degus<\/a>.<\/p>\nFirst, a group of infant and adult mice were trained to fear a certain environment through the use of mild electric foot shocks.<\/p>\n
Some of the adult mice were then provided access to running wheels, an activity that has been shown to boost neurogenesis. When returned to the initial environment, the adult mice who used the running wheels had largely forgotten their fear of the electric shocks, while those without the wheels maintained an association between the space and fear.<\/p>\n
From the group of infant mice a number were given drugs to slow the rate of neurogenesis to see if decreasing the generation of new neurons mitigated the forgetting normally observed in infant mice. In accordance with the researchers\u2019 hypothesis, the ability of these animals to retain memories improved in comparison to their untreated counterparts.<\/p>\n
The study was then moved to rodents whose infancy period distinctly differs from mice \u2013 and humans \u2013 guinea pigs and degus. These rodents have a shorter postnatal hippocampal neurogenesis because they are more neurologically mature at birth. That means they have extended memory retention as infants so those animals were given drugs to artificially increase neurogenesis \u2013 which resulted in forgetting.<\/p>\n
Psychologist Dr Amy Reichelt, from the University of New South Wales, said it was good the study used infant guinea pigs and degus.<\/p>\n
\u201cThese animals are born in a \u2018precocious\u2019 way \u2013 they are basically miniature adults \u2013 able to run about independently, as opposed to mice, rats and humans who are vulnerable and dependent at birth,\u201d she said.<\/p>\n
\u201cIn young animals where neurogenesis is at a high level, memory circuits are constantly changing, so this supports that certain memories are \u2018pruned\u2019 out and thus forgotten \u2013 supporting the notion of infantile amnesia.\u201d<\/p>\n
How could you forget?<\/h2>\n
Previous studies have examined the relationship between hippocampal neurogenesis and memory, with a focus on its importance in the consolidation of memories in adult animals. But they have not considered how neurogenesis can also jeopardise memory retention.<\/p>\n
Behavioural psychologist Dr Jee Hyun Kim, Head of the Developmental Psychobiology Lab at Melbourne\u2019s Florey Institute of Neuroscience and Mental Health, said: \u201cIt has long been speculated that the \u2018immaturity\u2019 of the hippocampus may be responsible for infantile amnesia. Back in the days \u2018immaturity\u2019 was interpreted as dysfunctional, or low in function.<\/p>\n
\u201cHowever, recent studies speculated that immaturity can also occur in the form of hyper functionality. This study shows that the extreme plastic nature of our brains early in life can be the reason why we forget quickly episodic memories happening early in life.\u201d<\/p>\n
Infantile amnesia is not restricted to hippocampus-dependent memories in humans and animals. Dr Kim said it was likely that neurogenesis formed only a part of the story.<\/p>\n
\u201cI wouldn\u2019t be surprised if we find undiscovered neurogenesis in other parts of the brain,\u201d she said.<\/p>\n
A spotless mind<\/h2>\n
But does this research hint at ways of improving memory retention in the future?<\/p>\n
\u201cIt would not be feasible to discourage neurogenesis and reduce forgetting of existing memories,\u201d Dr Kim said, \u201cas adult neurogenesis has a well-established link to depression (low neurogenesis means high depression)\u201d.<\/p>\n
Surprisingly, it\u2019s the other side of the coin that promises more potential opportunities. Harnessing neurogenesis to destabilise pre-existent memories could have its own benefits. Dr Kim said depressed or anxious people may want to forget and focus on creating better memories and\/or thought patterns.<\/p>\n
This can be especially constructive for children who experience trauma in early life, Dr Reichelt said.<\/p>\n
\u201cIncreasing neurogenesis could be a useful therapy to treat or prevent the onset of post-traumatic stress disorder,\u201d she said.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"
http:\/\/theconversation.com\/neuron-study-helps-explain-why-we-forget-26367 9 May 2014, 6.38am AEST Neuron study helps explain why we\u00a0forget AUTHOR Madeleine Martiniello Editor at The Conversation INTERVIEWED Jee Hyun Kim\u00a0 Jee Hyun Kim is a Friend of The Conversation. Head of Developmental Psychobiology Lab at The Florey Institute of Neuroscience and Mental Health Amy Reichelt Research Fellow at UNSW Australia The … Continue reading How we forget – dentate gyrus neurogenesis is the key!<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[14,19],"tags":[],"class_list":["post-1948","post","type-post","status-publish","format-standard","hentry","category-complex-adaptive-systems","category-cool"],"_links":{"self":[{"href":"https:\/\/blog.panicola.com\/index.php?rest_route=\/wp\/v2\/posts\/1948","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.panicola.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.panicola.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.panicola.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.panicola.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1948"}],"version-history":[{"count":1,"href":"https:\/\/blog.panicola.com\/index.php?rest_route=\/wp\/v2\/posts\/1948\/revisions"}],"predecessor-version":[{"id":1949,"href":"https:\/\/blog.panicola.com\/index.php?rest_route=\/wp\/v2\/posts\/1948\/revisions\/1949"}],"wp:attachment":[{"href":"https:\/\/blog.panicola.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1948"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.panicola.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1948"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.panicola.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1948"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}