Caracterização do ritmo de atividade/repouso do Mocó (Kerodon Rupestris) em fotoperíodo artificial

Kerodon rupestris (rock cavy, mocó) is an endemic caviidae of Brazilian northeast that inhabits rocky places in the semi arid region. The aim of this study was to characterize the activity/rest rhythm of the rock cavy under 12:12 h LD cycle and continuous light. In the first stage, seven animals were submitted to two light intensities (LD; 250:0 lux and 400:0 lux; 40 days each intensity). In the second stage four males were kept for 40 days in LD (470:<1 lux), for 18 days in LL 470 lux (LL470) and for 23 days in red dim light below 1 lux (LL<1). In the third stage three males were initially kept in LD 12:12 h (450:<1 lux) and after that in LL with gradual increase in light intensity each 21 days (<1 lux LL<1; 10 lux-LL10; 160 lux LL160; 450 lux LL450). In the fourth stage it was analyzed the motor activity of 16 animals in the first 10 days in LD. Motor activity was continuously recorded by passive infrared movement sensors connected to a computer and totaled in 5 min bins. The activity showed circadian and ultradian rhythms and activity peaks at phase transitions. The activity and the rest occurred in the light as well as in the dark phase, with activity mean greater in the light phase for most of the animals. The light intensity influenced the activity/rest rhythm in the first three stages and in the first stage the activity in 400 lux increased in four animals and decreases in two. In the second stage, the tau for 3 animals in LL470 was greater than 24 h; in LL<1 it was greater than 24 h for one and lower for two. In the third stage the tau decreased with the light intensity increase for animal 8. During the first days in the experimental room, the animals did not synchronize to the LD cycle with activity and rest occurring in both phases. The results indicate that the activity/rest rhythm of Kerodon rupestris can be affected by light intensity and that the synchronization to the LD cycle results from entrainment as well as masking probably as a consequence of the action of two or more oscillators with low coupling strength

Global slowing of network oscillations in mouse neocortex by diazepam

SCHEFFZUK, C. , KUKUSHKA, V. , VYSSOTSKI, A. L. , DRAGUHN, A. , TORT, A. B. L. , BRANKACK, J. . Global slowing of network oscillations in mouse neocortex by diazepam. Neuropharmacology , v. 65, p. 123-133, 2013.

Theta-associated high-frequency oscillations (110–160 Hz) in the hippocampus and neocortex

TORT, A. B. L. ; SCHEFFER-TEIXEIRA, R ; Souza, B.C. ; DRAGUHN, A. ; BRANKACK, J. . Theta-associated high-frequency oscillations (110-160 Hz) in the hippocampus and neocortex. Progress in Neurobiology , v. 100, p. 1-14, 2013.

Selective Coupling between Theta Phase and Neocortical Fast Gamma Oscillations during REM-Sleep in Mice

TORT, A. B. L. ; SCHEFFER-TEIXEIRA, R ; Souza, B.C. ; DRAGUHN, A. ; BRANKACK, J. . Theta-associated high-frequency oscillations (110-160 Hz) in the hippocampus and neocortex. Progress in Neurobiology , v. 100, p. 1-14, 2013.

A rotina de crianças de zero a dois anos na educação infantil e as especificidades infantis

In current upbringing production, children are often conceived as rightful subjects, and concrete and singular people, marked by specificities that schools must respect, mainly their personal wholeness, their care and attention needs, as well as their abilities to learn and produce culture. In the educational practices frame, routine is considered to have a definitive roll in time, space and activities structuring, as with actions and relations of subjects involved. In that perspective, this research aims to analyze routines of zero to two years old children in the upbringing context, relating to their childish specificities. Anchored in the qualitative approach, a Case Study was developed, according the procedures of daily routine observation and semi-structured interviews with six nursery teachers of CMEI Centro Municipal de Educação Infantil, Natal-RN, the research field. The data analysis was based in Speech Analysis principles. The teachers utterances regarding routine and it s roll in the frame revealed significances related to control/regulation of actions theirs and students aiming to streamline tasks; learning relative to routine itself, time and school practices. Thus, prospects of discipline and exercise of power of teachers over students surges, reducing their possibilities to participate. These conceptions reflect the daily routine of the kids and their teachers. By analyzing the methods of routine operation in the time/space/activities frame of CMEI, it was possible to perceive its homogenization of actions and rhythms, not only of the group s children, but the whole institution, which creates, many times, a controlling character that contains/prevents children s initiative. However, it was also possible to observe that in routine recesses, when it s relaxed, and other spaces, times and actions are provided, kids have the opportunity to experience and create different ways of action and relation with time, materials, other kids and teachers, being, as such, respected their specificities. We highlight the importance of reflections regarding routine in upbringing context, as to comprehend it s functions and the need for it s construction to take a multiple character that respects the plurality of situations and singularities of children as persons

Versão breve da social rhythm metric: um instrumento para avaliar ritmo social de pacientes com acidente vascular cerebral

Stroke is a neurological disorder caused by restriction of blood flow to the brain, which generates directly a deficit of functionality that affects the quality of life of patients. The aim of this study was to establish a short version of the Social Rhythm Scale (SRM), to assess the social rhythm of stroke patients. The sample consisted of 84 patients, of both sexes, with injury time exceeding 6 months. For seven days, patients recorded the time held 17 activities of SRM. Data analysis was performed using a principal components factor analysis with varimax rotation of the full version of SRM in order to determine which activities could compose brief versions of SRM. We then carried out a comparison of hits, the ALI (Level Activity Index) and SRM, between versions, by Kruskal-Walls and the Mann-Whitney test. The Spearman correlation test was used to evaluate the correlation between the score of the full version of SRM with short versions. It was found that the activities of SRM were distributed in three versions: the first and second with 6 activities and third with 3 activities. Regarding hits, it was found that they ranged from 4.9 to 5.8 on the first version; 2.3 to 3.8 in version 2 and 2.8 to 6.2 in version 3, the first the only version that did not show low values. The analysis of ALI, in version 1, the median was 29, in version 2 was 14 and in version 3 was 18. Significant difference in the values of ALI between versions 1 and 2, between 2 and 3 and between versions 1 and 3. The highest median was found in the first version, formed by activities: out of bed, first contact, drink coffee, watch TV in the evening and go to bed. The lowest median was observed in the second version and this was not what had fewer activities, but which had social activities. The medians of the SRM version 1 was 6, version 2 was 4 and version 3 was 6. Significant difference in the values of SRM between versions 1 and 2 and between 2 and 3, but no significant difference between versions 1 and 3. Through analysis, we found a significant correlation only between the full version and the version 1 (R2 = 0.61) (p <0.05), no correlation was found with version 2 (R2 = 0.007) nor with version 3 (R2 = 0.002), this was finally a factor to consider version 1 as the short brazilian version of the Social Rhythm Metric for stroke patients

Caracterização dos acoplamentos fase-amplitude na região CA1 do hopocampo

Brain oscillation are not completely independent, but able to interact with each other through cross-frequency coupling (CFC) in at least four different ways: power-to-power, phase-to-phase, phase-to-frequency and phase-to-power. Recent evidence suggests that not only the rhythms per se, but also their interactions are involved in the execution of cognitive tasks, mainly those requiring selective attention, information flow and memory consolidation. It was recently proposed that fast gamma oscillations (60 150 Hz) convey spatial information from the medial entorhinal cortex to the CA1 region of the hippocampus by means of theta (4-12 Hz) phase coupling. Despite these findings, however, little is known about general characteristics of CFCs in several brain regions. In this work we recorded local field potentials using multielectrode arrays aimed at the CA1 region of the dorsal hippocampus for chronic recording. Cross-frequency coupling was evaluated by using comodulogram analysis, a CFC tool recently developted (Tort et al. 2008, Tort et al. 2010). All data analyses were performed using MATLAB (MathWorks Inc). Here we describe two functionally distinct oscillations within the fast gamma frequency range, both coupled to the theta rhythm during active exploration and REM sleep: an oscillation with peak activity at ~80 Hz, and a faster oscillation centered at ~140 Hz. The two oscillations are differentially modulated by the phase of theta depending on the CA1 layer; theta-80 Hz coupling is strongest at stratum lacunosum-moleculare, while theta-140 Hz coupling is strongest at stratum oriens-alveus. This laminar profile suggests that the ~80 Hz oscillation originates from entorhinal cortex inputs to deeper CA1 layers, while the ~140 Hz oscillation reflects CA1 activity in superficial layers. We further show that the ~140 Hz oscillation differs from sharp-wave associated ripple oscillations in several key characteristics. Our results demonstrate the existence of novel theta-associated high-frequency oscillations, and suggest a redefinition of fast gamma oscillations

"O núcleo supraquiasmático e o folheto intergeniculado do mocó (Kerodon rupestris): Projeções retinianas e caracterização imuno-histoquímica

In this study, two circadian related centres, the suprachiasmatic nucleus (SCN) and the intergeniculate leaflet (IGL) were evaluated in respect to their cytoarchitecture, retinal afferents and chemical content of major cells and axon terminals with a tract tracer and immunohistochemical techniques in the rock cavy (Kerodon rupestris), a Brazilian caviidae rodent species. The rock cavy SCN is innervated in its ventral portion by terminals from the predominantly contralateral retina. It also contains neurophisin and vasoactive intestinal polypeptide immunoreactive cell bodies and neuropeptide Y and enkephalin immunopositive fibres and terminals and is marked by intense GFAP immunoreactivity. The IGL receives a predominantly contralateral retinal projection, contains neuropeptide Y and nitric oxide synthase producing neurons and enkephalin immunopositive terminals and is characterized by dense GFAP immunoreactivity. This is the first report examining the neural circadian system in a crepuscular rodent species for which circadian properties have been described. The results are discussed comparing with what has been described for other species and in the context of the functional significance of these centres

Saguis (Callithrix jacchus) sob ciclo claro-escuro de 21 h: um modelo de dessincronização forçada em primata diurno

The circadian system consists of multiple oscillators organized hierarchically, with the suprachiasmatic nucleus (SCN) as the master oscillator to mammalians. There are lots of evidences that each SCN cell is an oscillator and that entrainment depends upon coupling degree between them. Knowledge of the mechanism of coupling between the SCN cells is essential for understanding entrainment and expression of circadian rhythms, and thus promote the development of new treatments for circadian rhythmicity disorders, which may cause various diseases. Some authors suggest that the dissociation model of circadian rhythm activity of rats under T22, period near the limit of synchronization, is a good model to induce internal desynchronization, and in this way, enhance knowledge about the coupling mechanism. So, in order to evaluate the pattern of the motor activity circadian rhythm of marmosets, Callithrix jacchus, in light-dark cycles at the lower limit of entrainment, two experiments were conducted: 1) 6 adult females were submitted to the LD symmetric cycles T21, T22 and T21.5 for 60, 35 and 48 days, respectively; 2) 4 male and 4 female adults were subjected to T21 for 24 days followed by 18 days of LL, and then back to T21 for 24 days followed by 14 days of LL. Vocalizations of all animals and motor activity of each one of them were continuously recorded throughout the experiments, but the vocalizations were recorded only in Experiment 1. Under the Ts shorter than 24 h, two simultaneous circadian components appeared in motor activity, one with the same period of LD cycle, named light-entrained component, and the other in free-running, named non-light-entrained component. Both components were displayed for all the animals in T21, five animals (83.3%) in T21.5 and two animals (33.3%) in T22. For vocalizations both components were observed under the three Ts. Due to the different characteristics of these components we suggest that dissociation is result of partial synchronization to the LD cycle, wherein at least one group oscillator is synchronized to the LD by relative coordination and masking processes, while at least another group of oscillators is in free-running, but also under the influence of masking by the LD. As the T21 h was the only cycle able to promote the emergence of both circadian components in circadian rhythms of all Callithrix jacchus, this was then considered the lower entrainment limit of LD cycle promoter of dissociation in circadian rhythmicity of this species, and then suggested as a non-human primate model for forced desynchronization

Estudo da organização funcional do sistema circadiano por meio de ferramentas computacionais e matemáticas

Circadian rhythms are variations in physiological processes that help living beings to adapt to environmental cycles. These rhythms are generated and are synchronized to the dark light cycle through the suprachiasmatic nucleus. The integrity of circadian rhythmicity has great implication on human health. Currently it is known that disturbances in circadian rhythms are related to some problems of today such as obesity, propensity for certain types of cancer and mental disorders for example. The circadian rhythmicity can be studied through experiments with animal models and in humans directly. In this work we use computational models to gather experimental results from the literature and explain the results of our laboratory. Another focus of this study was to analyze data rhythms of activity and rest obtained experimentally. Here we made a review on the use of variables used to analyze these data and finally propose an update on how to calculate these variables. Our models were able to reproduce the main experimental results in the literature and provided explanations for the results of experiments performed in our laboratory. The new variables used to analyze the rhythm of activity and rest in humans were more efficient to describe the fragmentation and synchronization of this rhythm. Therefore, the work contributed improving existing tools for the study of circadian rhythms in mammals

Avaliação comportamental e neuroquímica de ratos em dessincronização forçada: possíveis implicações para um modelo animal de oscilações no humor

Bipolar disorder has been growing in several countries. It is a disease with high mortality and has been responsible by the social isolation of the patients. Bipolar patients have alterations in circadian timing system, showing a phase shift in various physiological variables. There are several arguments demonstrating alterations in circadian rhythms may be part of the bipolar disorder pathophysiology. Given the necessity for further elucidation, the goal of this study was to validate the forced desynchronization protocol as an animal model for bipolar disorder. To do this, Wistar rats were submitted to a forced desynchronization protocol which consists in a symmetrical light dark cycle with 22h. Under this protocol, rats dissociate the locomotor activity rhythm into two components: one synchronized to the light / dark cycle with 22h, and another component with period longer than 24 hours following the animal endogenous period. These rhythms with different periods sometimes there is coincidence, which we named CAP (Coincidence Active Phase) and the opposite phase, non-coincidence, called NCAP (Non-Concidence Active Phase). The hypothesis is that in CAP animals present a mania-like behavior and animals in NCAP depressive-like behavior. We found some evidence described in detail throughout this thesis. In sum, the animals under forced desynchronization protocol were more stressed, showed an increase in stereotypic behaviors such as grooming and reduction in other behaviors such as risk assessment and vertical exploration when compared to the control group. The CAP animals showed increased locomotor activity, especially during the dark phase when compared to controls (rats under T24) and less depressive behavior in the forced swim test. The animals in NCAP showed a higher anxiety in elevated plus maze, but they don t have ahnedonia. The animals under dissociation have more labeled 5HT1A cells at the amygdala area, which appoint that they have more amygdala inhibition. Taking these data together, we could partially validated the forced desynchronization protocol as an animal model for mood oscillations

O trato retino-hipotalâmico no mocó (Kerodon rupestris): Um estudo de traçado anterógrado com a subunidade b da toxina colérica

The light, besides the vision stimuli, controls other process completely independent of image formation, such as the synchronization of the organismic circadian rhythms to the enviromental light/dark cycle. In mammals, this adjust occurs through the retinohypothalamic tract, a direct retinal projection to the suprachiasmatic nucleus, considered to be the major circadian pacemaker. Early studies have identified only the suprachiasmatic nucleus as a retinal target in the hypothalamus. However, using more sensitive neuroanatomic tracers, other retinorecipient hypothalamic regions outside to suprachiasmatic nucleus were pointed in a great number of mammalian species. In this study, the retinohypothalamic tract was shown in the rock cavy (Kerodon rupestris), an endemic rodent of the semiarid region of the Brazilian Northeast, using unilateral intravitreal injections of cholera toxin subunit b as a neuronal tracer. The results reveal that in the rock cavy, besides the suprachiasmatic nucleus, several hypothalamic regions receive direct retinal projection, such as the ventrolateral preoptic nucleus, medial and lateral preoptic areas, the supraoptic nucleus and bordering areas, anterior, lateral and rectrochiasmatic hypothalamic areas, and the subparaventricular zone. The results are discussed by comparing with those of the literature, into a functional context

Caracterização do ritmo de atividade motora durante a puberdade em sagüis (Callithrix jacchus) sob condições semi-naturais

Most of ontogenetic studies on circadian timing system have been developed on infants, adults and elderly. The puberty has not been a stage of life few studied, except for researches in human adolescents, that presents phase delay in sleep-wake cycle. However, few studies have focused on the basis of this circadian change due to methodological difficulties. Thus, an animal model to study the sleep-wake cycle at puberty is essential. In the common marmoset, a social primate, the circadian activity periodicity stabilizes around 4 months (juvenile stage) and the 8h period component has a seasonal variation. Puberty stage of this species begins near the 8th month of age in males and near the 7th month in females with 7 months of duration. With the aim to characterize the circadian motor activity rhythm during puberty in marmosets (Callithrix jacchus) the motor activity was continuous registered by actiwatches in 6 animals between 5-12 months. Since the social factor influence the behavior of this specie, behavioral observations were realized in 30 minutes windows twice/week to a general evaluation of the influence social interactions dynamic across experiment. Determination of puberty onset was done by fecal progesterone and estrogens in females, and androgens in males. From the analysis of the multiple regression test was selected a model that evaluate age and seasonal variables effect on the activity rhythm according to the higher explanation coefficient. The total activity was the only parameter influenced by age. Moreover, the activity onset was the parameter more explained by the model, and the sunrise was the factor that most influenced it. After the puberty onset, 2 dyads advanced the activity onset. The activity total decreased in 1 dyad and increased in 2 dyads. This increase may be related to the birth of infants in these families. The motor activity circadian component stabilized later in 1 dyad, coinciding with the puberty onset of these animals, while bimodality, caused by the 8 h component, was modulated by seasonality. The agonistic behavior was not evaluated due to reduced number of events. There were changes across ages in affiliative behavior of contact in 1 dyad, grooming done in 1 animal and grooming received in 2 animals. Although there is evidence of puberty effect on the activity motor rhythm, the photoperiodic fluctuations influenced the rhythm. Therefore is not possible to affirm if the puberty modulate the activity rhythm in marmosets

Caracaterização do núcleo pré-geniculado do sagüi (Callithrix jacchus) :projeção retiniana, neuroquímica e atividade celular (expressão de FOS)

In rodents, the suprachiasmatic nucleus (SCN) and the intergeniculate leaflet (IGL) are the main components of the circadian system. The SCN is considerate the site of an endogenous biological clock because can to generate rhythm and to synchronize to the environmental cues (zeitgebers) and IGL has been related as one of the main areas that modulate the action of SCN. Both receive projections of ganglion cells of retina and this projection to SCN is called retinohypothalamic tract (RHT). Moreover, the IGL is connected with SCN through of geniculohypothalamic tract (GHT). In primates (include humans) was not still demonstrated the presence of a homologous structure to the IGL. It is believed that the pregeniculate nucleus (PGN) can be the answer, but nothing it was still proven. Trying to answer that question, the objective of our study is to do a comparative analysis among PGN and IGL through of techniques immunohystochemicals, neural tracers and FOS expression after dark pulses. For this, we used as experimental model a primate of the new world, the common marmoset (Callithrix jacchus). Ours results may contribute to the elucidation of this lacuna in the circadian system once that the IGL is responsible for the transmission of nonphotic information to SCN and participate in the integration between photic and nonphotic stimulus to adjust the function of the SCN. In this way to find a same structure in primates represent an important achieve in the understanding of the biological rhythms in those animals

Sincronização dos ritmos de atividade motora e temperatura central à disponibilidade de glicose em ratos

Food is essential for the survival of all animals. Its temporal availability is an important enviromental cue for the behavioral and physiological organization throughout the 24 hours of day in different species. Rats and mice, for example, show increased locomotion in the hours before food availability when it is presented in a recurrent manner, a behavior named foodanticipatory activity. Several lines of evidence indicate that this anticipation is mediated by a circadian oscillator. In this work, based on the hypothesis that pre- or post-ingestive humoral signals are involved in the entrainment process, we tested whether the daily intake of glucose is sufficient to induce anticipatory activity in rats. The rhythms of motor activity and central temperature were recorded in animals undergoing 10 days of temporal glucose (solution at 50%) or chow restriction in light-dark (LD) and constant darkness (DD). Animals under temporal glucose restriction increase motor activity and and central temperature in the hours preceding glucose availability and such aticipation is extremely similar to that observed in animals under temporal chow restriction. Glucose ingestion is, therefore, a sufficient temporal cue to induce anticipation in rats. It is possible that the increase in plasma glucose after food ingestion constitutes one of the signals involved in the behavioral entrainment process to food availability