Study of neurodegenerative changes in the CA1 area of the dorsal hippocampus in adult rats after prenatal hyperhomocysteinemia

Abstract

The work is devoted to the study of neurodegenerative changes in the ultrastructural organization in CA1 of the hippocampus in adult rats subjected to prenatal hyperhomocysteinemia (pHHC). Electron microscopy revealed signs of pathological changes in the CA1 neural networks of the dorsal hippocampus in adult pHHC rats, unlike in control ones: cell degeneration, destruction of the myelin sheath of axons, and destruction of axial cylinders of basal and apical dendrites directed from the pyramidal neurons to the Schaffer collaterals and the temporo-ammonic tractus. In control animals, a dense network of varicose extensions in the distal branches of the dendrites in the stratum oriens and stratum radiatum layers was detected using the Golgi method, providing an increased area for synaptic contacts. In pHHC rats, significant destructive changes are found in these dendritic varicosities: destruction of mitochondrial cristae and appearance of huge cisterns. In adult rats, pHHC completely negated the preference for the smell of valerian, which is a physiologically significant stimulus in the norm, indicating the negative effect of pHHC on the work of the olfactory analyzer, whose activity is closely connected with the hippocampus. These findings indicate the deleterious effect of homocysteine on the formation of the dorsal hippocampus as a morphological substrate for the integration of the incoming impulses.