{"id":3350,"date":"2014-03-16T19:19:13","date_gmt":"2014-03-16T23:19:13","guid":{"rendered":"http:\/\/geraldguild.com\/blog\/?p=3350"},"modified":"2024-01-17T06:33:23","modified_gmt":"2024-01-17T11:33:23","slug":"can-memories-be-inherited","status":"publish","type":"post","link":"https:\/\/geraldguild.com\/blog\/2014\/03\/16\/can-memories-be-inherited\/","title":{"rendered":"Can Memories be Inherited?"},"content":{"rendered":"

There is an Indigo Girls<\/a> song called Galileo<\/a> that references a fear of motion (00:01:19 into the song) and suggests that the source of this particular fear is from “some other fool across the ocean years ago [having] crashed his little airplane<\/em>.”\u00a0 In the song, the means of transmission of this fear is reincarnation, which according to dictionary.com <\/a>is “the belief that the soul, upon death of the body, comes back to earth in another body or form<\/em>.”\u00a0 Such claims lie outside the measurable parameters of science and are dubious.\u00a0 However, recent research is suggesting that perhaps some fears are indeed transferable across generations.\u00a0 How can this be?
\n<\/span><\/p>\n

First, lets consider the life-cycle of a butterfly which commences as an egg laid by a mature butterfly.\u00a0 The egg hatches and a caterpillar (the larval stage) begins consumption of copious amounts of foliage (molting as he grows) in preparation for one of life’s most mysterious transitions.\u00a0 When the caterpillar is ready for its amazing metamorphosis, it cocoons itself into a chrysalis.\u00a0 During this phase the caterpillar essentially digests itself becoming a sack of ooze.\u00a0 It doesn’t transition from caterpillar into a butterfly by simply sprouting wings.\u00a0 Nope, it breaks down into a primordial soup and starts a remod from component cells called imaginal discs.\u00a0 These stem cells of sorts, comprised of just a small number of organized cells, ultimately reconfigure the sack of melted ooze into a fully functional butterfly.\u00a0 Although the imaginal discs have their beginnings in the egg stage, they remain essentially invisible but preparatory for the butterfly stage throughout the larval stage.\u00a0 They jump into rigorous reconstruction mode while in the chrysalis.\u00a0 This same process occurs in moths as well.<\/p>\n

\"Life<\/a>
Life Cycle of a Butterfly<\/figcaption><\/figure>\n

Life itself ceases for the caterpillar as it pupates in the chrysalis.\u00a0 It stops breathing, its heart stops beating: its muscles, skin and brain, legs, and antennae, all melt down, becoming liquid fodder for the resurrection.\u00a0 It’s not simply a transition – it’s a death and a rebirth.<\/p>\n

So, you may be asking, how is this relevant?\u00a0 Let’s consider some amazing research by Martha Weiss<\/a>, an Associate Professor in the Department of Biology at Georgetown University.\u00a0\u00a0 Her research focuses on evolutionary ecology, plant-animal interactions, butterfly and wasp learning, and caterpillar behavior.\u00a0 One of her studies<\/a> looked at whether learning during the caterpillar stage would make it across the pupal stage and be evidenced by the moth, despite the death and liquefication of the entire caterpillar.\u00a0 Such maintenance of memory was largely considered impossible.\u00a0 In her study, Dr. Weiss exposed caterpillars to a clearly distinguishable, but neutral odor, and then she paired the odor with a mild electric shock.\u00a0 Pretty quickly, after many repeated pairings,\u00a0 the caterpillars developed an aversion and a subsequent escape behavior, associated with the odor.\u00a0 They came to fear it.<\/p>\n

Following the pairing sessions and demonstration of learning, the caterpillars pupated.\u00a0 Just over one month later, as mature moths, when exposed to the conditioned odor, the moths demonstrated a strong aversion to what would normally be a neutral stimuli.\u00a0\u00a0\u00a0In this study there were also subjects that constituted the control group.\u00a0 The control moths were, when in the caterpillar stage, exposed to the odor but were not shocked.\u00a0 They never exhibited a definitive aversion to the odor (as caterpillars or moths).\u00a0 The caterpillars that were shocked, when presented with the odor, sustained the aversion even after pupating.\u00a0 The memory made it through the metamorphosis even though the caterpillar had died and the brain turned to goo in the meantime.<\/p>\n

This is remarkable – and suggests that memories are capable of being sustained across the death of the caterpillar and the rebirth (probably as a result of the data sustained in the imaginal disks).\u00a0 As amazing as this is, such memories were not transmitted from adult moths through to the egg and onto subsequent generations of\u00a0 caterpillars. \u00a0 So memories can transcend metamorphosis, but is there any evidence of the capacity to sustain memories across generational lines like that implied by the Indigo Girls?<\/p>\n

Researchers Brian Dias and Kerry Ressler<\/a> from Emory University School of Medicine, in Atlanta used a similar research design with mice, whereby adult mice were trained to have an aversive response to the aroma of cherry blossoms.\u00a0 They repeatedly paired this particular odor with electrical shocks and the mice subsequently learned, through classical conditioning, to fear the conditioned odor.\u00a0 Unlike moths, mice procreate through intercourse, gestation, and give live birth to baby mice.\u00a0 There is no metamorphosis, although gestation is a pretty amazing process in its own right.\u00a0 Anyways, Dias and Ressler breed the mice who had developed the aversion and tested to determine whether their offspring also feared the conditioned stimuli (aroma of cherry blossom).<\/p>\n

As it turns out, the offspring and their offspring evidenced an aversion to the cherry blossom odor despite never having been exposed to it or shocked.\u00a0 The fear appears to have been handed down across generations through a process called epigentics.\u00a0 Epigentic methylation results in changes in the DNA of the parent prior to conception that are then conferred to their offspring through sexual reproduction.<\/p>\n

Granted this has not been scientifically evidenced in humans as yet, but the implications of these findings are staggering. This suggests that DNA is not immutable: that in fact, what happens to a parent prior to conception, can alter his or her DNA, and that those changes can be handed down across multiple generations.\u00a0 Epigentics is well established and this process is increasingly understood.\u00a0 But evidence of trans-generational fear responses have not been likewise so well substantiated.\u00a0 This ability had been seriously doubted.\u00a0 It is now conceivable that a survivor of a plane crash may later produce offspring who themselves have a subsequent fear of flying.\u00a0 This may explain human phobic responses to spiders, snakes, heights, and other irrational fears that were previously unexplainable.<\/p>\n

This makes me think of my previous article titled Irrational Fear: It\u2019s Just an Alief.<\/a>\u00a0 In that article I wrote:<\/p>\n

Philosopher Tamar Gendler has coined the word \u201calief<\/a>\u201d to describe this cognitive phenomenon.\u00a0 She fashioned the word around the word \u201cbelief,\u201d which is a conscious manifestation of how we suppose things to be.\u00a0 An alief is a deep and powerful feeling of sorts that can and does play an important role in decision-making, but it is not<\/strong> based in reason or evidence.\u00a0 Beliefs can be more susceptible to such rational forces.\u00a0 But aliefs defy reason and exert powerful influence despite one\u2019s attempts to rationally dispel them.\u00a0 This voice is intuitive and its origins are outside your awareness.\u00a0 They typically appear in an attempt to facilitate self-preservation.<\/em><\/p><\/blockquote>\n

To call such fears an Alief just gives it a name.\u00a0 The underpinnings of such fears have been vague and speculative.\u00a0 The findings of Dias and Ressler provide a testable hypothesis for such phenomena.\u00a0 And now, when I stand at an intimidating precipice, I can speculate that my fear stems from an incident experienced by unfortunate kin rather than from random bad karma.<\/p>\n

References:<\/strong><\/span><\/p>\n

1. Blackiston DJ, Silva Casey E, Weiss MR (2008) Retention of Memory through Metamorphosis: Can a Moth Remember What It Learned As a Caterpillar?<\/a> PLoS ONE 3(3): e1736. doi:10.1371\/journal.pone.0001736<\/p>\n

2. Dias BG, Ressler KJ (2014). Parental olfactory experience influences behavior and neural structure in subsequent generations. <\/a><\/span>Nature Neuroscience (17):89\u201396.\u00a0<\/span><\/span><\/p>\n

3. Jabr F. (2012) How does a caterpillar turn into a butterfly? <\/a>Scientific American<\/p>\n

\u00a0<\/span><\/span>4. Radio Lab (2014)\u00a0 Black Box<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"

There is an Indigo Girls song called Galileo that references a fear of motion (00:01:19 into the song) and suggests that the source of this particular fear is from “some other fool across the ocean years ago [having] crashed his little airplane.”\u00a0 In the song, the means of transmission of this fear is reincarnation, which … <\/p>\n

Read more “Can Memories be Inherited?”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[82,63,38,1],"tags":[],"class_list":["post-3350","post","type-post","status-publish","format-standard","hentry","category-biology","category-genetics","category-memory","category-uncategorized"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p3mcUm-S2","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/geraldguild.com\/blog\/wp-json\/wp\/v2\/posts\/3350","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/geraldguild.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/geraldguild.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/geraldguild.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/geraldguild.com\/blog\/wp-json\/wp\/v2\/comments?post=3350"}],"version-history":[{"count":32,"href":"https:\/\/geraldguild.com\/blog\/wp-json\/wp\/v2\/posts\/3350\/revisions"}],"predecessor-version":[{"id":3800,"href":"https:\/\/geraldguild.com\/blog\/wp-json\/wp\/v2\/posts\/3350\/revisions\/3800"}],"wp:attachment":[{"href":"https:\/\/geraldguild.com\/blog\/wp-json\/wp\/v2\/media?parent=3350"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/geraldguild.com\/blog\/wp-json\/wp\/v2\/categories?post=3350"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/geraldguild.com\/blog\/wp-json\/wp\/v2\/tags?post=3350"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}