Follicular development in European ground squirrels (Spermophilus citellus) in different phases of the annual cycle
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منابع مشابه
Hibernation effects on memory in European ground squirrels (Spermophilus citellus).
Effects of hibernation on memory were tested in European ground squirrels (Spermophilus citellus). The animals were trained in summer to successfully accomplish two tasks: a spatial memory task in a maze and an operant task on a feeding machine. One group hibernated normally, and the other was prevented from hibernation by maintaining ambient temperature at 22 degrees C. In spring, the same tas...
متن کاملDaily Activity Pattern in Free-living European Ground Squirrels Spermophilus citellus (Mammalia: Rodentia) from Northwestern Bulgaria
The study describes the daily activity of the European ground squirrel in an experimental plot, situated in a heavily grazed pasture near the town of Knezha, Northwestern Bulgaria. Above ground activity was recorded with a visual scanning procedure in summer and autumn of 2006. In summer animals emerged on an average 1.94 h after the civil twilight at dawn and the active period lasted about 11 ...
متن کاملDynamics in the ultrastructure of asymmetric axospinous synapses in the frontal cortex of hibernating European ground squirrels (Spermophilus citellus).
Recent theories on the function of arousals from torpor in hibernating mammals focus on the repair of the central nervous system from damage accumulating during prolonged hypothermia. In this framework, we investigated the synaptic ultrastructure in Layer 2 of the frontal cortex from hibernating European ground squirrels (Spermophilus citellus) sacrificed at four different phases in the torpor-...
متن کاملNatural entrainment without dawn and dusk: the case of the European ground squirrel (Spermophilus citellus).
Observational data collected in the field and in enclosures show that diurnal, burrow-dwelling European ground squirrels (Spermophilus citellus) never were above ground during twilight at dawn or at dusk. The animals emerged on average 4.02 h (SD = 0.45) after civil twilight at dawn and retreated in their burrows on average 2.87 h (SD = 0.47) before civil twilight at dusk. Daily patterns of lig...
متن کاملNonphotic entrainment in a diurnal mammal, the European ground squirrel (Spermophilus citellus).
Entrainment by nonphotic, activity-inducing stimuli has been investigated in detail in nocturnal rodents, but little is known about nonphotic entrainment in diurnal animals. Comparative studies would offer the opportunity to distinguish between two possibilities. (1) If nonphotic phase shifts depend on the phase of the activity cycle, the phase response curve (PRC) should be about 180 degrees o...
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ژورنال
عنوان ژورنال: REPRODUCTION
سال: 2008
ISSN: 1470-1626,1741-7899
DOI: 10.1530/rep-08-0090