Casi toda la investigación farmacológica en estrés y desórdenes de ansiedad es realizada generalmente en poblaciones de animales que se supone son comparables. En el laboratorio de Neurociencia Comportamental de la Pontificia Universidad Católica de Río de Janeiro (Brasil), dos nuevas líneas de ratas Wistar fueron aisladas por la selección fenotípica de la respuesta emocional en el protocolo de condicionamiento de la respuesta de miedo. Una de las líneas, denominada Carioca High Freezing (CHF) muestra una respuesta aumentada de congelamiento en el test, mientras que la otra -Carioca Low Freezing (CLF)- muestra la respuesta opuesta. Aquí presentamos datos orientados a evaluar las condiciones basales y la vulnerabilidad al estrés entre las dos líneas. Los niveles de corticosterona fueron comparados entre las dos líneas tanto en condiciones basales como después de un desafío emocional utilizando el protocolo de miedo condicionado. La comparación entre las concentraciones plasmáticas de corticosterona basal y luego del retest sugiere diferencias basales y diferencias inducidas por el miedo entre las dos líneas. Las diferencias en las condiciones basales es un aspecto importante y relevante que debe ser considerado en experimentos comportamentales que usen o evalúen el estrés y podría ayudar a comprender la variabilidad encontrada en las poblaciones.

Our group in the Psychology Department at Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio) developed a rat genetic model of extreme freezing in response to contextual cues in an experimental chamber previously associated with footshock. One of the lines, Carioca High Freezing (CHF), exhibits an enhanced conditioned freezing response, whereas the other line, Carioca Low Freezing (CLF), shows the opposite response. The present study investigated corticosterone concentration between these two lines of animals and a random (RND) line of rats both under basal conditions and test condition after an emotional challenge using a contextual fear conditioning protocol. Comparisons between basal and test plasma corticosterone concentrations suggested differential basal and fear-induced differences between the two lines. The differences between basal conditions is an important and relevant aspect to be considered in behavioral experiments using or assessing stress and could help to understand variability in naïve populations.

Nosso grupo no Departamento de Psicologia da Universidade Católica do Rio de Janeiro desenvolveu um modelo genético com ratos que apresentam respostas extremas de congelamento a estímulos contextuais de uma caixa experimental previamente associados a choques elétricos. Uma das linhagens, Carioca High Freezing (CHF) apresenta uma resposta aumentada de congelamento condicionado. A outra linhagem, Carioca Low Freezing (CLF) apresenta a resposta de congelamento condicionada em direção oposta. O presente trabalho comparou os níveis de corticosterona entre as duas linhagens assim como uma terceira linhagem com cruzamento aleatório (RND) tanto em condições basais assim como em um teste onde os animais foram expostos á situação de condicionamento contextual de medo. A comparação entre as concentrações plasmáticas de corticosterona basal e depois do teste sugere diferenças basais assim como diferenças induzidas pelo medo condicionado entre as duas linhagens. As diferenças nas condições basais é um aspecto importante e relevante que deve ser levado em consideração em experimentos que avaliem o estresse e pode ajudar na compreensão da variabilidade nas populações.

Reportamos aquí los efectos de la administración subcrónica de 3, 4-metilendioximetanfetamina (MDMA) sobre el laberinto en cruz elevado, un modelo animal de ansiedad ampliamente utilizado. Las ratas fueron expuestas a un protocolo de estrés crónico moderado (MCS) y recibieron microinyecciones intra-cerebroventriculares del inhibidor selectivo de la recaptación de serotonina (SSRI)-fluoxetina (2,0 ug/ul) o de MDMA (0,2 ug/ul) durante siete días. En el octavo día las ratas fueron probadas en el laberinto en cruz elevado. Los resultados mostraron que la administración subcrónica de MDMA interactuó con el MCS, llevando a un decremento de los comportamientos relacionados con la ansiedad, incluyendo: porcentaje de entradas a los brazos abiertos (F 26] = 4.00; p = 0.031), el tiempo empleado explorando los brazos abiertos (F[2, 26] = 3.656; p = 0.040) y el tiempo empleado explorando las extremidades de los brazos abiertos (F[2, 26] 26] = 5.842; p = 0.008). Estos resultados sugieren un potencial efecto de MDMA en la reversión del significado emocional de los estímulos aversivos.

Here we report the effects of subchronic 3, 4-methylenedioximethamphetamine (MDMA) on the elevated plusmaze, a widely used animal model of anxiety. Rats exposed to a mild chronic stress (MCS) protocol received intracerebroventricular microinjections of the selective serotonin reuptake inhibitor (SSRI) - fluoxetine (2.0 ug/ ul) or MDMA, (2.0 ug/ul) for seven days. On the eighth day rats were tested in the elevated plus-maze. Our results showed that sub-chronic MDMA interacted with MCS leading to a decrease in anxiety-related behaviors including: percentage of open arms entries (F[2, 26] = 4.00; p = 0.031), time spent in the open arms (F[2, 26] = 3.656; p = 0.040) and time spent in the open arms extremities (F[2, 26] = 5.842; p = 0.008). These results suggest a potential effect of MDMA in the reversion of the emotional significance of aversive stimuli.

Os efeitos da administração sub-crônica de 3, 4-metilenedioximetanfetamina (MDMA) no labirinto em cruz elevado, um modelo amplamente utilizado no estudo da ansiedade, foram testados. Ratos submetidos a um protocolo de estresse crônico moderado (MCS) receberam micro injeções intra cérebro ventriculares do inibidor seletivo da recaptação de serotonina (SSRI)-fluoxetina (2.0ug/ul) ou MDMA (2.0 ug/ul) durante sete dias. No oitavo dia, os ratos foram testados no labirinto em cruz elevado. Os resultados sugerem que a administração sub-crônica de MDMA interagiu com o MCS levando à diminuição dos comportamentos relacionados com ansiedade, incluindo: porcentagem de entradas aos braços abertos (F[2, 26] = 4.00; p = 0.031), o tempo gasto explorando os braços abertos (F[2, 26] = 3.656; p = 0.040) e o tempo gasto explorando as extremidades dos braços abertos (F[2, 26] = 5.842; p = 0.008).

El péptido BLMP-101 posee potencial para el tratamiento de deficiencias de la memoria. Esta investigación tuvo como objetivo corroborar los resultados obtenidos en investigaciones anteriores con respecto a la evaluación del péptido BLMP-101, en cuanto a la efectividad del péptido diseñado por el grupo de Bioquímica Computacional y estructural de la Pontificia Universidad Javeriana. Sin embargo, y a diferencia de las investigaciones anteriores, el objetivo del presente estudio consistió en medir la efectividad del BLMP-101, en dosis diferentes y haciendo la aplicación intrahipocampal del péptido, para corroborar sus efectos en la facilitación de la memoria espacial. Se utilizaron 31 ratas Wistar divididas en cuatro grupos, tres experimentales y uno de comparación. El grupo de comparación, fue inyectado con solución salina y a uno de los grupos experimentales se le administró NMDA y, a los otros dos, dosis diferentes del péptido BLMP-101 (0.3, 3.0 ug/ul). Los resultados sugieren que el péptido BLMP-101 con dosis de 3.0 ug/ul, facilitan la memoria espacial, mejor que el NMDA.

The BLMP-101 peptide has the potential features to treat memory deficiency. The herein research aimed at corroborating the results obtained in previous researches and tests conducted on the effectiveness of the peptide BLMP-101 designed by the Computational and Structural Biochemestry Unit of the Pontificia Universidad Javeriana, Colombia. However, and unlike previous researches, the objective of this paper measured the effectiveness of the BLMP-101peptide, when supplied in different dozes and through intrahipocampal application to confirm its effects to facilitate spatial memory. 31 Wistar rats were used into 4 different groups: three treatment groups and one control group. The control group was infused with saline solution, and one of the treatment groups was infused with NMDA, while the other two experimental groups were infused with different dozes of the BLMP-101peptide (0.3, 3.0 ug/ul). Results suggest that the BLMP-101 peptide, when supplied in 3.0 ug/ul, facilitates spatial memory showing better results than the NMDA.

Chronic administration of selective serotonin reuptake inhibitors (SSRI) enhances dopaminergic activity. However, the role of enhanced dopaminergic transmission in the therapeutic effects of this kind of antidepressants is still unclear. Drugs producing dopaminergic activation lead to an increment in general activity. Thus, it is reasonable to assume that some of the therapeutic effects of SSRIs are due to dopaminergic enhanced functionality. The forced swim test (FST) is a widely used test in the screening of new compounds with potential antidepressant activity. In this study the effects of pretreatment with low doses of the DA release inductor cocaine and the D2, D3 and D4 antagonist haloperidol were analyzed in the FST on rats submitted to chronic intragastric administration of the SSRI fluoxetine. Our results show that animals treated with fluoxetine and pre-treated with cocaine had significantly higher latencies than saline or haloperidol pre-treated subjects. Among both fluoxetine and saline treated animals, those pre-treated with cocaine had significant lesser immobility time. Haloperidol pre-treated animals had significantly higher immobility time than those pre-treated with saline. From these results, it is clear that the pharmacological modification of dopaminergic systems leads to behavioral changes in rats treated with both saline and fluoxetine. The FST does not have enough precision as to distinguish between dopaminergic and nondopaminergic components in the antidepressant effects of SSRIs, for this reason the use of the FST in combination to other models is mandatory.

A randomized trial of amphotericin B (AB) alone and in combination with oral itraconazole (IZ) is carried out in two groups of 10 mucocutaneous leishmaniasis patients from Bolivia and Peru. AB+IZ combination is no better than AB monotherapy, as far as efficacy and tolerability are concerned. No antagonism was detected.