Urethane anaesthesia exhibits neurophysiological correlates of unconsciousness and is distinct from sleep.

Urethane is a general anaesthetic widely used in animal research. The state of urethane anaesthesia is unique because it alternates between macroscopically distinct electrographic states: a slow-wave state that resembles non-rapid eye movement (NREM) sleep and an activated state with features of both REM sleep and wakefulness. Although it is assumed that urethane produces unconsciousness, this has been questioned because of states of cortical activation during drug exposure. Furthermore, the similarities and differences between urethane anaesthesia and physiological sleep are still unclear. In this study, we recorded the electroencephalogram (EEG) and electromyogram in chronically prepared rats during natural sleep-wake states and during urethane anaesthesia. We subsequently analysed the power, coherence, directed connectivity and complexity of brain oscillations and found that EEG under urethane anaesthesia has clear signatures of unconsciousness, with similarities to other general anaesthetics. In addition, the EEG profile under urethane is different in comparison with natural sleep states. These results suggest that consciousness is disrupted during urethane. Furthermore, despite similarities that have led others to conclude that urethane is a model of sleep, the electrocortical traits of depressed and activated states during urethane anaesthesia differ from physiological sleep states.

Power and Coherence in the EEG of the Rat: Impact of Behavioral States, Cortical Area, Lateralization and Light/Dark Phases.

The sleep-wake cycle is constituted by three behavioral states: wakefulness (W), non-REM (NREM) and REM sleep. These states are associated with drastic changes in cognitive capacities, mostly determined by the function of the thalamo-cortical system, whose activity can be examined by means of intra-cranial electroencephalogram (iEEG). With the purpose to study in depth the basal activity of the iEEG in adult rats, we analyzed the spectral power and coherence of the iEEG during W and sleep in the paleocortex (olfactory bulb), and in neocortical areas. We also analyzed the laterality of the signals, as well as the influence of the light and dark phases. We found that the iEEG power and coherence of the whole spectrum were largely affected by behavioral states and highly dependent on the cortical areas recorded. We also determined that there are night/day differences in power and coherence during sleep, but not in W. Finally, we observed that, during REM sleep, intra-hemispheric coherence differs between right and left hemispheres. We conclude that the iEEG dynamics are highly dependent on the cortical area and behavioral states. Moreover, there are light/dark phases disparities in the iEEG during sleep, and intra-hemispheric connectivity differs between both hemispheres during REM sleep.

Violência na intimidade nos relacionamentos homossexuais gays e lésbicos / Violencia en la intimidad en las relaciones homosexuales gays y lesbianas / Intimate violence in gay and lesbian relationships

Resumo O presente estudo teve como objetivo estudar a prevalência da violência na intimidade nos relacionamentos homossexuais, gays e lésbicos. A amostra foi constituída por 48 participantes de nacionalidade portuguesa, com idades compreendidas entre os 18 e os 55 anos (M=26.50; DP=8.011), sendo que 72.9% (n=35) se identificam como lésbicas (sexo feminino) e 27.1% (n=13) se identificam como gay (sexo masculino). As tipologias de violência identificadas com maior prevalência pelas vítimas foram a violência psicológica, seguindo-se a violência física, a violência socioeconômica e a violência sexual. No contexto de perpetração de abuso, as tipologias de violência identificadas com maior prevalência foram a violência psicológica, seguindo-se a violência física e, por fim, com a mesma prevalência, a violência sexual e a violência socioeconômica. Afigura-se necessário um maior investimento na produção de conhecimento científico nesta área.

Resumen El presente estudio tuvo como objetivo estudiar la prevalencia de la violencia en la intimidad en las relaciones homosexuales gays y lesbianas. La muestra del presente estudio está constituida por 48 participantes de nacionalidad portuguesa, con edades comprendidas entre los 18 y los 55 años (M=26.50; DP=8.011), siendo que el 72.9% (n=35) de la muestra se identifica como lesbiana (sexo femenino) y el 27.1% (n=13) se identifica como gay (sexo masculino). Las tipologías de violencia identificadas con mayor prevalencia por las víctimas fueron la violencia psicológica, la violencia física, la violencia socioeconómica y la violencia sexual. En el contexto de perpetración de abuso, las tipologías de violencia identificadas con mayor prevalencia fueron la violencia psicológica, luego la violencia física y, por último, con la misma prevalencia, la violencia sexual y la violencia socioeconómica. Es necesario una mayor inversión en la producción de conocimiento científico en esta área.

Abstract This study aimed to study the prevalence of intimate violence in gay and lesbian relationships. The sample of this study consists of 48 participants of Portuguese nationality, aged between 18 and 55 years (M=26.50; DP=8.011), of which 72.9% (n=35) of the sample is identified as lesbian (female) and 27.1% (n=13) identifies as gay (male). The types of violence identified with the highest prevalence for the victims was psychological violence, followed by physical violence, socio-economic violence and sexual violence. In the context of abuse perpetration, the types of violence identified with the highest prevalence were psychological violence, followed by physical violence and, finally, with the same prevalence, sexual violence and socio-economic violence. There is a need for greater investment in the production of scientific knowledge in this area.