LAUSR

The dentate gyrus (DG) with hilus (H) plays an important role in the processes of memory and learning and it is responsible for spatial navigation. A neurogenesis takes place in this area in adult individuals (1, 9, 10). In the DG of different species of animals the layers: stratum moleculare (SM), stratum granulosum (SG) and hilus (H) were distinguished (8, 18). A proper functioning of the area depends largely on the concentration of calcium ions in neurons. They participate in the development of the nervous system by affecting cell divisions, synaptogenesis and neuronal net formation. In neurons they are responsible for synthesis, axonal transport and a release of neurotransmitters (3, 4, 23). Neuronal calcium levels are strictly regulated by calcium-binding proteins. These include the calbindin-D28k (CB), a buffering and sensory protein (13, 21). CB in the DG of adult animals is present mainly in granular cells localised near SM. These cells are the excitatory glutamatergic neurons constituting 90% of all neurons of this area. Moreover, CB is localised in a small number of interneurons in SM and SG, in basket cells under or in SG and in H (21, 24, 25). The protein stimulates granular cells-mossy fibres system increasing a release of neurotransmitters in the nerve endings Influence of oral administration of HMB to pregnant dams on calbindin expression in the dentate gyrus of the hippocampus during postnatal development in spiny mice offspring