GreenTracker| Scientists at Georgia Tech have overturned a major theory about the process of brain development called “late equals large.” Simply stated, the theory states that brains initially develop on similar tracks, as blank slates.
In early development, the anterior, or front, part of the brain is specified from the posterior, or back, part. After that, neurogenesis occurs as precursor cells mature to become neurons. These precursors can replicate endlessly, but once they become functional neurons, replication ends. The later the switch from precursors to mature neurons, the larger the brain, or brain region, becomes.
The “late equals large” model holds that the brains of different species, for example humans vs. mice, are similar early in initial development and differ because of the later process of neurogenesis. The more differentiated the species — mice vs humans — the more difficult it is to extrapolate data in brain development and apply it to the other.
Georgia Tech researchers confirmed that they were able to change the brain of one type of cichlid fish to resemble another, long prior to the onstart of neurogenesis. Rarely do researchers have the opportunity to conduct research on closely aligned species. The new research suggests that brain differentiation begins much earlier than previously believed. via Science Daily