No abstract

It is well known that the metabolism of alcohol and cognitive functions can vary during the menstrual cycle. Also, both alcohol ingestion and hormonal variations during menstruation have been associated with characteristic changes in electroencephalographic (EEG) activity. The aim of the present study was to determine whether EEG activity during the performance of the Tower of London (TOL) task is affected by previous ingestion of alcohol and whether these EEG patterns vary in relation to different phases of the menstrual cycle. For this purpose, female participants consumed a moderate dose of alcohol or placebo during the follicular and early luteal phases of the menstrual cycle and then, 35 min after liquid ingestion, EEG activity was recorded during the performance of TOL. A deleterious effect of alcohol on TOL performance was potentiated in the follicular phase, related to a higher α1 relative power, probably as a result of the low progesterone levels characteristic of this menstrual phase. These data show the feasibility of examining the interaction of alcohol and menstrual cycle phases on cognitive performance by means of EEG recording, and contribute toward a better understanding of the brain mechanisms that underlie the cognitive changes that occur during the menstrual cycle under the effects of alcohol.

Chronic early life stress (ECS) induced by limited bedding and nesting (LBN) material in rodents is a naturalistic stress model that mimics many of the behavioral and neural consequences of child abuse and neglect; however, the effect of ECS on adult impulsivity has never been studied. The aim of our work was to determine the effects of ECS on cognitive impulsivity and its relation to D2 immunoreactivity in the nucleus accumbens (NAc) and prefrontal cortex (PFC) of adult male rats. Sprague-Dawley rats were exposed to LBN from postnatal day 2 to 9. We evaluated dams' maternal behavior and offspring corticosterone levels. The rats' impulsive cognitive behavior was evaluated by a delay-discounting task (transitional bridge) on P70, and we evaluated D2 receptors by immunostaining. Our results indicated that ECS affected maternal behavior in the dams and increased pups' corticosterone levels at P9, but not in adults. ECS rats showed lower frequencies of choosing the delayed reinforcer and shorter latencies to cross on the delay-discounting task. In addition, ECS rats showed increased D2 immunoreactivity in the NAc when compared with controls. Our data suggest that ECS can cause impulsive behaviors in adult rats characterized by less convenient choices, likely related to an increase in D2 receptors in the NAc. These findings could contribute to our understanding of the effects of child abuse and neglect on impulsive behavior.

The quantitative analysis of electroencephalographic activity (EEG) is a useful tool for the study of changes in brain electrical activity during cognitive and behavioral functions in several experimental conditions. Their recording and analysis are currently carried out primarily through the use of computer programs. This paper presents a computerized program (EEGbands) created for Windows operating systems using the Delphi language, and designed to analyze EEG signals and facilitate their quantitative exploration. EEGbands applies Rapid Fourier Transformation to the EEG signals of one or more groups of subjects to obtain absolute and relative power spectra. It also calculates both interhemispheric and intrahemispheric correlation and coherence spectra and, finally, applies parametrical statistical analysis to these spectral parameters calculated for wide frequency EEG bands. Unlike other programs, EEGbands is simple and inexpensive, and rapidly and precisely generates results files with the corresponding statistical significances. The efficacy and versatility of EEGbands allow it to be easily adapted to different experimental and clinical needs.

EEGcorco is a computer program designed to analyze the degree of synchronization between two electroencephalographic signals (EEG) by mean the analysis of correlation and coherence index. The correlation and coherence values permit the quantitative determination of the similarity among EEG signals from homologous areas of the cerebral hemispheres (interhemispheric), and among localized areas within one cerebral hemisphere (intrahemispheric). EEG coherence is a function of frequency; thus it is commonly presented in a spectral manner (coherence values in every frequency of the spectrum), in contrast, the correlation function has been employed mainly to search periodic components of bioelectrical signals, and normally appears as punctual values defined in time, hence it is not common calculate correlation spectra. EEGcorco offers an easy and novel way to calculate correlation spectra by mean the application of the Fast Fourier Transformation (FFT) to digitized EEG signals. Both, correlation and coherence spectra are obtained in both independent frequencies and frequencies grouped in wide bands. Moreover, the program applies parametric statistical analyses to those coherence and correlation spectra also, for each individual frequency and for the frequencies grouped in bands. The program functions on any PC-compatible computer equipped with a Pentium or superior processor and a minimum of 512 Mb of RAM memory (though the higher the capacity the better). The space required on the hard disk depends on the signals to be analyzed, as the output takes the form of files in text format that occupy very little space. The program has been elaborated completely in the Delphi environment for the Windows operating system. The efficacy and versatility of EEGcorco allow it to be easily adapted to different experimental and clinical needs