Influência de fotoperíodo artificial no comportamento de um primata neotropical diurno (Callithrix jacchus)

One of the main environmental cues for the adjustment of temporal organization of the animals is the light-dark cycle (LD), which undergoes changes in phase duration throughout the seasons. Photoperiod signaling by melatonin in mammals allows behavioral changes along the year, as in the activity-rest cycle, in mood states and in cognitive performance. The aim of this study was to investigate if common marmoset (Callithrix jacchus) exhibits behavioral changes under short and long photoperiods in a 24h cycle, assessing their individual behaviors, vocal repertoire, exploratory activity (EA), recognition memory (RM) and the circadian rhythm of locomotor activity (CRA). Eight adult marmosets were exposed to a light-dark cycle of 12:12; LD 08:16; LD 12:12 and LD 16:08, sequentially, for four weeks in each condition. Locomotor activity was recorded 24h/day by passive infrared motion detectors above the individual cages. A video camera system was programmed to record each animal, twice a week, on the first two light hours. From the videos, frequency of behaviors was registered as anxiety-like, grooming, alert, hanging position, staying in nest box and feeding using continuous focal animal sampling method. Simultaneously, the calls emitted in the experimental room were recorded by a single microphone centrally located and categorized as affiliative (whirr, chirp), contact (phee), long distance (loud shrill), agonistic (twitter) and alarm (tsik, seep, see). EA was assessed on the third hour after lights onset on the last week of each condition. In a first session, marmosets were exposed to one unfamiliar object during 15 min and 24h later, on the second session, a novel object was added to evaluate RM. Results showed that long days caused a decreased of amplitude and period variance of the CRA, but not short days. Short days decreased the total daily activity and active phase duration. On long days, active phase duration increased due to an advance of activity onset in relation to symmetric days. However, not all subjects started the activity earlier on long days. The activity offset was similar to symmetric days for the majority of marmosets. Results of EA showed that RM was not affected by short or long days, and that the marmosets exhibited a decreased in duration of EA on long days. Frequency and type of calls and frequency of anxiety-like behaviors, staying in nest box and grooming were lower on the first two light hours on long days. Considering the whole active phase of marmosets as we elucidate the results of vocalizations and behaviors, it is possible that these changes in the first two light hours are due to the shifting of temporal distribution of marmoset activities, since some animals did not advance the activity onset on long days. Consequently, the marmosets mean decreased because the sampling was not possible. In conclusion, marmosets synchronized the CRA to the tested photoperiods and as the phase angle varied a lot among marmosets it is suggested that they can use different strategies. Also, long days had an effect on activity-rest cycle and exploratory behaviors

Influência da auto seleção à luz no ritmo circadiano de atividade motora em Callithrix Jacchus

Marmosets, Callithrix jacchus, are strictly diurnal animals. The motor activity rhythmicity is generated by the circadian timing system and is modulated by environmental factors, mainly by photic stimuli that compose the light-dark cycle. Photic stimuli can reset the biological oscilators changing activity motor pattern, by a mechanism called entrainment. Otherwise, light can act directly on expressed rhythm, without act on the biological oscillators, promoting the masking. Thus, photic stimuli can synchronize the circadian activity rhythm (CAR) by two distinct mechanisms, acting isolated or at a combined way. Among the elements that can influence photic synchronization, the duration and time of photic exposure is pointed out. If in the natural environment the marmoset can choose places of different intensity illumination and is synchronized to light-dark cycle (LD), how the photic synchronization mechanism can be evaluated in laboratory by light self-selection? With objective to response this question, four adult male marmosets were studied at two conditions: with and without sleeping box. The animals were submitted to a LD cycle (12:12/ 350:2 lx) and constant light (LL: 350 lx) conditions in individual cages with an opaque sleeping box, that permitted the light self-selection. At the room, the temperature was 25.6 ºC (± 0.3 ºC) and humidity was 78.7 (± 5%). The motor activity was recorded at 5 min bins by infrared movement sensors installed at the top of the cages. The motor activity profile was distinct at the two conditions: without the sleeping box protection against light, the activity frequency was higher at CT 11-12 (ANOVA; F(3.23) = 62.27; p < 0.01). Also, the duration of the active phase (α) was prolonged of about 1 h (t test, p < 0.05) and the animals showed a significant delay on the activity onset and offset (t test, p < 0.05) and at the acrophase (confidence intervals of 5%) of CAR. In LL, the light continuous exposure prolonged the active phase and influenced the endogenous expression of the circadian activity rhythm period. From the result analysis, it is concluded that the light self-selection can modify several parameters of CAR in marmosets, allowing the study of the synchronization mechanism using the burrow model. Thus, without sleeping box there was a phase delay between the CAR and LD (entrainment) and an increase of activity near lights off (positive masking). Furthermore, in LL, the light continuous exposure modifies α and the endogenous expression of CAR. It is suggested that the light self-selection might be take into account at investigations that evaluate the biological rhythmicity in marmosets

Caracterização do perfil do ciclo sono-vigília em ratos sob dessincronização forçada

The circadian behavior associated with the 24 hours light-dark (LD) cycle (T24) is due to a circadian clock , which in mammals is located in the hypothalamic suprachiasmatic nucleus (SCN). Under experimental conditions in which rats are espoused to a symmetric LD 22h cycle (T22) the two SCN regions, ventrolateral (vl) and dorsomedial (dm), can be functionally isolated, suggesting that each region regulates distinct physiological and behavioral components. The vl region regulates the locomotor activity and slow wave sleep (SWS) rhythms, while the dm region assures the body temperature and paradoxical sleep (PS) rhythms regulation. This research aimed to deepen the knowledge on the functional properties of circadian rhythmicity, specifically about the internal desynchronization process, and its consequences to locomotor activity and body temperature rhythms as well as to the sleep-wake cycle pattern in rats. We applied infrared motion sensors, implanted body temperature sensors and a telemetry system to record electrocorticogram (ECoG) and electromyogram (EMG) in two rat groups. The control group under 24h period LD cycle (T24: 12hL-12hD) to the baseline record and the experimental group under 22h period LD cycle (T22: 11hL- 11hD), in which is known to occur the uncoupling process of the circadian locomotor activity rhythm where the animals show two distinct locomotor activity rhythms: one synchronized to the external LD cycle, and another expressed in free running course, with period greater than 24h. As a result of 22h cycles, characteristic locomotor activity moment appear, that are coincidence moments (T22C) and non coincidence moments (T22NC) which were the main focus or our study. Our results show an increase in locomotor activity, especially in coincidence moments, and the inversion of locomotor activity, body temperature, and sleep-wake cycle patterns in non coincidence moments. We can also observe the increase in SWS and decrease in PS, both in coincidence and non coincidence moments. Probably the increases in locomotor activity as a way to promote the coupling between circadian oscillators generate an increased homeostatic pressure and thus increase SWS, promoting the decreasing in PS

A cafeína como agente modulador do ciclo atividade-repouso e memória em saguis (Callithrix jacchus)

Caffeine is the most consumed psychostimulant, with effects on attention, memory, and arousal. But when this substance is ingested near to bedtime there is a decrease on sleep, interfering on mnemonic processes. So, our ain was to investigate how the caffeine ingested near to sleep onset acts on sleep and memory in marmosets. We used 16 adult marmosets, single housed, in a 12:12h light-dark cycle. For registering locomotor activity were used two kinds of sensors. The gyroscope sensor registers activity each 30 sec and detects motion with good accuracy. Because of this we used this sensor for detecting nocturnal activity. The second sensor was based on infrared and accumulates activity each 5 min and it’s not able to detect nocturnal activity, just diurnal activity. We also used camera for registering Rest phase of one marmoset. For the cognitive task, the animals needed to learn a rewarded context (CR) when compared to a non-rewarded context CNR). This experiment comprises 5 phases: 1) Two days of habituation to apparatus; 2)Training for 8 days; 3) oral administration of caffeine (10 mg/kg) or placebo administration ±1h before sleep onset, for 8 days, with marmosets receiving placebo or caffeine; 4) retraining to apparatus and after that, placebo administration (placebo group-GP), or caffeine administration (with continuous group-GC and acute groupGA); 5) Test, for evaluating learning to CR. The sessions were filmed and each one had 8 min of duration. At 7 am started the habituation, training and test sessions, and at 3:15 pm started retraining. The results for gyroscope sensor showed that there was coincidence of 68,57% with nocturnal register of the cameras. Then, the gyroscope sensors detected nocturnal activity for all experimental groups Moreover, when compared sensor gyroscope with sensor based on infrared, was observed that both sensor presented similarity on patterns of activity curve. When we observed the effects of caffeine on Activity-Rest Cycle in GP, GA and GC, is possible to see that that gyroscope sensors and based on infrared presented only intra group differences. As behavioral results, the marmosets learned to discriminate CR when compared to CNR. Moreover, GP presented deficits on memory recall during the test, and GA increased the memory recall, when both were compared to GP. We concluded that the marmosets were able to learning the cognitive task and that the caffeine ingested near to sleep onset acts modulating memory in these animals. Moreover the gyroscope sensor can be used as alternative tool for investigating nocturnal activity. Then, the utilization of this non-invasive device allows marmosets exhibit their behavior within the laboratory conditions as natural as possible.

Mecanismos de sincronia social no ritmo circadiano de atividade durante a coabitação em casais de saguis (Callithrix jacchus)

In marmosets, it was observed that the synchrony among circadian activity profiles of animals that cohabite in family groups is stronger than those of the same sex and age of different families. Inside the group, it is stronger between the younger ones than between them and their parents. However, the mechanisms involved in the social synchrony are unknown. With the aim to investigate the synchronization mechanisms involved in the synchrony between the circadian activity profiles during cohabitation in pairs of marmosets, the motor activity was continuously registered by the use of actmeters on three dyads. The pairs were maintained in two different conditions of illumination: light-dark cycle LD 12:12 (LD cohabitation I – 21 days), and thereafter in LL (~350 lux). Under LL, the pairs were submitted to four experimental situations: 1. Cohabitation (LLJ I – 24 days), 2. Removal of one member of the pair to another room with similar conditions (LLS I – 20 days), 3. Reintroduction of the separated member in the cage of the first situation (LLJ II – 30 days) and 4. Removal of a member from each pair to another experimental room (LLS II – 7 days), to evaluate the mechanisms of synchronization. Ultimately, the members of each pair were reintroduced in the cage and were kept in LD cycle 12:12 (LDJ II – 11 days). The rhythms of pairs free-ran in LL, with identical periods between the members of each pair during the two stages of cohabitation. In the stages in which the animals were separated, only the rhythms of two females free-ran in the first stage and of three animals in the second one. In those conditions, the rhythms of animals of each pair showed different endogenous periods. Besides, during cohabitation in LD and LL, the members of each pair showed a stable phase relationship in the beginning of the active phase, while in the stages in which the animals were separated it was noticed a breaking in the stability in the phase relationships between the circadian activity profiles, with an increase in the difference in the phase angles between them. During cohabitation, at the transition between LD and LL, all animals showed free-running rhythms anticipating progressively the beginning and the end of the active phase in a phase similar to the previous condition, showing signs of entrainment to the previous LD. While in the posterior stages this was observed in only three animals between: LLT I and LLS I, and LLT II and LLS II, evidencing signs of entrainment to social cues between the members of each pair. On the other hand, one animal delayed progressively between LLT I and LLS I, three animals delayed between LLS I and LLT II, and three animals between LLT II and LLS II, perhaps by entrainment to the animals maintained outdoors in the colony. Similar process was observed in four animals between LLS II and LDT II, indicating entrainment to LD. In the transition between LLS I and LLT II, signs of masking was observed in the rhythm of a female in response to the male and in another pair in the rhythm of the male in regard to that of the female. The general and maximum correlations in the circadian activity profiles were stronger during cohabitation in LD and LL than in the absence of social contact in LL, evidencing the social effect. The cohabiting pairs had higher values of the maximum correlation in LD and LL than when the profiles were correlated to animals of different cages, with same or different sexes. Similar results were observed in the general correlation. Therefore, it is suggested that cohabitation induces a strong synchrony between circadian activity profiles in marmosets, which involves entrainment and masking. Nevertheless, additional studies are necessary to evaluate the effect of social cues on the synchronization of the circadian rhythm in pairs of marmosets in the absence of external social cues in order to confirm this hypothesis.

Aprendizagem espaço-temporal e efeitos das condições luminosas no aprendizado do peixe paulistinha

Para processar a informação ambiental e perceber o tempo, os indivíduos utilizam-se de pistas ambientais, como luz e temperatura, que servem como guias para o relógio interno. O mecanismo temporizador endógeno é chamado relógio circadiano, o qual comanda uma grande variedade de ritmos diários bioquímicos, fisiológicos e comportamentais presentes nos organismos. Com isso, os animais podem antecipar eventos espaço-temporalmente distribuídos e usar essa informação para organizar as atividades diárias, o que é uma vantagem adaptativa para os indivíduos, já que muitos fatores ambientais apresentam variação circadiana. Aprendizagem espaço-temporal (do inglês: "time-place learning’’-TPL) é a habilidade de associar lugares com importantes eventos biológicos em diferentes horas do dia. Em nosso estudo utilizamos como modelo o peixe paulistinha (Danio rerio), conhecido por ser altamente social, para testar aprendizagem espaço-temporal baseada em reforço social. Além disso, objetivamos averiguar os efeitos das condições de claro constante e escuro constante na aprendizagem espaço-temporal, e se nessas condições, a atividade do peixe paulistinha é alterada. Para isso, testamos três diferentes condições (n=10): grupo claro-escuro (CE), grupo claro constante (CC) e grupo escuro constante (EE) durante 30 dias da seguinte maneira: diariamente, um grupo de 5 peixes paulistinha foi introduzido em um recipiente localizado no compartimento da manhã (um dos lados do aquário), às 8:00h e retirado às 9:00h, e em outro recipiente do compartimento da tarde (lado oposto do aquário), às 17:00h e removido às 18:00h, servindo como estímulo para que o peixe experimental ocupasse o compartimento onde o grupo fosse colocado. O comportamento foi filmado nos dois horários, 15 minutos antes e durante os 60 minutos de exposição ao estímulo, no 15º e no 30ª dia, porém neste último, os peixes foram filmados sem a presença do estímulo a fim de averiguarmos a aprendizagem espaço-temporal. Por fim, para saber a influência das três condições luminosas na atividade dos peixes, filmamos os últimos 6 dias de teste, para registrar o padrão de atividade. Nossos resultados mostraram que em ciclo claro-escuro (CE) o peixe paulistinha apresenta TPL, bem como é capaz de antecipar a hora e local do estímulo (grupo de coespecíficos), enfatizando a importância do estímulo social para a aprendizagem. Em condições de claro constante e escuro constante, o peixe paulistinha não apresentou aprendizagem espaço-temporal. Ademais, após 30 dias em condições luminosas constantes (claro constante e escuro constante), o peixe paulistinha mantém ritmo circadiano, porém em claro constante sua atividade é aumentada e seu ritmo atividade-repouso é alterado, através de um padrão de atividade distribuída homogeneamente ao longo das 24h, ao invés de concentrada na subjetiva fase clara, como nos grupos de ciclo claro-escuro e escuro constante, os quais conservam o padrão de atividade diurno da espécie.

Preferência alimentar e identificação das principais fontes de repasto sanguíneo de fêmeas Lutzomyia (Diptera: Psychodidae) em áreas endêmicas para leishmaniose visceral na grande Natal

Leishmaniasis are endemic diseases wild spread in the New and Old World, caused by the flagelated protozoan Leishmania. In the New World, the distribution of different forms of leishmaniasis is mostly in tropical regions. In the State of Rio Grande do Norte, Northeast Brazil, 85% of the captured sand flies fauna is Lutzomyia longipalpis. The distribution of the sand fly vector in the state overlaps with the disease distribution, where the presence of sand flies is associated with presence of animals shelters. The aim of this study was to analyse the blood meal preference of sand flies vector from the genus Lutzomyia spp. in laboratory conditions, to verify the vector life cicle at different temperatures sets and to identify the main blood meal source in endemic areas for visceral leishmaniasis (VL) at peri-urban regions of Natal. Sand flies samples were collected from the municipalities of São Gonçalo do Amarante and Nísia Floresta where female sand flies were grouped for the colony maintenance in the laboratory and for the analysis of the preferred source of sand fly blood meal in natural environment. The prevalence of blood meal preference and oviposition for the females sand flies was 97% for Cavia porcellus with oviposition of 19 eggs/female; 97% for Eqqus caballus with 19 eggs/female; 98% for human blood with 14 eggs/female; 71.3% for Didelphis albiventris with 8.4 eggs/female; 73% for Gallus gallus with 14 eggs/female; 86% for Canis familiaris with 10.3 eggs/female; 81.4% for Galea spixii with 26 eggs/female; 36% for Callithrix jachus with 15 eggs/female; 42.8% for Monodelphis domestica with 0% of oviposition. Female sand flies did not take a blood meal from Felis catus. Sand flies life cycle ranged from 32-40 days, with 21-50 oviposition rates approximately. This study also showed that at 32°C the life cycle had 31 days, at 28° C it had 50 days and at 22°C it increased to 79 days. Adjusting the temperature to 35°C the eggs did not hatch, thus blocking the life cycle. A total of 1540 sand flies were captured, among them, 1.310 were male and 230 were female. Whereas 86% of the sand flies captured were Lu. longipalpis as compared to 10.5% for Lu. evandroi and, 3.2% for L. lenti and 0.3% for Lu whitmani. The ratio between female and male sandfly was approximately 6 males to 1 female. In Nísia Floresta, 50.7% of the collected females took their blood meal from armadillo, 12.8% from human. Among the female sand flies captured in São Gonçalo do Amarante, 80 of them were tested for the Leishmania KDNA infectivity where 5% of them were infected with Leishmania chagasi. Female Lutzomyia spp. showed to have an opportunistic blood meal characteristic. The behavioral parameters seem to have a higher influence in the oviposition when compared to the level of total proteins detected in the host s bloodstream. A higher Lu. longipalpis life cycle viability was observed at 28°C. The increase of temperature dropped the life cycle time, which means that the life cycle is modified by temperature range, source of blood meal and humidity. Lu longipalpis was the most specie found in the inner and peridomiciliar environment. In Nísia Floresta, armadillos were the main source of blood meal for Lutzomyia spp. At São Gonçalo do Amarante, humans were the main source of blood meal due to CDC nets placed inside their houses

Investigação do papel modulador do Haloperidol sobre os níveis de proteínas relacionadas à plasticidade e preferência por objetos novos em camudongos

Dopamine (DA) is known to regulate both sleep and memory formations, while sleep plays a critical role in the consolidation of different types of memories. We believe that pharmacological manipulation of dopaminergic pathways might disrupt the sleep-wake cycle, leading to mnemonic deficits, which can be observed in both behavioral and molecular levels. Therefore, here we investigated how systemic injections of haloperidol (0.3 mg/kg), immediately after training in dark and light periods, affects learning assessed in the novel object preference test (NOPT) in mice. We also investigated the hippocampal levels of the plasticity-related proteins Zif-268, brain-derived neurotrophic factor (BDNF) and phosphorylated Ca2+/calmodulin-dependent protein kinases II (CaMKII-P) in non-exposed (naïve), vehicle-injected controls and haloperidol-treated mice at 3, 6 and 12 hours after training in the light period. Haloperidol administration during the light period led to a subsequent impairment in the NOPT. In contrast, preference was not observed during the dark period neither in mice injected with haloperidol, nor in vehicle-injected animals. A partial increase of CaMKII-P in the hippocampal field CA3 of vehicle-injected mice was detected at 3h. Haloperidol-treated mice showed a significant decrease in the dentate gyrus of CaMKII-P levels at 3, 6 and 12h; of Zif-268 levels at 6h, and of BDNF levels at 12h after training. Since the mnemonic effects of haloperidol were only observed in the light period when animals tend to sleep, we suggest that these effects are related to REM sleep disruption after haloperidol injection

Pelo escuro: a poesia afro-brasileira de Oliveira Silveira

O presente estudo traz uma reflexão sobre os discursos culturais afro-brasileiros e o lugar ocupado pela poesia em meio a uma sociedade racista. A pesquisa tem como propósito fazer um estudo da poesia de Oliveira Silveira (1968, 1970, 1977, 1981, 1987). Leva-se em consideração a relação da produção poética de Oliveira com as propostas do movimento da Negritude e o diálogo lúcido que o mesmo estabelece com poetas vinculados ao referido movimento e como Silveira sugere dentro da literatura a negritude como uma forma de intersecção na poesia brasileira. A proposta aqui apresentada observa também o hibridismo na poética de Oliveira Silveira ao se enfatizar um olhar sobre uma escrita comovida pelo traço do entre-lugar do discurso. Analisa-se a caracterização de uma literatura gerada pelo tom de denúncia ao desconstruir historicamente o que há muito tempo se estabelece como democracia racial . Em cumplicidade com a poesia regional do Rio Grande do Sul, a poesia de Oliveira vem permeada pela diversidade de ritmos que traduzem o legado da cultura negra mundo afora. Essa pesquisa sustenta-se nos estudos de Eduardo de Assis Duarte (2005, 2011) e Kabengelê Munanga (2008, 2009) sobre Negritude e Identidade na literatura afro-brasileira, que se caracteriza como um movimento de consciência pela reconstrução ou mesmo revisão histórica do que foi apagado no calabouço dos navios negreiros. As leituras de Eduardo de Assis Duarte fomentam novos questionamentos, põem em dúvida a existência de uma identidade essencialista. Aponta-se nessa travessia para uma pluralidade de identidades, construídas por inúmeros grupos culturais na encruzilhada dos diversos momentos históricos. Analisam-se, portanto, a partir da crítica que Stuart Hall (2011) faz ao considerar as ideias de diásporas, as fronteiras das margens no universo da pós-colonização. Por fim, há uma encruzilhada ao se pensar a partir de Kabengelê Munanga, o discurso da negritude e da identidade negra nas relações sociais e culturais afrodescendentes

Setor escuro do universo: uma análise termodinâmica

Significant observational effort has been directed to unveiling the nature of the so-called dark energy. However, given the large number of theoretical possibilities, it is possible that this a task cannot be based only on observational data. In this thesis we investigate the dark energy via a thermodynamics approach, i.e., we discuss some thermodynamic properties of this energy component assuming a general time-dependent equation-of-state (EoS) parameter w(a) = w0 + waf(a), where w0 and wa are constants and f(a) may assume different forms. We show that very restrictive bounds can be placed on the w0 - wa space when current observational data are combined with the thermodynamic constraints derived. Moreover, we include a non-zero chemical potential μ and a varying EoS parameter of the type ω(a) = ω0 + F(a), therefore more general, in this thermodynamical description. We derive generalized expressions for the entropy density and chemical potential, noting that the dark energy temperature T and μ evolve in the same way in the course of the cosmic expansion. The positiveness of entropy S is used to impose thermodynamic bounds on the EoS parameter ω(a). In particular, we find that a phantom-like behavior ω(a) < −1 is allowed only when the chemical potential is a negative quantity (μ < 0). Thermodynamically speaking, a complete treatment has been proposed, when we address the interaction between matter and energy dark

Atividades comportamentais e comportamento alimentar de rã touro, Lithobates catesbeianus (Shaw, 1802), de pigmentação normal e albina em cativeiro

The behavior of bullfrogs reared in captivity must be well understood to support management practices that use efficient feeding regimes. In general, bullfrogs reared in captivity have normal pigmentation, but to develop an enhanced product, some studies have investigated the introduction of albino individuals in frog farms. The present study characterized the behavior of both pigmented and albino bullfrogs reared in captivity. In an initial experiment, 48 bullfrogs (70.5 ± 25.6 g) housed in small stalls were fed once a day at random times. Frogs were filmed and the images showed that both the pigmented and albino varieties behaved similarly: food intake was more frequent at dawn followed by light periods; moving and resting in dry areas may be associated to feeding events; frogs appeared to anticipate feeding time and to rest in the water more frequently in periods other than feeding time; daylight is the recommended period for feeding both pigmented and albino frogs. In a second experiment, 72 albino bullfrogs were fed at fixed times (10 a.m. or 4 p.m.) in small stalls. An initial weight of 23.8 ± 7.6 g was considered to evaluate frog performance, and after the animals reached 60.0 ± 20.0 g, they were filmed for behavior analyses. Food intake varied as a function of feeding time, and frogs were more likely to eat during the early hours of the day and immediately after receiving fresh food. Frogs fed only in the afternoon changed their behavior. Food supplied twice a day stimulated the albino frogs to eat at different times, but did not increase growth. Although fresh food stimulated feeding behavior, food intake was more frequent at dawn. Food supplied at this time of day should therefore be further investigated. The results did not indicate a more suitable feeding time (10 a.m. or 4 p.m.) for albino bullfrogs, or any advantage in using two feedings per day. The results provide xvi important information about bullfrogs in terms of food supply regime and activity preferences throughout the day. This novel information will contribute to future studies in this area

Relação entre padrão comportamental, estágios do ciclo de muda e atividade de enzimas digestivas proteolíticas em juvenis do camarão marinho Litopenaeus vannamei (Crustacea: Penaeidae)

Shrimp farming in Brazil is a consolidated activity, having brought economical and social gains to several states with the largest production concentrated in the northeast. This fact is also reflected in higher feed intake, necessitating a more efficient feed management. Currently, management techniques already foresee food loss due to molting. In this sense, studies relating shrimp s digestive physiology, molting physiology and behavioral response of shrimp feed can optimize the feed management. Thus, our study aimed to evaluate the behavioral response of the marine shrimp L. vannamei (Crustacea: Penaeidae) in accordance with the stages of moulting cycle and feeding schedules based on higher or lower activity of proteolytic digestive enzymes; also, to investigate the influence of feeding schedule on hepatosomatic index and non-specific and specific protease activity (trypsin). Experiments were carried out at the Laboratory of Shrimp Behavioral Studies at UFRN in partnership with the Laboratory of Enzimology UFPE. Juveniles of L. vannamei weighting 5.25 g (+ 0.25 g) were kept in aquaria at a density of 33 shrimp m -2. In the first experiment, shrimp were fed in the light phase or in the dark phase for 8 days; in the ninth day, the animals were observed for 15 minutes every hour during the 12 hours of each phase of the photoperiod. We recorded the frequency of inactivity, exploration, food intake, burrowing, swimming and crawling behavior. At the end of the 12th observation session, the shrimp were sacrified and classified by the method of setogenesis in the molt cycle stages A, B, C, D0, D1, D2 or D3. We found that the shrimp in A stage show high levels of inactivity. Moreover, the frequency of food intake was very low. The shrimp in D3 stage also had low food intake and high inactivity associated with elevated frequencies of burrowing. In the second experiment, shrimp were kept in physiological acclimation to experimental conditions for 28 days, distributed in 12 treatments in the light phase and 12 treatments in the dark phase. In the end, the animals were sacrified and dissected to assess non-specific and specific protease activity (trypsin) activity. In general, these parameters did not vary among animals fed in the light phase and those fed in the dark phase. However, significant differences were found in the activity of specific and nonspecific proteases in relation to food treatment. In the light phase, the major proteolytic activities converged to 10 hours after the start of the light phase, while the lowest activities converged to 6 hours after the beginning of this phase. In the dark phase, the highest enzyme activity converged to 12 hours after the onset of phase, while the lowest activities converged to 3 hours after the onset of phase. In the third experiment, we sought to evaluate the behavioral responses of shrimp in relation to dietary treatments based on higher or lower activity of proteolytic enzymes, considering the results of the second experiment. The behavioral categories observed were the same as the ones in the first experiment, with observations of 30 minutes (15min before and 15min after food supply). We found variation in behavioral responses as a function of the treatments, with greater intake of food in shrimp fed during the period of greatest activity of proteolytic enzymes, in the light phase. Thus we see that periodic events associated with the shrimp s physiology interfere in their behavioral responses, revealing situations that are more adjustable to the provision of food, and consequently optimizing feeding management

Ritmo circadiano de atividade motora e distribuição diária dos comportamentos afiliativos ao longo da fase juvenil em saguis (callithrix jacchus)

The temporal allocation of the active phase in relation to light and dark cycle (LD) changes during puberty in humans, degus, rats and rhesus. In marmosets, the animal model used in several biomedical researches, there is evidence of a delay at the beginning of the active phase and an increase in total daily activity after onset of puberty. However, as this aspect was evaluated in animals maintained in natural environmental conditions, it was not possible to distinguish between the effects of puberty and of seasonality. Furthermore, as motor activity is the result of different behaviors in this species, it is also important to characterize the diurnal distribution of other behaviors in juvenile stage. With the aim of characterizing the circadian rhythm of motor activity and the diurnal profile of affiliative behavior in marmosets, the motor activity of 5 dyads juveniles between 4 and 12 months of age and their parents was recorded continuously for actímetro. The families were maintained under artificial LD 12:12 h, constant temperature and humidity. The duration of grooming behavior, proximity and social play among juveniles was recorded 2 times a week in sessions of 15 minutes each hour of the active phase. Afetr onset of puberty in juvenile, it was observed that there was no change in the parameters of circadian motor activity rhythm which were common to most animals. Despite the absence of pubertal modulation, it was observed that the circadian activity profiles have stronger synchrony between individuals of the same family than that of different families, which may indicate that the circadian activity rhythm was modulated by the dynamics of social interactions. In relation to age, the total daily activity and the ratio between evening and morning activity (EA/MA) were higher in juveniles than in adults, which may be associated with differences in the circadian timing system between age groups. Furthermore, the onset of the 10 consecutive hours of higher activity (M10) occurred earlier in adult males than in other members of the group, probably as a way to avoid competition for resources in one of the first activities of the day that is foraging. During the juvenile stage, there was an increase in total daily activity that may be associated with increased motor ability of juveniles. In addition to the circadian activity rhythm, the daytime profile of proximity and social play behaviors was similar between the 5th and 12th month of life of juveniles, in which the interval between 7- 10 h in the morning showed the highest values of proximity and lower values of play social. Moreover, the duration of the grooming showed a similar distribution to adults from the 8th month, wherein the higher values occurring at the interval between 11 14 h of day. Considering the results, the parameters of the circadian activity rhythm had a greater influence of social factors than puberty. In relation to age, there were no changes related to the allocation of the active phase in relation to the LD cycle, but total daily activity, the ratio AV/AM and the start of the M10 is possible to observe differences between juveniles and adults

Expressão de fos após pulso de escuro no núcleo pré- geniculado do tálamo do sagui (Callithrix jacchus)

The pregeniculate nucleus (PGN) of the primate s thalamus is an agglomerate neuronal having a cap shaped located dorsomedially to the main relay visual information to the cerebral cortex, the dorsal lateral geniculate nucleus (GLD). Several cytoarchitectonic, neurochemical and retinal projections studies have pointed PGN as a structure homologous to intergeniculate leaflet (IGL) of rodents. The IGL receives retinal terminals and appears to be involved in the integration of photic and non-photic information relaying them, through geniculo-hypothalamic tract (TGH), to the main circadian oscillator in mammals, the suprachiasmatic nucleus (SCN) of the hypothalamus. Thus, the IGL participates in the control of the biological rhythm by modulating the activity of the SCN. Pharmacological and IGL injury studies conclude that it is critical in the processing of non-photic information which is transmitted to the SCN. Other studies have found that especially neurons immunoreactive to neuropeptide Y (NPY) respond to this type of stimulation, determined by its colocation with the FOS protein. Has not been determined if the PGN responds, expressing the FOS protein, to the non-photic stimulus nor the neurochemical nature of these cells. Thus, we apply a dark pulse in the specifics circadian phases and analyze the pattern of expression of FOS protein in PGN of the marmoset (Callithrix jacchus). We found that in all animals analyzed the FOS expression was higher in the experimental than in the control group. There was a higher expression of FOS when the dark pulse was applied during the subjective day between the groups. Still, a subregion of the PGN, known by immunoreactive to NPY, had a greater number of FOS-positive cells in relation to his other just close dorsal region. Our data corroborate the theory that the PGN and IGL are homologous structures that were anatomically modified during the evolutionary process, but kept its main neurochemical and functional characteristics. However, injury and hodological studies are still needed for a more accurate conclusion

Estudo da preferência manual durante o desenvolvimento ontogenético em sagüi comum ( Callithix jacchus)

The study of manual preference is a widely used approach to investigate cerebral laterality in nonhuman primates. However, in New World primates, little is known about the ontogenesis of hand use asymmetry, in both forced and spontaneous activities, as well as how they correlate with sexual hormones. Accordingly, a longitudinal study was conducted on the manual preference of 6 female and 4 male common marmosets (Callithrix jacchus). The study included the record of forced tests to reach for the food using only one hand (forced activity) and activities such as grooming (auto and social), scratching, grasping the food and hanging, in weekly sessions from the infantile (4 months) to the early adult phase (15 months). Feces samples were also collected, at least once a week, to evaluate the level of gonadal steroids and their influence on these behaviors. In the forced activity, the results confirm the influence of the development period on manual preference during feeding, shown by the increase in lateral stability when grasping the food between the juvenile and adult phases. During this period, a sexual hormone effect on development was also observed, mainly of progesterone in females and androgen in males, but no difference between sexes was found. In the females, progesterone also influenced the manual preference index, with a proportional increase in the degree of manual asymmetry during puberty. With respect to spontaneous activities, the animals showed proportional use of both hands when scratching, hanging, holding the food and grooming. A positive correlation was also found between the preference for holding the food in forced activities and in spontaneous activities