A Love affair Across Generations: A Lamarckian Reincarnation?
Eric Jensen alerted me to a research study published in the February 4th Journal of Neuroscience — Transgenerational Rescue of a Genetic Defect in Long-Term Potentiation and Memory Formation by Juvenile Enrichment. We both had the same initial WOW! feeling that we had experienced when we first read about the discovery of mirror neurons a decade+ ago.
The study’s findings seemed to suggest that acquired characteristics can be genetically transmitted, a Lamarckinan belief that had long been discarded by biologists. This seemed improbable, so we decided to check out what the scientific community thought. It’s the kind of research that educators certainly need to understand because the potential educational implications are profound, no matter how this particular study sorts out.
I’ve thus appended the following information below: (1) the abstract and reference of the original sttudy, (2) a link to a non-technical report in the current issue of New Scientist, (3) a link to a non- technical explanation of the research in Medical News Today, and (4) a link to a recent extended non-technical New Scientist article on the issue of non-genetic inheritance. Eric will post his commentary on the research in the March edition of his Brighter Brain Bulletin newsletter.
To put it simply: The researchers studied long-term potentiation (LTP), in which longer and more robust synaptic activation occurs. LTP is the basic mechanism for learning and memory formation.
Juvenile mice placed into an enriched environment (EE) developed enhanced LTP capabilities that they later transmitted to their own offspring during embryogenesis (rather than through later maternal instruction), and these effects persisted even when the offspring weren’t in an EE. The study concluded that a stimulating juvenile environment can thus influence the composition of signaling networks that influence synaptic plasticity and memory formation in the enriched mouse, and also in its future offspring.
The problem with this research appears to be over whether the transmitted effects occurred via genetic changes or through something else in the mother’s uterine environment. A female’s eggs develop early in life to be distributed later, so it’s improbable that a female’s juvenile experiences would alter the DNA in her eggs. A more probable explanation may be that any changes in the mother’s brain that occur via an EE are represented as currently ill- understood signaling molecules that pass through the placental barrier into the embryonic brain.
For educators, this research simply adds to our own strong belief that long-term benefits accrue from a stimulating early environment that encourages curiosity and exploration. The research builds on earlier EE studies by William Greenough, Marian Diamond, and others.
I don’t know how this line of rodent research could be studied in humans, given our more complex culture, much longer developmental trajectory, and the ethical constraints of such research. But then folks initially thought that it would be almost impossible to study mirror neurons in people, so who knows how scientists will creatively explore this issue.
It’s thus a time for educational leaders to educate themselves about the entire emerging issue, rather than to immediately speculate about classroom applications. We’re living in such an exciting time, with all sorts of long held-beliefs about our brain and cognition being re- examined by cognitive neuroscientists, and a similar re-thinking of educational policies and procedures occurring in the political and educational arenas. If I had to begin anew in search of an intellectually stimulating 21st century career, education would be my choice in a heartbeat.
And as long as I’m being effusive, Happy 200th Birthday Charles Darwin and Abraham Lincoln. Nice legacies, guys!
- Reference: Transgenerational Rescue of a Genetic Defect in Long-Term Potentiation and Memory Formation by Juvenile Enrichment. The Journal of Neuroscience, February 4, 2009, 29(5):1496–1502 Junko A. Arai,1 * Shaomin Li,1 * Dean M. Hartley,2 and Larry A. Feig
- ABSTRACT: The idea that qualities acquired from experience can be transmitted to future offspring has long been considered incompatible with current understanding of genetics. However, the recent documentation of non-Mendelian transgenerational inheritance makes such a “Lamarckian”-like phenomenon more plausible. Here, we demonstrate that exposure of 15-d-old mice to 2 weeks of an enriched environment (EE), that includes exposure to novel objects, elevated social interactions and voluntary exercise, enhances long-term potentiation (LTP) not only in these enriched mice but also in their future offspring through early adolescence, even if the offspring never experience EE. In both generations, LTP induction is augmented by a newly appearing cAMP/p38 MAP kinase-dependent signaling cascade. The transgenerational transmission of this effect occurs from the enriched mother to her offspring during embryogenesis. If a similar phenomenon occurs in humans, the effectiveness of one’s memory during adolescence, particularly in those with defective cell signaling mechanisms that control memory, can be influenced by environmental stimulation experienced by one’s mother during her youth.
- Can experiences be passed on to offspring? (New Scientist)
- Rewriting Darwin: The New Non-Genetic Inheritance (New Scientist)
– Dr. Robert Sylwester is an Emeritus Professor of Education at the University of Oregon, the author of multiple books such as The Adolescent Brain: Reaching for Autonomy (Corwin Press, 2007) and many journal articles, and member of SharpBrains Scientific Advisory Board. In-depth interview with him Here.