Distribution of GAD67-expressing neurons and morphological changes in hippocampal structures during pubertal period after acute perinatal hypoxia in rats

We investigated structural changes in the Wistar rat hippocampal CA1 field and fascia dentate during the pubertal period (on P60) after perinatal hypoxic exposure as well as the distribution of GAD67-expressing neurons in these structures. It was established that in the granular layer of the fascia dentata and in the CA1 field acute perinatal hypoxia leads to irreversible homotypic abnormalities as expressed in the reduced number of neurons and their rows as well as injury of a considerable portion of cells, which exhibit the signs of chromatolysis and vacuolization of the cytoplasm. Both in experimental and control animals, GAD67-expressing neurons in the fascia dentata are scattered diffusely and share approximately the same size of their populations. In the CA1 field, immunoreactive neurons lie in the lower rows of the pyramidal layer, while neurons in the upper layers exhibit no immunolabeling and have less synaptic structures in experimental animals than in control. We suggest that neurons in the hippocampal structures are involved in the regulation of functions and formation of prenatal pathology.