The effects of age on the circadian clock system have been extensively studied, mainly in two rodent species, laboratory rat and golden hamster. However, less information is available how aging alters rhythmicity a commonly studied animal model, mouse. Therefore, present study we compared rhythm wheel-running activity adult (6–9 mo) old (19–22 C57BL/6J mice maintained under different lighting conditions for period 4 mo. During this period, were subjected to phase advances delays light-dark...

South American subterranean rodents (Ctenomys aff. knighti), commonly known as tuco-tucos, display nocturnal, wheel-running behavior under light-dark (LD) conditions, and free-running periods >24 h in constant darkness (DD). However, several reports the field suggested that a substantial amount of activity occurs during daylight hours, leading us to question whether circadian entrainment laboratory accurately reflects natural conditions. We compared patterns locomotor DD animals previously...

The authors examined spatial working memory in the Morris water maze during activity and rest periods of Wistar rats. Wheel-running was measured continuously as a marker circadian phase. To minimize possible masking effects on performance, animals were placed constant dim light day before testing tested similar conditions. Three experiments run, each them using varying their previous experience maze. Half experiment 2 to 3 h after onset (active group), other half 14 15 (inactive group). In...

The most commonly measured mouse behavior in fear conditioning tests is freezing. A technical limitation, particularly for genetic studies, the method of direct observation used quantifying this response, with potential bias or inconsistencies. We report use a computerized based on latency between photobeam interruption measures as reliable scoring criterion mice. different computer obtained during contextual showed high correlations hand-scored freezing; r values ranged from 0.87 to 0.94....

The tuco-tuco Ctenomys aff. knighti is a subterranean rodent which inhabits semi-arid area in Northwestern Argentina. Although they live underground burrows where environmental cycles are attenuated, display robust, 24 h locomotor activity rhythms that synchronized by light/dark cycles, both laboratory and field conditions. environment also poses energetic challenges (e.g. high-energy demands of digging, hypoxia, high humidity, low food availability) have motivated thermoregulation studies...

Abstract Synchronization of biological rhythms to the 24-hour day/night has long been studied with model organisms, under artificial light/dark cycles in laboratory. The commonly used rectangular cycles, comprising hours continuous light and darkness, may not be representative natural exposure for most species, including humans. Subterranean rodents live dark underground tunnels offer a unique opportunity investigate extreme mechanisms photic entrainment wild. Here, we show automated field...

Several rodent species that are diurnal in the field become nocturnal lab. It has been suggested use of running-wheels lab might contribute to this timing switch. This proposition is based on studies indicate feed-back vigorous wheel-running period and phase circadian clocks time daily activity rhythms. Tuco-tucos (Ctenomys aff. knighti) subterranean rodents but robustly laboratory, with or without access running wheels. We assessed their energy metabolism by continuously simultaneously...

Abstract While most studies of the impacts climate change have investigated shifts in spatial distribution organisms, temporal time activity is another important adjustment made by animals a changing world. Due to importance light and temperature cycles shaping patterns, patterns organisms that inhabit extreme environments with respect 24-hour cyclicity Earth potential provide insights into interrelationships among abiotic variables, behaviour physiology. Our previous laboratory Argentinean...

Activity rhythms of laboratory rodents are usually measured by running wheels, and although wheel activity-or-rest data enable straightforward rhythmic analyses, it provides limited behavioral information. In subterranean (tuco-tucos), we used bio-loggers (accelerometers) to measure activity in both lab field conditions, detecting diverse movements that compose activity. However, understanding these different accelerometer-detected components requires more complex analytical tools. Here...

Circadian rhythms are regarded as essentially ubiquitous features of animal behavior and thought to confer important adaptive advantages. However, although circadian systems rodents have been among the most extensively studied, comparative biology is restricted a few related species. In this study, organization locomotor activity was studied in subterranean, solitary north Argentinean rodent, Ctenomys knightii. The genus, Ctenomys, commonly known Tuco‐tucos, comprises more than 50 species...

The underground environment poses particular communication challenges for subterranean rodents. Some loud and low-pitched acoustic signals that can travel long distances are appropriate long-range have been suggested to be territorial signals. Long-range vocalizations (LRVs) important in long-distance Ctenomys tuco-tucos. We characterized the LRV of Anillaco Tuco-Tuco ( sp.) using recordings from free-living individuals described behavioral context which this vocalization was produced during...

Subterranean rodents spend most of the day inside underground tunnels, where there is little daily change in environmental variables. Our observations tuco-tucos (Ctenomys aff. knighti) a field enclosure indicated that these animals perceive aboveground light-dark cycle by several bouts light-exposure at irregular times during light hours day. To assess whether such pattern acts as an entraining agent circadian clock, we first constructed laboratory Phase Response Curve for 1 h light-pulses...

Living organisms anticipate the seasons by tracking proportion of light and darkness hours within a day-photoperiod. The limits photoperiod measurement can be investigated in subterranean rodents tuco-tucos (Ctenomys aff. knighti), which inhabit dark underground tunnels. Their exposure to is sporadic and, remarkably, results from their own behavior surface emergence. Thus, we endogenous exogenous regulation this its consequences measurement. In field, animals carrying biologgers displayed...

The tuco-tuco (Ctenomys aff. knighti) is among the rodent species known to be nocturnal under standard laboratory conditions and diurnal natural conditions. circadian thermoenergetics (CTE) hypothesis postulates that switches in activity timing are a response energetic challenges; daytime reduces thermoregulatory costs by consolidating warmest part of day. Studying wild animals both captive can increase understanding how temporal patterns shaped environment could serve as test CTE...

Abstract Despite striking diversity in mammalian social behavior, studies of organization have often dichotomized species by identifying them as either solitary or (i.e., group living). This tendency has been particularly pronounced for subterranean rodents, the majority which long assumed to be solitary. As a result, variation likely underestimated these animals, patterns space use suggest limited temporally dynamic opportunities interactions among conspecifics. Here, we characterize...

Triatoma infestans (Hemiptera: Reduviidae) is the main vector of Trypanosoma cruzi, etiological agent Chagas disease, in South America. Active dispersal this principal cause recolonization human dwellings previously treated with insecticides. Due to persistence populations and their movement between habitats, dispersive behavior studies are important for understanding epidemiology disease. The aim study was analyze relationship among T. females' activity levels according physiological...

Several wild rodents, such as the subterranean tuco-tucos (Ctenomys famosus), switch their time of activity from diurnal to nocturnal when they are transferred field laboratory. Nevertheless, in most studies, different methods measure each these conditions were used, which raised question whether detected change timing could be an artifact. Because locomotor and body temperature (Tb) rhythms rodents tightly synchronized because abdominal Tb loggers can provide continuous measurements across...