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.

THE STUDY:

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.

THE SIGNIFICANCE:

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!

Resources:

- 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)

- What Your Moth­er Did When She Was A Child May Have An Effect On Your Mem­o­ry and Learn­ing Abil­i­ty (Med­ical News)

- Rewrit­ing Dar­win: The New Non-Genet­ic Inher­i­tance (New Scientist)

Robert Sylwester Learning and the BrainDr. 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.

About SharpBrains

SHARPBRAINS is an independent think-tank and consulting firm providing services at the frontier of applied neuroscience, health, leadership and innovation.
SHARPBRAINS es un think-tank y consultoría independiente proporcionando servicios para la neurociencia aplicada, salud, liderazgo e innovación.

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