Astrocytes of the Anterior Commissure Regulate the Axon Guidance Pathways of Newly Generated Neocortical Neurons in the Opossum .

In marsupials, upper-layer cortical neurons derived from the progenitors of the subventricular zone of the lateral ventricle (SVZ) mature morphologically and send their axons to form interhemispheric connections through the anterior commissure. In contrast, eutherians have evolved a new extra callosal pathway, the corpus callosum, that interconnects both hemispheres. In this study, we aimed to examine neurogenesis during the formation of cortical upper layers, including their morphological maturation in a marsupial species, namely the opossum ().

Adult Neurogenesis in the Mammalian Hypothalamus: Impact of Newly Generated Neurons on Hypothalamic Function.

In mammals, adult neurogenesis was first demonstrated in the subventricular zone of the lateral ventricle (SVZ) and the dentate gyrus of the hippocampal formation. Further research showed that adult neurogenesis persists in other brain structures, such as the cerebral cortex, piriform cortex, striatum, amygdala, and hypothalamus. However, the origin of newly generated cells in these structures is not clear.

Impaired olfactory neurogenesis affects the performance of olfactory-guided behavior in aged female opossums.

Increasing evidence has indicated that adult neurogenesis contributes to brain plasticity, although function of new neurons is still under debate. In opossums, we performed an olfactory-guided behavior task and examined the association between olfactory discrimination-guided behavior and adult neurogenesis in the olfactory bulb (OB). We found that young and aged opossums of either sex learned to find food buried in litter using olfactory cues.