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

Abstract

The aim of the study was to investigate the morphology, density and immunostaining intensity of calbindin (CB)-positive neurons of dentate gyrus (DG) in new-born (P0) and 21-day-old (P21) male Acomys cahirinus mice from dams receiving β-hydroxy-β-methylbutyrate (HMB) during pregnancy. Different substances administrated to pregnant dams may affect the calcium ion homeostasis which is crucial for the proper brain development of their offspring. DG with hilus (H) plays an important role in memory and learning processes. Calcium levels in DG are regulated by buffering proteins like calbindin D28k (CB). Experimental dams were orally treated with HMB at a dose of 0.2g/kg b.w. Half of new-born animals were euthanised after birth and the rest after the 21st day of life. The brains were dissected and embedded in paraffin blocks using a routine histological technique. In order to demonstrate CB protein expression an immunohistochemical peroxidase-antiperoxidase reaction was conducted. The results of the study did not reveal important morphological alterations. There were no statistically significant changes in the density of the studied cells either in P0 and P21 animals. However, the authors have demonstrated a statistically significant increase of the average CB-immunostaining intensity in nuclei and cytoplasm in both age groups. It may be a result of a compensation effect to alterations that occurred under the influence of HMB. On the basis of the conducted research, it may be assumed that HMB activity in DG may provide long-term consequences.