Daily rhythm of rumination in the goat (Capra hircus) is not driven by feeding.

Rumination shows a nocturnal rhythmic pattern in day-active ruminants. Although feeding has been shown to quantitatively modulate rumination, it is not clear yet if feeding rhythm plays a causal role in rumination rhythm. The present study was carried out to determine whether the daily rhythm of rumination in goats under natural environmental conditions is food-dependent or not, and whether it is modulated by the season.

Sleep in the dromedary camel: features of the 'first night effect'.

The 'first night effect' (FNE) is a well-known phenomenon in polysomnographic (PSG) sleep studies, resulting in significant variations in the macrostructure of wakefulness and sleep states, particularly between the initial and subsequent sleep recording sessions. The FNE phenomenon during sleep has been studied in various species, revealing complex variations between several sessions of sleep recording. The present study used a non-invasive PSG method to examine differences between various vigilance states in four adult female dromedary camels during 4 consecutive nights and days of sleep recording.

Sleep pattern in the dromedary camel: a behavioral and polysomnography study.

Study Objectives: To investigate sleep patterns in the camel by combining behavioral and polysomnography (PSG) methods.

Methods: A noninvasive PSG study was conducted over four nights on four animals. Additionally, video recordings were used to monitor the sleep behaviors associated with different vigilance states.

Entrainment of circadian rhythms of locomotor activity by ambient temperature cycles in the dromedary camel.

In the dromedary camel, a well-adapted desert mammal, daily ambient temperature (T)-cycles have been shown to synchronize the central circadian clock. Such entrainment has been demonstrated by examining two circadian outputs, body temperature and melatonin rhythms. Locomotor activity (LA), another circadian output not yet investigated in the camel, may provide further information on such specific entrainment.

Melatonin rhythm and other outputs of the master circadian clock in the desert goat (Capra hircus) are entrained by daily cycles of ambient temperature.

In desert areas, mammals such as camel and goat are exposed to harsh environmental conditions. The ambient temperature (Ta) cycles have been shown to entrain the circadian clock in the camel. In the present work, we assumed that, in the goat living in a desert biotope, Ta cycles would have the same synchronizing effect on the central clock.

Dataset concerning haematological and biochemical parameters changes in show jumping horses subjected to exercise and plasmapheresis session.

This article presents data on the effect of plasmapheresis on clinical, haematological and biochemical parameters in horses following exercise and after a plasmapheresis session. This blood filtration technique was realised on six jumping horses (plasmapheresis group) that underwent three consecutive days of graded physical exercise. The control group (n = 6) went through the same exercise but was not subjected to the plasmapheresis session.

Plasmapheresis Effect on Hematological and Biochemical Parameters in Athletic Horses Subjected to Exercise.

To evaluate the effect of plasmapheresis on clinical, hematological, and biochemical parameters after exercise, a plasmapheresis session was realized on six jumping horses (plasmapheresis group) that underwent three consecutive days of physical graded exercise. The control group (n = 6) went through the same exercise but not subjected to the plasmapheresis session. Seventeen milliliters of plasma/kg of body weight was harvested from each horse.

The dromedary camel displays annual variation in hypothalamic kisspeptin and Arg-Phe-amide-related peptide-3 according to sex, season, and breeding activity.

The dromedary camel (Camelus dromedarius) is a desert mammal whose cycles in reproductive activity ensure that the offspring's birth and weaning coincide with periods of abundant food resources and favorable climate conditions. In this study, we assessed whether kisspeptin (Kp) and arginine-phenylalanine (RF)-amide related peptide-3 (RFRP-3), two hypothalamic peptides known to regulate the mammalian hypothalamo-pituitary gonadal axis, may be involved in the seasonal control of camel's reproduction. Using specific antibodies and riboprobes, we found that Kp neurons are present in the preoptic area (POA), suprachiasmatic (SCN), and arcuate (ARC) nuclei, and that RFRP-3 neurons are present in the paraventricular (PVN), dorsomedial (DMH), and ventromedial (VMH) hypothalamic nuclei.

Validation of locomotion scoring as a new and inexpensive technique to record circadian locomotor activity in large mammals.

Background: The locomotor activity (LA) rhythm, widely studied in rodents, has not been fully investigated in large mammals. This is due to the high cost and the brittleness of the required devices. Alternatively, the locomotion scoring method (SM), consisting of attribution of a score to various levels of activity would be a consistent method to assess the circadian LA rhythm in such species.

Effect of Melatonin Implants during the Non-Breeding Season on the Onset of Ovarian Activity and the Plasma Prolactin in Dromedary Camel.

To examine a possible control of reproductive seasonality by melatonin, continual-release subcutaneous melatonin implants were inserted 4.5 months before the natural breeding season (October-April) into female camels (Melatonin-treated group). The animals were exposed to an artificial long photoperiod (16L:8D) for 41 days prior to implant placement to facilitate receptivity to the short-day signal that is expected with melatonin implants.

The Suprachiasmatic Nucleus of the Dromedary Camel (): Cytoarchitecture and Neurochemical Anatomy.

In mammals, biological rhythms are driven by a master circadian clock located in the suprachiasmatic nucleus (SCN) of the hypothalamus. Recently, we have demonstrated that in the camel, the daily cycle of environmental temperature is able to entrain the master clock. This raises several questions about the structure and function of the SCN in this species.

Main anatomical and histological features of the tonsils in the camel (Camelus dromedarius).

The tonsils, located around the pharyngeal cavity, constitute the first defence barrier against intruding microorganisms and antigens. The present work aimed to study the anatomical and histological aspects of camel tonsils in order to elucidate their role. The study was carried out on 12 camel heads fixed by infusion with 10 % neutral buffered formalin.

Daily regulation of body temperature rhythm in the camel (Camelus dromedarius) exposed to experimental desert conditions.

In the present work, we have studied daily rhythmicity of body temperature (Tb) in Arabian camels challenged with daily heat, combined or not with dehydration. We confirm that Arabian camels use heterothermy to reduce heat gain coupled with evaporative heat loss during the day. Here, we also demonstrate that this mechanism is more complex than previously reported, because it is characterized by a daily alternation (probably of circadian origin) of two periods of poikilothermy and homeothermy.

Entrainment of the circadian clock by daily ambient temperature cycles in the camel (Camelus dromedarius).

In mammals the light-dark (LD) cycle is known to be the major cue to synchronize the circadian clock. In arid and desert areas, the camel (Camelus dromedarius) is exposed to extreme environmental conditions. Since wide oscillations of ambient temperature (Ta) are a major factor in this environment, we wondered whether cyclic Ta fluctuations might contribute to synchronization of circadian rhythms.

Seasonal variations in the nycthemeral rhythm of plasma melatonin in the camel (Camelus dromedarius).

Seasonal changes in the pattern of plasma melatonin were investigated in two groups of camels (Camelus dromedarius): 11 adult and six young camels. Animals were subjected to the outdoor conditions of a desert environment. Blood samples were taken at regular intervals of about 3 hr (added to particular samples at 1 hr before then 30 min and 1 hr after sunset, and 1 hr before and 1 hr after sunrise) for 24 hr at both solstices and equinoxes of the year.

Changes in neuronal metabolism in hypothalamic periventricular regions following acute alteration of cerebrospinal fluid composition in conscious rats.

Quantitative 2-deoxyglucose (2-DG) autoradiography was employed to determine the effect of elevating cerebrospinal fluid osmolality on neuronal metabolism of hypothalamic periventricular regions in conscious rats. Injection of hypertonic mannitol solution into the dorsal third ventricle had no significant effect on local cerebral glucose utilization, whereas administration into the ventral third ventricle resulted in a significant elevation in 2-DG uptake in only the posterior pituitary, median preoptic nucleus (MnPo), median eminence and suprachiasmatic nucleus. These results indicate the contribution of a synaptic connection in the MnPo in the activation of the osmoreceptor complex.