Disparity of seasonal volume changes of forebrain structures in the common shrew (Sorex araneus) suggest engagement of different mechanisms

• Autorzy: Michalski A. , Bartkowska K. , Taylor J. , Turlejski K.
• Języki publikacji: EN

Abstrakty

EN

Mechanisms of seasonal changes of brain size in Sorex shrews (Dehnel’s effect) remain largely unknown. Hypothesis postulating changes of brain cell numbers has been recently rejected (Bartkowska et al. 2008). Other possible mechanisms are reorganisation of the neuropil and change in the composition of brain tissue (e.g. dehydration). Shrews were captured in the spring, summer and autumn. Some shrews collected in the autumn wintered in captivity. Volumes of selected forebrain structures were measured stereologically on Nissl stained series of sections. Largest oscillations were found in the volume of cortex and basal ganglia. Lack of correlation between the rate of neurogenesis and the volume of hippocampus confi rms previous fi ndings. Relative quantity of myelin was determined by densitometry of sections stained with the method of Gallyas. Volumes of neocortex and hippocampus that are myelinised to a similar degree change differently, while volumes of striatum and neocortex, differing in myelin density, reduce their volumes similarly in the winter. Moreover, the overall ratio of forebrain volume to myelin quantity did not change throughout life. This implies that general dehydration may be excluded as a signifi - cant reason of brain size alterations and that different mechanisms are engaged in various brain structures. The comparison of analysed structures in terms of connectivity and water permeability by measuring levels of synaptophysin and aquaporin 4 was attempted.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2009
• Tom: 69
• Numer: 3
• Opis fizyczny: p.308

Twórcy

autor

Michalski A.

• Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology Polish Academy of Sciences, Warsaw, Poland

autor

Bartkowska K.

• Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology Polish Academy of Sciences, Warsaw, Poland

autor

Taylor J.

• Department of Animal Ecology, Institute of Biology, University of Bialystok, Bialystok, Poland

autor

Turlejski K.

• Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology Polish Academy of Sciences, Warsaw, Poland