Resumo em Inglês:

Luiz Marcellino de Oliveira (1939-2008) had an influential participation in almost every moment of the history of the Department of Psychology and Education, FFCLRP, as well as at different moments of the history of the Brazilian Psychology. This paper examines issues related to his pioneer work as a teacher of experimental analysis of behavior and as a psychobiological investigator in Brazil. Emphasis is given to his dedication to the development of science and to the consolidation of a scientific approach to Psychology in Brazil at the level of teaching and of experimental investigation. He contributed with investigations on the effects of drugs and malnourishment on behavior and brain development, conducting experimental analysis of behavior and neurochemical and electrophysiological analysis of the nervous system of the malnourished organism, as well as putting emphasis on environmental stimulation as a valuable intervention. Both as a teacher and as a researcher he exerted a prime influence on numerous professionals and members of the academic community that during more than forty years had the privilege of benefiting from his friendship and knowledge.

Resumo em Inglês:

The aim of this work was to assess the relationship between nutritional status and body image perception in Brazilian adults. Participants included 280 adults (18-60 years) of both genders. The sample was composed proportionally to the Brazilian nutritional status distribution according to body mass index, with volunteers of all economic classes and educational levels. We applied a Figure Rating Scale to examine body image concerning size and shape. Both men and women were dissatisfied with their body size. Regarding body discrepancy, eutrophic adults overestimated their body size and desired leaner bodies. Our results also showed that the higher the BMI, the smaller the differences between men and women. These findings reinforce that body image perception is an important factor to be considered by health professionals in order to improve quality of life.

Resumo em Inglês:

The present study investigated the effects of protein malnutrition and environmental stimulation on biochemical and behavioral parameters in rats. The concentrations of polyamines in the frontal cortex, striatum, and hippocampus, as well as plasma corticosterone levels, were measured. The exploratory behavior was analyzed using the elevated plus-maze (EPM) test. Rats received either 16% (well-nourished - W) or 6% (malnourished - M) protein diets and were divided into stimulated or non-stimulated groups. Malnutrition increased corticosterone levels and decreased plasma protein and anxiety. Non-stimulated rats tested in the EPM had increased corticosterone levels and decreased frontal cortex, striatum and hippocampus protein and polyamines contents. Stimulation decreased open arm entries in the EPM in M animals and increased closed arm entries in the W ones. Stimulation increased frequency and time spent in risk-assessment behaviors. These results suggest that both malnutrition and EPM testing are distressing situations, as indicated by increased corticosterone levels. These results are consistent with lower anxiety and/or higher impulsiveness in M animals.

Resumo em Inglês:

There is evidence that the auditory evoked potential (AEP) is altered by malnutrition both in laboratory animals and in humans. The objective of the present study was to determine whether changes in the AEP caused by malnutrition could be reversed by nutritional rehabilitation and sensorymotor and environmental stimulation during hospitalization. Six children aged 5-33 months with severe malnutrition (kwashiorkor, marasmus and marasmic-kwashiorkor) were admitted to the Pediatric Ward of a University Hospital. Normal age and sex-matched children from the hospital day-care center were enrolled as a control group. The AEP was tested in an electrically and acoustically isolated room using a Nicolet CA 2000 microcomputer. Clicks of 90; 80; 70 and 60 dBn HL were presented through earphones. The results suggest that malnutrition leads to an increase in wave I latencies in patients with marasmus, and in waves I, III and V in those with kwashiorkor or marasmic-kwashiorkor type at 90 dB HL. At discharge, all but one patient with kwashiorkor showed reduced latencies of waves I, III and V compared to the values on admission. Despite the small sample, these preliminary results pointed out that the process of sensory stimulation used in our study in a properly directed, systematic and individualized manner showed encouraging results in terms of AEP recovery in these children.

Resumo em Inglês:

Iron deficiency alters metabolism, neurotransmission, glial integrity and the cortical myelin layer, besides increasing myelinization time. Environmental stimulation (handling) improves morphological, biochemical, electrophysiological and behavioral aspects of both well-nourished and malnourished animals. The objective of the present study was to determine the effects of an irondeficient diet and of handling on the brainstem auditory evoked potential (BAEP) of rats during development. Ninety-six male rats were divided since birth into Well-nourished (W, 35 mg iron/kg) and Anemic (A, 4 mg iron/kg) groups, and subdivided into Handling (H) and No Handling (NH). Body weight, hemoglobin (Hb), hematocrit (Ht), latencies of waves I, II, III IV, I-IV interpeak interval, and response threshold to auditory stimuli were evaluated at 18, 22, and 32 days. W animals presented higher Hb and Ht levels than A animals at 18, 22 and 32 days. The animals presented longer latencies of waves I, II, III and IV and I-IV interpeak interval of BAEP at 18 than at 22 and 32 days, and AH18 rats presented longer latencies of waves I and II than AH22 and AH32 rats, and longer wave I latency than WH18 animals. Iron deficiency increased the latencies of BAEP waves, suggesting damage to the myelin layer, especially during the early development, and the effects of handling were more evident along time in anemic animals.

Resumo em Inglês:

In associative learning, experience enables an animal to associate a conditioned stimulus with some other meaningful stimulus producing either positive or negative effects. In this way, on a subsequent encounter, the response that was previously elicited only by the meaningful stimulus is then elicited by the conditioned stimulus as well. The aim of the present study was to investigate whether wild Anastrepha obliqua (Macquart, 1835) females are able to associate the presence of quinine sulphate (QS) in the composition of oviposition substrates with the presence of brewer's yeast (a protein source). First, the females were submitted to an experience period with artificial substrate containing brewer's yeast + QS (YQS substrate). After this period, the females were allowed to choose between substrates with or without QS. In one group, the substrates contained brewer's yeast (YQS x Y substrates); in the other group, the substrates contained only agar (AQS x A substrates). In the YQS x Y choice situation, a smaller quantity of eggs was found on YQS substrates, only on the first choice day. In the AQS x A choice situation, there was no preference for one of the substrates on each of the three choice days. However, we think it is too early to state that A. obliqua females are not able to perform the association in question. These flies show a high behavioral flexibility concerning their oviposition behavior strategies. Besides, this behavior, in this species, includes several stages. Based on it, possible explanations for the results are discussed in this study.

Resumo em Inglês:

Every second, in an average daytime light environment, hundreds of millions of photons enter the human eye and arrive at the photoreceptor layer of the retina. All our information about the visible world is contained in this rain of photons. The retina is a complex tissue, literally an extension of the brain, which transforms the rain of photons into bioelectric signals containing all the information available to the brain to interpret and respond to the external visual world. A considerable amount of processing takes place within the retinal tissue itself. Understanding what kind of processing takes place at each retinal stage is crucial for understanding normal vision, vision in the presence of diseases affecting the retina, and, ultimately, for the development of therapies to treat such diseases. This manuscript reviews the relation between structure and function of the different retinal pathways and addresses their possible roles for visual perception.

Resumo em Inglês:

A great deal of studies using different visual tasks (e.g., Vernier acuity tasks, tilt illusion, crowding, etc) have revealed that our perception is strongly influenced by the orientation of the stimulus. Most studies have investigated visual acuity in two-dimensional visual spaces (2D) but little is known about the effect of line orientation in depth perception (3D). In one experiment, Vernier Acuity (VA) in frontoparallel (2D) and medial (3D) planes was investigated. We used a virtual reality setup inducing inter-ocular disparities to simulate a 3D visual space, and a common computer screen to present stimuli in the frontal plane. In the experiment, by using the method of constant stimuli, the observer compared VA in the 2D and 3D visual spaces as a function of the stimulus orientation. Results showed that only judgments in the 3D condition were affected by the well-known 'oblique effect', and some impairment in stereoacuity (lines in depth plane) in comparison to 2D acuity (lines in frontal plane) was observed. We attributed the cause for such deterioration in stereoacuity to changes in vertical disparities.

Resumo em Inglês:

Current theoretical models of emotion highlight the importance of distinguishing depression and anxiety. The present article critically evaluates a number of these models and provides a practical framework that could be applied in future studies to better understand the neural substrates that contribute to variation in anxiety and depressed mood. One influential model, the tripartite model, suggests that depression and anxiety can be distinguished on the basis of anhedonia and hyperarousal. Yet this model is based predominantly on questionnaire data. A more direct and powerful method to test this model is to identify biological markers of arousal and anhedonia. Other influential models, such as the approach-withdrawal and valence-arousal models, are based on biological measures and integrate the concept of arousal - but have generally restricted empirical enquiry into resting state paradigms, without an integrative approach to explore concurrent physiological arousal using autonomic measures, or to extend into emotion processing paradigms. The authors propose a practical framework that will have significant implications for theoretical models of depression and anxiety including integration of influential models of emotion and advancement of the knowledge base, clarification of the neurobiological specificity of depression and anxiety and identification of overlapping and distinctive features of these disorders.

Resumo em Inglês:

This study aimed at investigating differences in the performance of the young elderly and oldest old in tasks evaluating cognitive flexibility/inhibition (Stroop test), selective attention/working memory (Digit Span Subtest), premorbid intelligence/semantic knowledge (Vocabulary Subtest), and decision making (Iowa Gambling Task - IGT). Twenty healthy individuals were divided into two groups: 10 young elderly (M = 62 years, SD = 2.1) and 10 oldest old (M = 80 years, SD = 3.3), both with high educational level (M = 14 years of study, SD = 2.5). Results showed that the groups were only different in terms of decision making. There was also a difference in the learning process of each group; the young elderly reached more favorable scores in the IGT.

Resumo em Inglês:

The present work aimed at studying the influence of the estrous cycle in the forced swim test, an animal model of depression. For this, 44 male and female Wistar rats were divided into five groups according to the hormonal state in the first day of the study: metaestrus (N = 12), diestrus (N = 8), proestrus (N = 7), estrous (N = 6) and males (N = 11). They were housed in groups of five, with water and food ad libitum under a 12/12 h light/dark cycle. Females were screened daily for the estrous cycle. The animals were subjected to two swimming sessions in a glass cylinder with water up to 15 cm at 28±2º C. The data of the first five minutes of a 15-min first session were compared to those of a 5-min second session 24 h later. The results indicate that the latency to the first immobility was substantially reduced in the second session and was longer for females in diestrus and proestrus in the first session. The results also indicate that females in diestrus and proestrus exhibited less immobility than males in the first session; females in diestrus also exhibited less immobility than females in metaestrus. Females in metaestrus and diestrus, as well as males, did not present the decrease in total immobility times in the second session. The present results are analyzed in terms of differential effects of progesterone and estrogen on a learning component and an affective component.