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1.
PLoS Biol ; 21(11): e3002396, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38033154

RESUMO

A study in PLOS Biology by Rojek-Sito and colleagues demonstrates a key role of the central amygdala and specific circuits projecting to and from this brain area in the initiation versus maintenance of positive social interactions.


Assuntos
Tonsila do Cerebelo , Interação Social , Ratos , Animais , Tonsila do Cerebelo/fisiologia , Optogenética , Neurônios/fisiologia , Encéfalo/fisiologia
2.
Nature ; 621(7980): 693-694, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37735608

Assuntos
Animais , Camundongos
3.
Rev Esp Enferm Dig ; 112(11): 821-825, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33054301

RESUMO

INTRODUCTION: endoscopy plays an essential role in the management of patients with ulcerative colitis (UC), as it allows us to visualize and assess the severity of the disease. Different scores have been devised to standardize the findings because such assessments are not always objective. AIMS: the aim of this study was to assess the interobserver variability between the Index of Mayo Endoscopy (IME) and the Ulcerative Colitis Endoscopy Index of Severity (UCEIS), analyzing the severity of the endoscopic lesions in patients with UC. The secondary aim was to analyze if the cathartic preparation affected the degree of concordance amongst the endoscopists. MATERIAL AND METHODS: this was a single-cohort observational, comparative study in which a colonoscopy was performed in patients with UC, as the normal clinical practice. The results were classified according to the IME and the UCEIS by three endoscopic specialists. In order to assess the degree of interobserver correlation, the Kappa index for IME was used and the intraclass correlation coefficient was used for UCEIS. RESULTS: sixty-seven patients were included in the study. The average age was 51 (SD ± 16.7) and the average Mayo Clinic index was 3.07 (SD ± 2.54). The weighted Kappa index between endoscopists A and B for the IME was 0.8, 0.52 between A and C and 0.49 between B and C. The intraclass correlation coefficient for UCEIS was 0.922 between the three endoscopists (95 % CI: 0.832-0.959). A better interobserver correlation was found when the cathartic preparation was ≥ 8 based on the Boston Scale. CONCLUSIONS: there was a higher correlation between the different endoscopists for the UCEIS than for the IME. Thus, this should be considered to be the best index to use in the clinical practice. A good cleansing preparation is important to improve the interobserver correlation.


Assuntos
Colite Ulcerativa , Estudos de Coortes , Colite Ulcerativa/diagnóstico , Colonoscopia , Humanos , Pessoa de Meia-Idade , Variações Dependentes do Observador , Índice de Gravidade de Doença
5.
Rev Esp Enferm Dig ; 109(8): 552-558, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28617030

RESUMO

OBJECTIVE: To evaluate the efficacy and safety of a quadruple regimen (BMTO) of the "3-in-1 capsule" (containing bismuth subcitrate potassium, metronidazole and tetracycline) plus omeprazole in naïve and previously treated patients diagnosed with Helicobacter pylori (H. pylori) infection in the clinical setting in Seville (Spain). METHODS: This is a prospective study carried out on consecutive patients with a confirmed H. pylori infection and upper gastrointestinal symptoms. After providing their informed consent, the patients were treated for ten days with a 3-in-1 capsule containing bismuth subcitrate potassium (140 mg), metronidazole (125 mg) and tetracycline (125 mg: Pylera®), three capsules four times daily, plus omeprazole (20 or 40 mg) twice daily. Eradication of infection was determined by a negative urea breath test at least 28 days after the end of treatment. RESULTS: A total of 58 consecutive patients were enrolled into this study, two of whom withdrew early due to vomiting on days three and five, respectively. In this cohort, 17 patients (29.3%) had a prior history of medication to treat H. pylori. In the intent-to-treat population, eradication was achieved in 97.6% (40/41) and 82.4% (14/17) of cases in patients treated with BMTO as a first-line or rescue therapy, respectively. At least one adverse event was reported by 28 (48%) patients, mostly mild effects (86%). CONCLUSION: A ten day treatment with BMTO is an effective and safe strategy to combat confirmed H. pylori infection in patients.


Assuntos
Antibacterianos/uso terapêutico , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori , Metronidazol/uso terapêutico , Omeprazol/uso terapêutico , Compostos Organometálicos/uso terapêutico , Inibidores da Bomba de Prótons/uso terapêutico , Tetraciclina/uso terapêutico , Adulto , Idoso , Antibacterianos/efeitos adversos , Estudos de Coortes , Combinação de Medicamentos , Quimioterapia Combinada , Feminino , Humanos , Masculino , Metronidazol/efeitos adversos , Pessoa de Meia-Idade , Omeprazol/administração & dosagem , Compostos Organometálicos/efeitos adversos , Estudos Prospectivos , Inibidores da Bomba de Prótons/administração & dosagem , Tetraciclina/efeitos adversos , Resultado do Tratamento
6.
Breast Cancer Res ; 16(4): R76, 2014 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-25186428

RESUMO

INTRODUCTION: Human epidermal growth factor receptor 2 (HER2) amplification is frequent in ductal carcinoma in situ (DCIS) of the breast and is associated with poorly differentiated tumors and adverse prognosis features. This study aimed to determine the molecular effects of the HER2 inhibitor lapatinib in patients with HER2 positive DCIS. METHODS: Patients with HER2 positive DCIS received 1,500 mg daily of lapatinib for four consecutive weeks prior to surgical resection. Magnetic resonance imaging (MRI) was used to determine changes in tumor volume. The molecular effects of lapatinib on HER2 signaling (PI3K/AKT and RAS/MAPK pathways), cell proliferation (Ki67 and p27) and apoptosis (TUNEL) were determined in pre and post-lapatinib treatment samples. RESULTS: A total of 20 patients were included. Lapatinib was well tolerated with only minor and transient side effects. The agent effectively modulated HER2 signaling decreasing significantly pHER2 and pERK1 expression, together with a decrease in tumor size evaluated by MRI. There was no evidence of changes in Ki67. CONCLUSIONS: Four weeks of neoadjuvant lapatinib in patients with HER2-positive DCIS resulted in inhibition of HER2 and RAS/MAPK signaling pathway. TRIAL REGISTRATION: 2008-004492-21 (Registered June 25th 2008).


Assuntos
Neoplasias da Mama/tratamento farmacológico , Carcinoma Intraductal não Infiltrante/tratamento farmacológico , Quinazolinas/administração & dosagem , Receptor ErbB-2/genética , Adulto , Idoso , Apoptose/efeitos dos fármacos , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinoma Intraductal não Infiltrante/genética , Carcinoma Intraductal não Infiltrante/patologia , Proliferação de Células/efeitos dos fármacos , Receptores ErbB/biossíntese , Receptores ErbB/genética , Feminino , Amplificação de Genes/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Hibridização in Situ Fluorescente , Lapatinib , Pessoa de Meia-Idade , Quinases de Proteína Quinase Ativadas por Mitógeno/efeitos dos fármacos , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Prognóstico , Quinazolinas/efeitos adversos , Receptor ErbB-2/biossíntese , Transdução de Sinais/efeitos dos fármacos
7.
Neurosci Biobehav Rev ; 163: 105776, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38909642

RESUMO

Prosocial behaviors (i.e., actions that benefit others) are central for social interactions in humans and other animals, by fostering social bonding and cohesion. To study prosociality in rodents, scientists have developed behavioral paradigms where animals can display actions that benefit conspecifics in distress or need. These paradigms have provided insights into the role of social interactions and transfer of emotional states in the expression of prosociality, and increased knowledge of its neural bases. However, prosociality levels are variable: not all tested animals are prosocial. Such variation has been linked to differences in animals' ability to process another's state as well as to contextual factors. Moreover, evidence suggests that prosocial behaviors involve the orchestrated activity of multiple brain regions and neuromodulators. This review aims to synthesize findings across paradigms both at the level of behavior and neural mechanisms. Growing evidence confirms that these processes can be studied in rodents, and intense research in the past years is rapidly advancing our knowledge. We discuss a strong bias in the field towards the study of these processes in negative valence contexts (e.g., pain, fear, stress), which should be taken as an opportunity to open new venues for future research.


Assuntos
Comportamento Animal , Roedores , Comportamento Social , Animais , Comportamento Animal/fisiologia , Encéfalo/fisiologia , Emoções/fisiologia , Humanos
8.
Curr Biol ; 32(15): 3288-3301.e8, 2022 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-35803272

RESUMO

Animals often display prosocial behaviors, performing actions that benefit others. Although prosociality is essential for social bonding and cooperation, we still know little about how animals integrate behavioral cues from those in need to make decisions that increase their well-being. To address this question, we used a two-choice task where rats can provide rewards to a conspecific in the absence of self-benefit and investigated which conditions promote prosociality by manipulating the social context of the interacting animals. Although sex or degree of familiarity did not affect prosocial choices in rats, social hierarchy revealed to be a potent modulator, with dominant decision-makers showing faster emergence and higher levels of prosocial choices toward their submissive cage mates. Leveraging quantitative analysis of multimodal social dynamics prior to choice, we identified that pairs with dominant decision-makers exhibited more proximal interactions. Interestingly, these closer interactions were driven by submissive animals that modulated their position and movement following their dominants and whose 50-kHz vocalization rate correlated with dominants' prosociality. Moreover, Granger causality revealed stronger bidirectional influences in pairs with dominant focals and submissive recipients, indicating increased behavioral coordination. Finally, multivariate analysis highlighted body language as the main information dominants use on a trial-by-trial basis to learn that their actions have effects on others. Our results provide a refined understanding of the behavioral dynamics that rats use for action-selection upon perception of socially relevant cues and navigate social decision-making.


Assuntos
Sinais (Psicologia) , Comportamento Social , Altruísmo , Animais , Hierarquia Social , Ratos , Recompensa
9.
Elife ; 112022 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-35043782

RESUMO

Laboratory behavioural tasks are an essential research tool. As questions asked of behaviour and brain activity become more sophisticated, the ability to specify and run richly structured tasks becomes more important. An increasing focus on reproducibility also necessitates accurate communication of task logic to other researchers. To these ends, we developed pyControl, a system of open-source hardware and software for controlling behavioural experiments comprising a simple yet flexible Python-based syntax for specifying tasks as extended state machines, hardware modules for building behavioural setups, and a graphical user interface designed for efficiently running high-throughput experiments on many setups in parallel, all with extensive online documentation. These tools make it quicker, easier, and cheaper to implement rich behavioural tasks at scale. As important, pyControl facilitates communication and reproducibility of behavioural experiments through a highly readable task definition syntax and self-documenting features. Here, we outline the system's design and rationale, present validation experiments characterising system performance, and demonstrate example applications in freely moving and head-fixed mouse behaviour.


Assuntos
Ciências do Comportamento/métodos , Animais , Computadores , Camundongos , Reprodutibilidade dos Testes , Software
10.
Gastroenterol Hepatol ; 34(4): 262-5, 2011 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-21477889

RESUMO

Acute porphyria is a term that encompasses a group of hereditary disorders involving defects in heme metabolism, characterized by acute episodes of abdominal pain, acute hypertension, tachycardia and neuropsychiatric disorders, sometimes leading to convulsions, ascending paralysis and coma. Misdiagnosis or delayed diagnosis can seriously worsen prognosis. We report the case of a woman with subclinical acute intermittent porphyria and chronic hepatitis incidentally diagnosed due to transaminase elevation on laboratory analysis.


Assuntos
Hepatite/etiologia , Adulto , Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Biópsia , Doença Crônica , Diagnóstico Diferencial , Eritrócitos/enzimologia , Feminino , Genes Dominantes , Hepatite/sangue , Hepatite/patologia , Hepatite Autoimune/diagnóstico , Humanos , Hidroximetilbilano Sintase/sangue , Achados Incidentais , Penetrância , Porfiria Aguda Intermitente/complicações , Porfiria Aguda Intermitente/diagnóstico , Porfiria Aguda Intermitente/genética , Porfiria Aguda Intermitente/metabolismo
11.
Sci Rep ; 11(1): 14599, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34272430

RESUMO

Social hierarchy is a potent modulator of behavior, that is typically established through overt agonistic interactions between individuals in the group. Once established, social ranks are maintained through subtler interactions allowing the redirection of energy away from agonistic interactions towards other needs. The available tasks for assessing social rank in rats allow the study of the mechanisms by which social hierarches are formed in early phases but fail to assess the maintenance of established hierarchies between stable pairs of animals, which might rely on distinct neurobiological mechanisms. Here we present and validate a novel trial-based dominancy assay, the modified Food Competition test, where established social hierarchies can be identified in the home cage of non-food deprived pairs of male rats. In this task, we introduce a small conflict in the home cage, where access to a new feeder containing palatable pellets can only be gained by one animal at a time. We found that this subtle conflict triggered asymmetric social interactions and resulted in higher consumption of food by one of the animals in the pair, which reliably predicted hierarchy in other tests. Our findings reveal stable dominance status in pair-housed rats and provide a novel tool for the evaluation of established social hierarchies, the modified Food Competition test, that is robust and easy to implement.


Assuntos
Comportamento Animal , Comportamento Competitivo , Hierarquia Social , Predomínio Social , Animais , Comportamento Alimentar , Alimentos , Masculino , Ratos , Ratos Sprague-Dawley , Recompensa
12.
PLoS One ; 16(3): e0247996, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33690698

RESUMO

We present a novel metric for measuring relative connection between parts of a city using geotagged Twitter data as a proxy for co-occurrence of city residents. We find that socioeconomic similarity is a significant predictor of this connectivity metric, which we call "linkage strength": neighborhoods that are similar to one another in terms of residents' median income, education level, and (to a lesser extent) immigration history are more strongly connected in terms of the of people who spend time there, indicating some level of homophily in the way that individuals choose to move throughout a city's districts.


Assuntos
Rede Social , Cidades , Escolaridade , Emigração e Imigração , Humanos , Renda , Características de Residência , Mídias Sociais , Suécia
13.
Endosc Int Open ; 9(2): E130-E136, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33532549

RESUMO

Background and study aims: Endoscopy plays an essential role in managing patients with ulcerative colitis (UC), as it allows us to visualize and assess the severity of the disease. As such assessments are not always objective, different scores have been devised to standardize the findings. The main aim of this study was to assess the interobserver variability between the Mayo Endoscopy Score (MES), Ulcerative Colitis Endoscopy Index of Severity (UCEIS) and Ulcerative Colitis Colonoscopy Index of Severity (UCCIS) analyzing the severity of the endoscopic lesions in patients with ulcerative colitis. Patients and methods: This was a single-cohort observational study in which a colonoscopy was carried out on patients with UC, as normal clinical practice, and a video was recorded. The results from the video were classified according to the MES, UCEIS and UCCIS by three endoscopic specialists independently, and they were compared to each other. The Mayo Endoscopy Score (MES) was used to assess the clinical situation of the patient. The therapeutic impact was analyzed after colonoscopy was carried out. Results: Sixty-seven patients were included in the study. The average age was 51 (SD ±â€Š16.7) and the average MES was 3.07 (SD ±â€Š2.54). The weighted Kappa index between endoscopists A and B for the MES was 0.8; between A and C 0.52; and between B and C 0.49. The intraclass correlation coefficient for UCEIS was 0.92 among the three endoscopists (CI 95 %: 0.83-0.96) and 0.96 for UCCIS among the three endoscopists (CI 95 % 0.94-0.97). A change in treatment for 34.3 % of the patients was implemented on seeing the results of the colonoscopy. Conclusions: There was an adequate, but not perfect, correlation between the different endoscopists for MES, UCEIS, UCCIS. This was higher with the last two scores. Thus, there is still some subjectivity to be minimized through special training, on assessing the seriousness of the endoscopic lesions in patients with UC.

14.
Curr Biol ; 30(6): 1128-1135.e6, 2020 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-32032509

RESUMO

Social cues of threat are widely reported [1-3], whether actively produced to trigger responses in others such as alarm calls or by-products of an encounter with a predator, like the defensive behaviors themselves such as escape flights [4-14]. Although the recognition of social alarm cues is often innate [15-17], in some instances it requires experience to trigger defensive responses [4, 7]. One mechanism proposed for how learning from self-experience contributes to social behavior is that of auto-conditioning, whereby subjects learn to associate their own behaviors with relevant trigger events. Through this process, the same behaviors, now displayed by others, gain meaning [18, 19] (but see [20]). Although it has been shown that only animals with prior experience with shock display observational freezing [21-25], suggesting that auto-conditioning could mediate this process, evidence for this hypothesis was lacking. Previously we found that, when a rat freezes, the silence that results from immobility triggers observational freezing in its cage-mate, provided the cage-mate had experienced shocks before [24]. Therefore, in our study, auto-conditioning would correspond to rats learning to associate shock with their own response to it-freezing. Using a combination of behavioral and optogenetic manipulations, here, we show that freezing becomes an alarm cue by a direct association with shock. Our work shows that auto-conditioning can indeed modulate social interactions, expanding the repertoire of cues mediating social information exchange, providing a framework to study how the neural circuits involved in the self-experience of defensive behaviors overlap with the ones involved in socially triggered defensive behaviors.


Assuntos
Condicionamento Psicológico , Sinais (Psicologia) , Reação de Congelamento Cataléptica , Aprendizagem , Ratos/psicologia , Animais , Acontecimentos que Mudam a Vida , Masculino , Ratos Sprague-Dawley
15.
Psychoneuroendocrinology ; 33(4): 437-45, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18276081

RESUMO

Several studies performed in outbred Roman high- and low-avoidance lines (RHA and RLA, respectively) have demonstrated that the more anxious line (RLA) is characterized by a higher hypothalamic-pituitary-adrenal (HPA) response to certain stressors than the less anxious one (RHA). However, inconsistent results have also been reported. Taking advantage of the generation of an inbred colony of RLA and RHA rats (RHA-I and RLA-I, respectively), we have characterized in the two strains not only resting and stress levels of peripheral HPA hormones but also central components of the HPA axis, including CRF gene expression in extra-hypothalamic areas. Whereas resting levels of ACTH and corticosterone did not differ between the strains, a greater response to a novel environment was found in RLA-I as compared to RHA-I rats. RLA-I rats showed enhanced CRF gene expression in the paraventricular nucleus (PVN) of the hypothalamus, with normal arginin-vasopressin gene expression in both parvocellular and magnocellular regions of the PVN. This enhanced CRF gene expression is not apparently related to altered negative corticosteroid feedback as similar levels of expression of brain glucorticoid and mineralocorticoid receptors were found in the two rat strains. CRF gene expression tended to be higher in the central amygdala and it was significantly higher in the dorsal region of the bed nucleus of stria terminalis (BNST) of RLA-I rats, while no differences appeared in the ventral region of BNST. Considering the involvement of CRF and the BNST in anxiety and stress-related behavioral alterations, the present data suggest that the CRF system may be a critical neurobiological substrate underlying differences between the two rat strains.


Assuntos
Ansiedade/metabolismo , Hormônio Liberador da Corticotropina/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Estresse Psicológico/metabolismo , Hormônio Adrenocorticotrópico/sangue , Tonsila do Cerebelo/metabolismo , Análise de Variância , Animais , Ansiedade/complicações , Ansiedade/genética , Arginina Vasopressina/genética , Arginina Vasopressina/metabolismo , Corticosterona/sangue , Hormônio Liberador da Corticotropina/genética , Masculino , Núcleo Hipotalâmico Paraventricular/metabolismo , RNA Mensageiro/análise , Ratos , Ratos Endogâmicos , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Receptores de Mineralocorticoides/genética , Receptores de Mineralocorticoides/metabolismo , Seleção Genética , Núcleos Septais/metabolismo , Especificidade da Espécie , Estresse Psicológico/complicações , Estresse Psicológico/genética
16.
Talanta ; 161: 80-86, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27769485

RESUMO

Two data fusion strategies (high- and mid-level) combined with a multivariate classification approach (Soft Independent Modelling of Class Analogy, SIMCA) have been applied to take advantage of the synergistic effect of the information obtained from two spectroscopic techniques: FT-Raman and NIR. Mid-level data fusion consists of merging some of the previous selected variables from the spectra obtained from each spectroscopic technique and then applying the classification technique. High-level data fusion combines the SIMCA classification results obtained individually from each spectroscopic technique. Of the possible ways to make the necessary combinations, we decided to use fuzzy aggregation connective operators. As a case study, we considered the possible adulteration of hazelnut paste with almond. Using the two-class SIMCA approach, class 1 consisted of unadulterated hazelnut samples and class 2 of samples adulterated with almond. Models performance was also studied with samples adulterated with chickpea. The results show that data fusion is an effective strategy since the performance parameters are better than the individual ones: sensitivity and specificity values between 75% and 100% for the individual techniques and between 96-100% and 88-100% for the mid- and high-level data fusion strategies, respectively.


Assuntos
Cicer , Corylus , Contaminação de Alimentos/análise , Preparações de Plantas/análise , Prunus dulcis , Análise Multivariada , Nozes , Espectroscopia de Luz Próxima ao Infravermelho , Análise Espectral Raman
17.
Psychoneuroendocrinology ; 30(2): 179-87, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15471615

RESUMO

Susceptibility to some stress-induced pathologies may be strongly related to individual differences in the responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis to stressors. However, there have been few attempts in rodents to study the reliability of the individual differences in the responsiveness of the HPA to stressors and the relationship to resting corticosterone levels. In the present work, we used a normal population of Sprague-Dawley rats, with a within-subject design. Our objectives were to study: (a) the reliability of the ACTH and corticosterone response to three different novel environments widely used in psychopharmacology and (b) the relationship between stress levels of HPA hormones and the daily pattern of corticosterone secretion (six samples over a 24-h-period). Animals were repeatedly sampled using tail-nick procedure. The novel environments were the elevated plus-maze, the hole-board and the circular corridor. Animals were sampled just after 15 min exposure to the tests and again at 15 and 30 min after the termination of exposure to them (post-tests). The hormonal levels just after the tests indicate that the hole-board seems to be more stressful than the circular corridor and the elevated plus-maze, the latter being characterized by the lowest defecation rate. Correlational analysis revealed that daily pattern of resting plasma corticosterone levels did not correlate to HPA responsiveness to the tests, suggesting no relationship between resting and stress levels of HPA hormones. In contrast, the present study demonstrates, for the first time, a good within-subject reliability of the ACTH and corticosterone responses to the three environments, suggesting that HPA responsiveness to these kind of stressors is a consistent individual trait in adult rats, despite differences in the physical characteristics of the novel environments.


Assuntos
Comportamento Exploratório/fisiologia , Sistema Hipotálamo-Hipofisário/fisiologia , Individualidade , Sistema Hipófise-Suprarrenal/fisiologia , Estresse Psicológico/sangue , Hormônio Adrenocorticotrópico/sangue , Análise de Variância , Animais , Área Sob a Curva , Corticosterona/sangue , Meio Ambiente , Masculino , Personalidade/fisiologia , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes
18.
Curr Biol ; 25(13): 1736-45, 2015 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-26051895

RESUMO

Animals often are prosocial, displaying behaviors that result in a benefit to one another [1-15] even in the absence of self-benefit [16-21] (but see [22-25]). Several factors have been proposed to modulate these behaviors, namely familiarity [6, 13, 18, 20] or display of seeking behavior [16, 21]. Rats have been recently shown to be prosocial under distress [17, 18] (but see [26-29]); however, what drives prosociality in these animals remains unclear. To address this issue, we developed a two-choice task in which prosocial behavior did not yield a benefit or a cost to the focal rat. We used a double T-maze in which only the focal rat controlled access to the food-baited arms of its own and the recipient rat's maze. In this task, the focal rat could choose between one side of the maze, which yielded food only to itself (selfish choice), and the opposite side, which yielded food to itself and the recipient rat (prosocial choice). Rats showed a high proportion of prosocial choices. By manipulating reward delivery to the recipient and its ability to display a preference for the baited arm, we found that the display of food-seeking behavior leading to reward was necessary to drive prosocial choices. In addition, we found that there was more social investigation between rats in selfish trials than in prosocial trials, which may have influenced the focals' choices. This study shows that rats provide access to food to others in the absence of added direct self-benefit, bringing new insights into the factors that drive prosociality.


Assuntos
Altruísmo , Comportamento de Escolha/fisiologia , Comportamento Alimentar/fisiologia , Comportamento Social , Análise de Variância , Animais , Aprendizagem em Labirinto , Ratos , Recompensa
19.
Psychopharmacology (Berl) ; 167(2): 195-202, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12652345

RESUMO

RATIONALE: There is evidence for alterations in imidazoline(2) (I(2)) receptor density in depressed patients. Selective I(2) receptor ligands modulate central monoamine levels and activate the hypothalamo-pituitary-adrenal (HPA) axis and may have potential as antidepressants. OBJECTIVES: To study the behavioral effects of the selective I(2) receptor ligand BU224 in the rat forced swim test (FST) and its effects on the HPA axis and central monoaminergic responses. METHODS: Rats received saline or BU224 (10 mg/kg IP) 24, 18 and 1 h prior to 15 min exposure to the FST. Saline- and BU224-treated non-stressed groups were included. Time spent immobile, struggling and swimming calmly was measured. Plasma adrenocorticotrophic hormone (ACTH) and corticosterone levels 90 min post-BU224 were measured in addition to tissue levels of monoamines and metabolites in the frontal cortex, hippocampus and hypothalamus. RESULTS: Administration of BU224 significantly reduced immobility and increased mild swimming without affecting struggling. Exposure to the FST significantly increased plasma ACTH and corticosterone levels. BU224 administration also increased ACTH and potentiated the ACTH response to FST with no effect on corticosterone. BU224 administration significantly increased frontal cortex 5-hydroxytryptamine (5-HT) levels and decreased 5-HT turnover in the frontal cortex and hypothalamus of rats exposed to FST. In non-stressed rats, BU224 decreased 5-HT turnover in the hippocampus and hypothalamus and decreased norepinephrine turnover in the frontal cortex. CONCLUSIONS: The selective I(2) receptor ligand BU224 reduces immobility of rats in the FST, indicative of antidepressant-like activity. This effect is accompanied by alterations in HPA axis and central monoaminergic activity.


Assuntos
Antidepressivos/farmacologia , Comportamento Animal/efeitos dos fármacos , Imidazóis/farmacologia , Receptores de Droga/efeitos dos fármacos , Estresse Psicológico , Hormônio Adrenocorticotrópico/sangue , Animais , Corticosterona/sangue , Lobo Frontal/efeitos dos fármacos , Lobo Frontal/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Receptores de Imidazolinas , Ligantes , Masculino , Atividade Motora/efeitos dos fármacos , Norepinefrina/metabolismo , Radioimunoensaio , Ratos , Ratos Sprague-Dawley , Serotonina/metabolismo , Estresse Psicológico/metabolismo , Estresse Psicológico/psicologia , Natação
20.
Behav Brain Res ; 154(2): 399-408, 2004 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-15313027

RESUMO

We have previously observed that a single exposure to immobilization (IMO), a severe stressor, caused long-term (days to weeks) desensitization of the response of the hypothalamic-pituitary-adrenal (HPA) axis to the homotypic stressor, with no changes in behavioral reactivity to novel environments. In contrast, other laboratories have reported that a single exposure to footshock induced a long-term sensitization of both HPA and behavioral responses to novel environments. To test whether these apparent discrepancies can be explained by the use of different stressors or different strains of rats, we studied in the present work the long-term effects of a single exposure to two different stressors (footshock or IMO) in two different strains of rats (Sprague-Dawley from Iffa-Credo and Wistar rats from Harlan). We found that both strains showed desensitization of the HPA response to the same (homotypic) stressor after a previous exposure to either shock or IMO. The long-term effects were higher after IMO than shock. No major changes in behavior in two novel environments (circular corridor, CC and elevated plus-maze, EPM) were observed after a single exposure to shock or IMO in neither strain, despite the fact that shocked rats showed a conditioned freezing response to the shock boxes. The present results demonstrate that long-term stress-induced desensitization of the HPA axis is a reliable phenomenon that can be observed with different stressors and strains. However, only behavioral changes related to shock-induced conditioned fear were found, which suggests that so far poorly characterized factors are determining the long-term behavioral consequences of a single exposure to stress.


Assuntos
Comportamento Animal/fisiologia , Sistema Hipotálamo-Hipofisário/fisiologia , Sistema Hipófise-Suprarrenal/fisiologia , Estresse Fisiológico/fisiopatologia , Hormônio Adrenocorticotrópico/metabolismo , Análise de Variância , Animais , Corticosterona/metabolismo , Eletrochoque/efeitos adversos , Comportamento Exploratório/fisiologia , Imobilização/efeitos adversos , Masculino , Aprendizagem em Labirinto , Desempenho Psicomotor/fisiologia , Radioimunoensaio/métodos , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Tempo de Reação , Especificidade da Espécie , Estresse Fisiológico/metabolismo , Fatores de Tempo
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