Early-Life Stress Caused by Maternal Deprivation Impacts Dendritic Morphology of Adult Male Mouse Neocortical Interneurons

A substantial body of research suggests that early-life stress (ELS) is associated with neuropathology in adulthood. Maternal deprivation (MD) is a commonly utilised model in mice for the study of specific neurological diseases. The appropriate growth of dendrites is essential for the optimal functioning of the nervous system. However, the impact of ELS on interneuron dendritic morphology remains unclear. To ascertain whether ELS induces alterations in the morphology of GABAergic inhibitory interneurons in layers II/III of the medial entorhinal cortex (mEC), the somatosensory cortex (SSC), the motor cortex (MC), and the CA1 region of the hippocampus (Hp), 9-day-old male GAD-67-EGFP transgenic mice were subjected to a 24 h MD. At postnatal day 60 (P60), the animals were sacrificed, and their brains were subjected to morphological analyses. The results indicated that MD affected the dendritic morphology of GABAergic interneurons. The mean dendritic length and mean dendritic segments of the examined cortical areas, except for the MC, were significantly decreased, whereas the number of primary dendrites was unaffected. Furthermore, the density of GAD67-EGFP-positive interneurons was decreased in the mEC and Hp, but not in the somatosensory and MC. The induction of ELS through MD in a developmental time window when significant morphological changes occur rendered the developing cells particularly susceptible to stress, resulting in a significant reduction in the number of surviving interneurons at the adult stage.