goiás, de março a dezembro de 2005. As pupas foram removidas da areia, após usar iscas de fígado como substrato para atrair as moscas. Elas foram individualizadas em cápsulas de gelatina até a emergência dos adultos de moscas ou de seus parasitóides. A prevalência total de parasitismo foi 15,3 por cento. A freqüência absoluta, porcentagem e espécies de parasitóides coletados foram: 205 exemplares (2,3 por cento) de Aphaereta sp., 173 (80,0 por cento) de Brachymeria podagrica, 578 (15,7 por cento) Nasonia vitripennis, um (0,5 por cento) de Pachycrepoideus vindemmiae, dois (0,9 por cento) de Spalangia sp. e um (0,5 por cento) de Trybliographa sp. A porcentagem de parasitismo apresentada pelos parasitóides de Aphaereta sp., B. podagrica, N. vitripennis, P. vindemmiae, Spalangia sp., e Trybliographa sp. foi de 0,4 por cento, 12,3 por cento, 2,4 por cento, 0,1 por cento, 0,1 por cento e 0,1 por cento, respectivamente. As espécies de dípteros parasitados foram: Chrysomya albiceps, C. megacephala, Musca domestica, Oxysarcodexia thornax, Peckia chrysostoma e Sarcodexia lambens.

Species of parasitoids associated with synanthropic flies were trapped by using shopped bovine liver as bites at slaughterhouse Itumbiara in the State of Goiás, from March to December 2005. Pupae were obtained by removing them from sand, after using liver baits as substract to atract flies. They were individually placed in gelatin capsules until the emergency of the adult flies or their parasitoids. The overall prevalence of parasitism was 15.3 percent. The frequency, percentage and species of parasitoids collected were: 205 specimens (2.3 percent) of Aphaereta sp., 173 (80.0 percent) of Brachymeria podagrica, 578 (15.7 percent) of Nasonia vitripennis, one (0.5 percent) of Pachycrepoideus vindemmiae and two (0.9 percent) of Spalangia sp. and one (0.5 percent) of Trybliographa sp., respectively. The parasitoids Aphaereta sp., B. podagrica, N. vitripennis, P. vindemmiae, Spalangia sp. and Trybliographa sp. had a parasitism percentage of 0.4, 12.3, 2.4, 0.1, 0.1 and 0.1, respectively. The parasitizing diptera were: Chrysomya albiceps, C . megacephala, Musca domestica, Oxysarcodexia thornax, Peckia chrysostoma and Sarcodexia lambens.

[Parasitoids of muscoids diptera collected at Alvorada slaughterhouse in Itumbiara, south of Goiás, Brazil]. / Parasitóides de dípteros muscóides coletados no matadouro Alvorada em Itumbiara, sul de Goaiás, Brasil.

Species of parasitoids associated with synanthropic flies were trapped by using chopped bovine liver as bites at slaughterhouse Itumbiara in the State of Goiás, from March to December 2005. Pupae were obtained by removing them from sand, after using liver baits as substract to atract flies. They were individually placed in gelatin capsules until the emergency of the adult flies or their parasitoids. The overall prevalence of parasitism was 15.3%. The frequency, percentage and species of parasitoids collected were: 205 specimens (2.3%) of Aphaereta sp., 173 (80.0%) of Brachymeria podagrica, 578 (15.7%) of Nasonia vitripennis, one (0.5%) of Pachycrepoideus vindemmiae and two (0.9%) of Spalangia sp. and one (0.5%) of Trybliographa sp., respectively. The parasitoids Aphaereta sp., B. podagrica, N. vitripennis, P. vindemmiae, Spalangia sp. and Trybliographa sp. had a parasitism percentage of 0.4, 12.3, 2.4, 0.1, 0.1 and 0.1, respectively. The parasitizing diptera were: Chrysomya albiceps, C . megacephala, Musca domestica, Oxysarcodexia thornax, Peckia chrysostoma and Sarcodexia lambens.