Biomedical subjects

M C Carrasco

Publications and source records attributed to M C Carrasco.

9 recordsLinked to original sources

PubMed2005

Effects of acute bupropion administration on locomotor activity in adolescent and adult mice.

Responses to some psychoactive substances seem to differ between adolescents and adults. Bupropion, an antidepressant which is also used for smoking cessation, induces a dose-dependent increase in locomotor activity in adult mice, although its behavioral actions in adolescents have not been evaluated. In the present study the effects of acute bupropion administration (5, 10, 15 and 20 mg/kg) on locomotor activity were examined in early adolescent (postnatal day (pnd): 29-31 days), late adolescent (pnd: 47-49 days) and adult (pnd > 70 days) male NMRI mice, using an infrared photocell system. Locomotion was recorded for a total period of 90 min. Results indicated that there were significant differences in motor activity counts between the three ages evaluated, with late adolescents being more active than early adolescents. Bupropion (at doses 20, 15 and 10 mg/kg) induced a significant increase in locomotion, but there was no significant interaction between age and treatment. This suggests that the locomotor-stimulating effects of bupropion can be observed at different ages (early adolescence, late adolescence and adulthood), although the detailed analysis of the temporal course of locomotion changes induced by different bupropion doses reflected some differences between ages. The lowest dose (5 mg/kg) failed to induce hyperactivity in either adolescent or adult mice.

Aging↗

PubMed2003

Spatial learning in male mice with different levels of aggressiveness: effects of housing conditions and nicotine administration.

The main aim of the present investigation was to evaluate the possible modulation of spatial learning ability by housing conditions and level of aggressiveness in mice, also testing whether differences in locomotion and anxiety could influence this relationship. Additionally, we have examined effects of nicotine in the acquisition and retention of a spatial learning task in groups of mice differing in these variables. NMRI male mice were either group-housed or individually housed for 30 days and then classified into mice with short (SAL) and long (LAL) attack latency after a pre-screening agonistic encounter. Locomotor activity and baseline levels of anxiety of these groups were evaluated in the actimeter and elevated plus-maze. Results indicated that SAL and LAL individually housed mice displayed higher locomotion activity than LAL group-housed mice. In the plus-maze test, SAL and LAL individually housed mice showed more total and open arm entries than group-housed LAL mice, confirming the hyperactivity of individually housed mice and suggesting that isolation had no clear anxiolytic or anxiogenic actions. In the water-maze, we compared the performance of individually housed SAL, individually housed LAL mice, and group-housed LAL mice treated with nicotine (0.35 and 0.175 mg/kg) or vehicle. Nicotine did not improve acquisition in group-housed mice and even impaired it in individually housed mice. Retention of platform position was better in vehicle-treated individually housed mice in comparison with vehicle-treated group-housed mice. The present study demonstrates that housing conditions but not level of aggressiveness modify spontaneous locomotor activity and behaviors displayed on the elevated plus-maze test, and can also influence retention of a spatial learning task.

Aggression↗

PubMed2002

Effects of early spatial training on water maze performance: a longitudinal study in mice.

The aim of the present study is to establish whether in mice the effects of an early experience in the Morris water maze are maintained after a long period. A longitudinal study was performed in which mice of two different strains (NMRI and C57) received spatial training at 2 months of age and their performance was re-evaluated 8 and 16 months later. In both strains, results showed a beneficial effect of prior experience on this spatial memory task even 8 months after the initial training. At 18 months of age, performance of C57 mice that were trained at 2 months of age for the first time was similar to those who received their first training at 10 months of age. These findings suggest that the beneficial effect of previous training could be limited by time. In addition, water maze performance of 18 month-old C57 mice did not differ from their earlier performance when they were 10 months of age, which would indicate that experience in this task could prevent some of the age-related spatial learning deficits observed in mice.

Adaptation, Physiological↗

PubMed2001

Time estimation and aging: a comparison between young and elderly adults.

Studies about effects of aging on the estimation of short temporal intervals are not conclusive. The aim of the present research was to evaluate age-related differences in the reproduction of a short interval (10 s) using a computerized method. The sample comprised thirteen young adults (M = 26.15 years) and twelve elderly adults (M= 79.1 years). Three parameters of time estimation were measured: estimated time, absolute error, and standard deviation. Results showed that time estimates performed by elderly participants were shorter than those of younger ones, although there were no significant differences between the two age groups in the percentage of absolute errors or standard deviations. These findings could be explained by changes in the rate of the internal clock or to an interaction between more general changes in cognitive processes.

Adult↗

PubMed1999

Previous training in the water maze: differential effects in NMRI and C57BL mice.

It has been shown that acquisition rates in the water maze vary across strains of mice, although the differential effects of previous experience in this spatial task have been scarcely evaluated. The aim of the present study was to evaluate the effects of training in the water maze at an early age (2 months) in two strains of mice (NMRI and C57BL) using a longitudinal study. Mice with or without previous training were tested when they were 6 months, and retested when 10 months old. The results showed that trained NMRI mice performed better than all the other groups, both at test and retest, indicating that previous training had more beneficial effects in NMRI than in C57BL mice. These results demonstrate that the effects of an early training in the water maze may be influenced by the characteristics of the strain of mice. It could have implications in longitudinal studies evaluating effects of pharmacological or behavioral manipulations.

Age Factors↗

PubMed1999

Effects of nicotine on spatial learning in C57BL mice.

In the present study, the effects of nicotine on spatial memory in C57BL/6J mice was evaluated. Mice were trained in a water maze during four daily sessions of three trials each. In the first experiment, nicotine (0.7 and 0.35 mg/kg) or saline was administered once daily for 4 days, 15 min before the start of daily training: an impairment of performance of the water maze was observed in the group treated with 0.7 mg/kg of nicotine. In the second experiment, nicotine (0.7 and 0.35 mg/kg) or saline was administered from the 5 days prior to the beginning of the task and during the 4 days of acquisition. The results indicated an improvement in the rate of learning in the 9-day nicotine treated groups. The comparison between 4-day and 9-day treated groups revealed that the group receiving 0.35 mg/kg of nicotine for 9 days displayed significantly shorter latencies than all the other groups, while the group receiving 0.7 mg/kg of nicotine for 4 days performed significantly worse than all the other groups. The most noteworthy result is that nicotine was more effective after a more prolonged administration than when administered only during the training days.

Animals↗

PubMed1995

A histochemical study of the biological effects of sodium dodecyl sulfate on the intestine of the gilthead seabream, Sparus aurata L.

This paper reports the morphological and histochemical changes caused by acute action of the detergent sodium dodecyl sulfate (SDS) on the intestine of the gilthead (Sparus aurata L.). Sixty-five giltheads were exposed to SDS concentrations of 5, 8.5, 10, and 15 mg/liter. Surface tensions were determined and the LC50 values calculated. The effects of SDS on the intestine were more pronounced in those specimens exposed to higher concentrations and for longer periods. Three causes of death were determined: (i) decrease in surface tension, (ii) destruction of tissue, and (iii) alteration of biomacromolecules. Both (ii) and (iii) were determined by histochemical techniques.

Animals↗

PubMed1995

Morphological and histochemical changes in the liver and pancreas of gilthead, Sparus auratus L., induced by acute action of the anionic detergent, sodium dodecyl sulphate.

This paper reports the morphological and histochemical changes in the livers and pancreas of giltheads (Sparus auratus, L.) induced by acute action of the anionic detergent, sodium dodecyl sulphate (SDS). Sixty-five giltheads were exposed to SDS concentrations of 5, 8.5, 10 and 15 mg/l. The surface tension induced at each concentration was determined and the LC50 calculated. Morphological changes dependent on detergent concentrations and length of exposure were seen. Histochemical techniques showed alterations in carbohydrates and proteins, which may interfere with liver and pancreas function.

Animals↗

PubMedDate not supplied

Estimation of short temporal intervals in Alzheimer's disease.

This study investigated the estimation of short temporal intervals in Alzheimer's disease (AD). Eight patients with dementia of the Alzheimer type, and eight age-matched controls were evaluated in a time-estimation task. The task consisted in the production of three short empty intervals (5, 10, and 25 s). Results indicated that AD patients show deficits both in the accuracy and precision of time judgments: in the three intervals evaluated, the magnitude of absolute error and the variability in time judgments were significantly greater in AD patients than healthy respondents (p < .01). These findings are discussed taking into account the contribution of attentional processes during the performance of temporal tasks. It is concluded that the estimation of short temporal intervals could be useful as an objective indicator of cognitive decline in AD.

Aged↗