Towards diversity in science - a glance at gender disparity in the Brazilian Society of Neuroscience and Behavior (SBNeC)

Gender equity is far from being achieved in most academic institutions worldwide. Women representation in scientific leadership faces multiple obstacles. Implicit bias and stereotype threat are considered important driving forces concerning gender disparities. Negative cultural stereotypes of weak scientific performance, unrelated to true capacity, are implicitly associated with women and other social groups, influencing, without awareness, attitudes and judgments towards them. Meetings of scientific societies are the forum in which members from all stages of scientific careers are brought together. Visibility in the scientific community stems partly from presenting research as a speaker. Here, we investigated gender disparities in the Brazilian Society of Neuroscience and Behavior (SBNeC). Across the 15 mandates (1978-2020), women occupied 30% of the directory board posts, and only twice was a woman president. We evaluated six meetings held between 2010 and 2019. During this period, the membership of women outnumbered that of men in all categories. A total of 57.50% of faculty members, representing the potential pool of speakers and chairs, were female. Compared to this expected value, female speakers across the six meetings were scarce in full conferences (χ2(5)=173.54, P<0.001) and low in symposia (χ2(5)=36.92, P<0.001). Additionally, women chaired fewer symposia (χ2(5)=47.83, P<0.001). Furthermore, men-chaired symposia had significantly fewer women speakers than women-chaired symposia (χ2(1)=56.44, P<0.001). The gender disparities observed here are similar to those in other scientific societies worldwide, urging them to lead actions to pursue gender balance and diversity. Diversity leads not only to fairness but also to higher-quality science.

Behavioral modulation by mutilation pictures in women

Previous studies have shown that women are more emotionally expressive than men. It is unclear, however, if women are also more susceptible to the emotional modulation of behavior imposed by an affective stimulus. To investigate this issue, we devised a task in which female subjects performed six sequential trials of visual target detection following the presentation of emotional (mutilation and erotic) or neutral pictures (domestic utensils and objects) and compared the data obtained in the present study with those described in a previous study with male subjects. The experiment consisted of three blocks of 24 pictures and each block had an approximate duration of 4 min. Our sample consisted of 36 subjects (age range: 18 to 26 years) and each subject performed all blocks. Trials following the presentation of mutilation pictures (283 ms) had significantly slower reaction times than those following neutral (270 ms) pictures. None of the trials in the "pleasant block" (271 ms) was significantly different from those in the "neutral block". The increase in reaction time observed in the unpleasant block may be related in part to the activation of motivational systems leading to an avoidance behavior. The interference effect observed in this study was similar to the pattern previously described for men. Thus, although women may be more emotionally expressive, they were not more reactive to aversive stimuli than men, as measured by emotional interference in a simple reaction time task.

The brain decade in debate: VI. Sensory and motor maps: dynamics and plasticity

This article is an edited transcription of a virtual symposium promoted by the Brazilian Society of Neuroscience and Behavior (SBNeC). Although the dynamics of sensory and motor representations have been one of the most studied features of the central nervous system, the actual mechanisms of brain plasticity that underlie the dynamic nature of sensory and motor maps are not entirely unraveled. Our discussion began with the notion that the processing of sensory information depends on many different cortical areas. Some of them are arranged topographically and others have non-topographic (analytical) properties. Besides a sensory component, every cortical area has an efferent output that can be mapped and can influence motor behavior. Although new behaviors might be related to modifications of the sensory or motor representations in a given cortical area, they can also be the result of the acquired ability to make new associations between specific sensory cues and certain movements, a type of learning known as conditioning motor learning. Many types of learning are directly related to the emotional or cognitive context in which a new behavior is acquired. This has been demonstrated by paradigms in which the receptive field properties of cortical neurons are modified when an animal is engaged in a given discrimination task or when a triggering feature is paired with an aversive stimulus. The role of the cholinergic input from the nucleus basalis to the neocortex was also highlighted as one important component of the circuits responsible for the context-dependent changes that can be induced in cortical maps

The brain decade in debate: III. Neurobiology of emotion

This article is a transcription of an electronic symposium in which active researchers were invited by the Brazilian Society of Neuroscience and Behavior (SBNeC) to discuss the advances of the last decade in the neurobiology of emotion. Four basic questions were debated: 1) What are the most critical issues/questions in the neurobiology of emotion? 2) What do we know for certain about brain processes involved in emotion and what is controversial? 3) What kinds of research are needed to resolve these controversial issues? 4) What is the relationship between learning, memory and emotion? The focus was on the existence of different neural systems for different emotions and the nature of the neural coding for the emotional states. Is emotion the result of the interaction of different brain regions such as the amygdala, the nucleus accumbens, or the periaqueductal gray matter or is it an emergent property of the whole brain neural network? The relationship between unlearned and learned emotions was also discussed. Are the circuits of the former the underpinnings of the latter? It was pointed out that much of what we know about emotions refers to aversively motivated behaviors, like fear and anxiety. Appetitive emotions should attract much interest in the future. The learning and memory relationship with emotions was also discussed in terms of conditioned and unconditioned stimuli, innate and learned fear, contextual cues inducing emotional states, implicit memory and the property of using this term for animal memories. In a general way it could be said that learning modifies the neural circuits through which emotional responses are expressed

The nucleus of the optic tract of the opossum

This paper reviews anatomical and electrophysiological data on the nucleus of the optic tract (NOT) of the opossum, a nucleus in the afferent branch of the horizontal optokinetic reflex. It is proposed that subcortical routes are essential for responses from the two eyes: a direct retinal projection from the contralateral eye and a commissural pathway between the two NOTs for the ipsolateral eye. In the latter case there's evidence that the commisural axons have a relay on inhibitory neurones. This circuit accounts for the differences in response pattern under monocular condition: temporo-nasal motion of the visual stimulus elicits excitation in the contralateral NOT, resulting in inhibition of the ipsolateral nucleus, while naso-temporal motion promotes inhibition in the contralateral nucleus, releasing the ipsolateral nucleus from the commissural input.

NADPH diaphorase histochemistry as a marker for barrels in rat somatosensory cortex

The primary somatosensory area (S1) of rodents presents multicellular units called barrels which can be identified by different techniques (e.g., Nissl staining, cytochrome oxidase or succinate dehydrogenase histochemistry). We applied NADPH diaphorase histochemistry to tangential sections of rat neocortex to determine if the reactive neuropil also shows the same remarkable array observed with other techniques. We demonstrated NADPH diaphorase-positive barrels in all hemispheres tested. The barrels are recognized as patches where the neuropil is most reactive. Each barrel is separated from the other by a less labeled neuropil. Many NADPH diaphorase-positive neurons are seen along the section, but very few cells are found in the barrel fild. In this region, most of the labeled neurons are localized in the less reactive region between the barrels, although a few NADPH diaphorase-positive cells can also be found insede the barrels

Distribution of NADPH-diaphorase-positive neurons in the opossum neocortex

The distribution of NADPH-diaphorase reactive cells was evalutated both in horizontal sections of a flattended cortex and in transversal sections of the opossum (Didelphis marsupialis) neocortex. The tangential distribution of labeled cells behind the orbitalis fissure was denser in the rostral vs caudal regions and in the lateral vs medial regions. Transversal sections revealed that most of the positive neurons are in the grey matter, although 1/4 of this population is located in the underlying white matter. This pattern of neuronal distribution is similar to that previously described in rodents, but quite different from that observed in higher mammals such as the cat and primates

Evidence for recrossing of the pathway from the retina to the ipsilateral nucleus of the optic tract

Single-unit recordings of the nucleous of the optic tract (NOT) under visual stimulation were performed in 5 opossums. Most of the units were directionally selective. Receptive fields for the contralateral eye lie mainly in the contralateral field while those for the ipsilateral eye were mainly in the ipsilateral field. As the nasal does not project ipsilaterally, recrossing must occur in the pathway from the retina to the ipsilateral NOT. Possible sites for this recrossing are discussed

Horizontal optokinetic reflex in the opussum Didelphis marsupialis aurita

Electro-oculographic recordings were performed in 10 opossums. The optokinetic reflex was elicited by projecting a random dot stimulus on a cylindrical screen moving horizontally from left to right or right to left at various constant speeds. Binocular stimulation yelded the same response as the temporal to nasal monocular condition. The nasal to temporal monocular response was always less than to the opposite direction: 50% at 3 degrees/s and 15% at 18 degress/s. These results are discussed in a comparative context