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INSTITUTE OF ZOOLOGY

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Ongoing projects

Raising ostriches in Germany – Impact of climate and season on mortality, activity pattern and body temperature (Katja Fuhrer)

The aim of this study is to investigate the animal welfare related questions of commercial ostrich-breeding in Germany. In order to gain information about this question, the impact of weather and season on physiological and morphological parameters as well as the behaviour of the animals is assessed.

Microdialysis for melatonin and neurotransmitters/neuropeptides in the pineal gland and brain of Djungarian hamsters (Annika Herwig)

It is the aim of this project to further characterize the circadian system of Phodopus by measuring “on-line” by way of microdialysis another direct clock output function, namely rhythmic melatonin production in the pineal gland. How can the in vivo circadian system be affected by external influences like e.g. light-pulses or pharmaka? Does there exist a feedback form th pineal gland to the circadian clock?

Rhythmicity and degeneration of the circadian system in Phodopus sungorus (Frauke Perl)

Circadian rhythms provide organisms with a inner and outer temporal order.The stability of these rhythms underly processes of aging. These aging-processes are to be investigateted by chronobiological (light-pulses, actogramms/periodogramms young vs. old) and immunohistochemical methods (different neuropeptides in the suprachiasmatic nucleus, the masterclock of the circadian system) at different times of the circadian cycle.

Influence of Per1 and Per2 on the reproductive success in female mice (Violetta Pilorz)

Successful reproduction involves precisely timed events. Therefore, we would expect that from pregnancy to parturition and the raising of young, numerous physiological and behavioural events occur within a temporal program. The circadian system is a mechanism that modulates interactions for such processes. To characterise the circadian reproductive rhythm I want to focus on the effects of two molecular components of the main clock, Per1 and Per2, on physiological and behavioural processes during the reproductive phase. In addition, physiological components such as metabolic rate, body temperature and corticosteroid metabolites that are regulated by the circadian clock, will be determined.

Impact of locomotory activity on the circadian rhythmicity of Phodopus sungorus after two 15-min light pulses in subsequents nights (Frank Scherbarth)

Hamsters whithout a running wheel loose their circadian activity pattern - at least a certain percentage - after a double light pulse in subsequent nights, even if they are held in a normal light-dark cycle. Hamster that have access to a running wheel do not show arhythmic behaviour. Therefore, the influence of activity is investigated by transfering the animals in constant darkness after the second light pulse.

Do sunset and sunrise refer to lights on and off in Phodopus sungorus? Running wheel activity as indicator for the subjective night under natural light conditions (Frank Scherbarth)

The running wheel activity of Djungarian dwarfhamster is restricted to the scototphase under artificial light conditions (e.g. L:D 16:8). Hence, running wheel activity should reflect the subjective night of the animals under natural light conditions.

Astrocytes in the suprachiasmatic nucleus (Nadja Borsum )

Allthough, there are a thousands of neurons in the SCN (e.g. 10'000 to 16'000 in rats) and each of these with its own circadian rhythm, the signal emerging outside is highly synchronised between the neurons. The importance of astrocytes for the synchronisation of the neuronsin the SCN of mammals, however, is virtually unknown. In this study, the contribution of the astrocytes to the synchronisation process is assessed in cell cultures of SCN cells. The signalling processes in these cell cultures were observed via calcium imapging.

Finished projects

Studies of the function of synaptoid microvesicals in the pineal of rats (Rattus norvegicus) and gerbils (Meriones unguiculatus)(Heike Pabst)

[Abstract]

Physiological Aspects of the circadian rhythmicity of small mammals (Haiko Dernbach)

The metabolic rate of Djungarian dwarf-hamster (Phodopus sungorus) and mouse (Mus musculus) were measured under various lighting conditions. [Abstract]

Characterisation of the light induced arrhythmia of the circadian system of Djungarian dwarf-hamsters (Phodopus sungorus) on physiological and molecular level (Henning Voigt)

[Abstract]

Characterisation of Per mutant mice (Robert Dallmann)

[Abstract]

Contact
2009-03-27