The elevated gradient of aversion: a new apparatus to study the rat behavior dimensions of anxiety, fear, and impulsivity.

Few behavioral tests allow measuring several characteristics and most require training, complex analyses, and/or are time-consuming. We present an apparatus based on rat exploratory behavior. Composed of three different environments, it allows the assessment of more than one behavioral characteristic in a short 3-min session. Factorial analyses have defined three behavioral dimensions, which we named Exploration, Impulsivity, and Self-protection. Behaviors composing the Exploration factor were increased by chlordiazepoxide and apomorphine and decreased by pentylenetetrazole. Behaviors composing the Impulsivity factor were increased by chlordiazepoxide, apomorphine, and both acute and chronic imipramine treatments. Behaviors composing the Self-protection factor were decreased by apomorphine. We submitted Wistar rats to the open-field test, the elevated-plus maze, and to the apparatus we are proposing. Measures related to exploratory behavior in all three tests were correlated. Measures composing the factors Impulsivity and Self-protection did not correlate with any measures from the two standard tests. Also, compared with existing impulsivity tests, the one we proposed did not require previous learning, training, or sophisticated analysis. Exploration measures from our test are as easy to obtain as the ones from other standard tests. Thus, we have proposed an apparatus that measured three different behavioral characteristics, was simple and fast, did not require subjects to be submitted to previous learning or training, was sensitive to drug treatments, and did not require sophisticated data analyses.

The elevated gradient of aversion: a new apparatus to study the rat behavior dimensions of anxiety, fear, and impulsivity

Few behavioral tests allow measuring several characteristics and most require training, complex analyses, and/or are time-consuming. We present an apparatus based on rat exploratory behavior. Composed of three different environments, it allows the assessment of more than one behavioral characteristic in a short 3-min session. Factorial analyses have defined three behavioral dimensions, which we named Exploration, Impulsivity, and Self-protection. Behaviors composing the Exploration factor were increased by chlordiazepoxide and apomorphine and decreased by pentylenetetrazole. Behaviors composing the Impulsivity factor were increased by chlordiazepoxide, apomorphine, and both acute and chronic imipramine treatments. Behaviors composing the Self-protection factor were decreased by apomorphine. We submitted Wistar rats to the open-field test, the elevated-plus maze, and to the apparatus we are proposing. Measures related to exploratory behavior in all three tests were correlated. Measures composing the factors Impulsivity and Self-protection did not correlate with any measures from the two standard tests. Also, compared with existing impulsivity tests, the one we proposed did not require previous learning, training, or sophisticated analysis. Exploration measures from our test are as easy to obtain as the ones from other standard tests. Thus, we have proposed an apparatus that measured three different behavioral characteristics, was simple and fast, did not require subjects to be submitted to previous learning or training, was sensitive to drug treatments, and did not require sophisticated data analyses.

Early maternal separation induces preference for sucrose and aspartame associated with increased blood glucose and hyperactivity.

Early life stress and exposure to sweeteners lead to physiological and behavioral alterations in adulthood. Nevertheless, many genetic and environmental factors as well as the neurobiological mechanisms that contribute to the development of these disorders are not fully understood. Similarly, evidence about the long-term metabolic effects of exposure to sweeteners in early life is limited and inconsistent. This study used an animal model of maternal separation during breastfeeding (MS) to analyze the effects of early life stress on consumption of sweeteners, weight gain, blood glucose and locomotion. Rats were housed under a reversed light/dark cycle (lights off at 7:00 h) with ad libitum access to water and food. In the MS protocol, MS pups were separated from the dam for 6 h per day in two periods of 180 minutes (7:00-10:00 and 13:00-16:00 h) during the dark phase of postnatal day (PND) 1 to PND 21. Non-separated (NS) pups served as controls. On PND 22 rats were grouped by sex and treatment. From PND 26 to PND 50 sucrose and aspartame were provided to rats, and sweetener intake, body weight and blood glucose-related measures were scored. On PND 50, both male and female rats were exposed to the open field test to obtain locomotion and anxiety-related measures. Results showed that both early maternal separation and sweetener intake during adolescence resulted in increased blood glucose and hyperactivity in male rats but not in female rats. Data suggest that the combination of early stress and exposure to sucrose and aspartame could be a risk factor for the development of chronic diseases such as diabetes, as well as for behavioral alterations.

Synthesis of MoS(2) nanorods and their catalytic test in the HDS of dibenzothiophene.

Partially sulfided nanostructures were synthesized by direct sulfurization of alpha-MoO(3) nanorods using a mixture of H(2)S/H(2), 15 vol%, at several temperatures (400, 500, 600, 700, and 800 degrees C). These materials were tested as catalysts in the hydrodesulfurization (HDS) of dibenzothiophene (DBT) and characterized by specific surface areas using the expression developed by Brunauer, Emmett, and Teller (BET equation), x-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The TEM images show a gradual evolution from a smooth surface to a rough material, presenting some type of holes all over the particles, but keeping their rod-like structure throughout sulfidation. The results of evaluating the catalysts in the HDS of DBT showed that the best temperature for sulfidation is 500 degrees C. In all samples, a higher selectivity for hydrogenation over sulfur removal was observed.