Neurogenesis is one of modern neuroscience’s key theories – considered to be involved in memory formation and emotion regulation as well as implicated in a number of brain disorders, including depression, schizophrenia and Alzheimer’s disease.
Yet these theories are based almost exclusively on data from animal studies, mainly birds and rodents. What then is the relevance of neurogenesis to human brain function and dysfunction?
Human post mortem studies in this area are relatively few, and necessarily limited by their nature. In general, there appears to be a low level of neurogenesis in adult humans as measured by markers of proliferating cells in the subgranular and subventricular zones, and when evidence is found for an abnormality of neurogenesis in a disease state, it is impossible to determine if this was cause, effect or incidental.
It was therefore with considerable acclaim that a paper in Science by Professors Mirjana Maletic and Petar Djuric was received in 2007, suggesting that a tiny, almost invisible signal of the human proton spectroscopic spectrum at 1.28ppm was in fact unique to neural progenitor cells and hence a new method for quantifying neurogenesis in the live brain.
Since then, the work has been subject to intense scientific controversy, partly on mathematical signal processing grounds, and partly on empirical grounds.
In 2010, AProf Valenzuela won a NHMRC grant in collaboration with Professors Maletic and Djuric, as well as many other researchers from around Australia and internationally, to run a series of decisive studies on the 1.28ppm signal.
The aims of this project are to:
- Establish that the 1.28ppm can be reliably detected in known neurogenic regions (hippocampus and around the ventricles) and is absent in non-neurogenic regions.
- Show that the 1.28ppm signal declines predictably in the human hippocampus in late life.
- Show that Electroconvulsive Treatment (ECT) in adults with severe depression leads to an increase in hippocampal 1.28ppm signal – as predicted from many animal studies.
The team is well on the way to meeting our aims and plans to submit a publication about this work in 2012.
Neuroimaging as Endpoints in Clinical Trials Summer Workshop, Provence France, June 2010
CHDI Workshop on Exercise-Drug Synergy: Neuroprotection and Neural Plasticity in Huntington’s Disease, New York , February 2011
NHMRC Project Grant ID#1004152, Pfizer Neuroscience Grant.
- Prof Mirjana Maletic-Savatic – Baylor Medical College, Texas
- Petar Djuric – Stony Brook University, New York