Hippocampal Neuronal Overflow and Cortical Reconstruction: A Hypothesis on the Formation of Neural Networks Unique to the Human Brain
Year: 2026
Type: preprint
Abstract: This study explores the neural basis of humans’ unique cognitive abilities, focusing on the extensive neuronal migration in white matter that continues for nearly 18 months after birth. Traditional views attribute these migrating neurons to the ventral telencephalon during the fetal period, but this cannot adequately explain their scale and duration. We propose the “Hippocampal Neuronal Overflow and Cortical Reconstruction” hypothesis: hippocampal neurogenesis in human infants peaks perinatally, and under rich environmental stimulation the survival of new hippocampal neurons increases markedly. When their number exceeds the hippocampus’s capacity, they overflow into the white matter and migrate without a fixed route, occupying channels used by normally migrating neurons and displacing them. We term both groups “hippocampal-type neurons.” The depletion of normal neurons from the migration stream may also trigger compensatory proliferation at their source. Hippocampal-type neurons distribute across the frontal, insular, and parietal cortices and parts of the temporal cortex, where they may form a novel neural network. This overflow may be a developmental mechanism unique to humans, and the network may underlie human-specific language, memory transformation, and advanced cognition, offering a new perspective on the uniqueness of human brain development.
Source: OSF Preprints (OSF Preprints)
Author: Jue Wang
Language: English
Subfield: Developmental Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7223299914