Scientists have shown that mazingira stress can affect normal development of neva system in worms who are approaching puberty
Scientists have been trying to understand how our genes (our genetic makeup) and different mazingira factors shape our mfumo wa neva wakati wa ukuaji wa mapema tunapokua. Ujuzi huu unaweza kuendeleza uelewa wetu wa matatizo mbalimbali ya neva ambayo husababishwa hasa wakati mizunguko ya kawaida ya neva katika kuvunjika kwa mfumo wetu wa neva. Katika utafiti uliochapishwa katika Nature, wanasayansi kutoka Chuo Kikuu cha Columbia wamechunguza mfumo wa neva wa minyoo ndogo ya uwazi (C. elegans) to elucidate understanding of how it shapes up. They show that stress caused by environmental factors can have a permanent intense effect on connections taking place in the nervous system which is still developing. In their experiment they made male worms undergo starvation just before the worms were to undergo sexual maturation with an aim to stunt their puberty. Exposure to external stress, specifically starvation, even a few days before sexual maturation affected wiring patterns of critical neuronal circuits in worm’s nervous system thus preventing normal changes to take place. The rewiring program of their nervous system was basically interrupted. Once these ‘alisisitiza’ males underwent puberty and became adult, immature circuits still remained in their nervous system causing them to continue to act immature. Their Immaturity was judged by observing that stressed adult male worms showed high sensitivity to a toxic chemical called SDS compared to normal adult males. The stressed worms also spent limited time with other hermaphrodite worms and had difficulties in mating.
Wanasayansi walifanya ugunduzi huu muhimu wakati minyoo fulani waliachwa bila kutunzwa kwa wiki kadhaa na hawakupewa chakula. Hii ilisababisha kusitishwa kwa ukuaji wa kawaida wa minyoo na wakaingia katika hali inayoitwa 'dauer state'. Hali hii ni kama kusimamishwa kwa muda kwa ukuaji wa kawaida wa kiumbe. Katika kesi ya minyoo, wakati minyoo wachanga walihisi aina yoyote ya dhiki, pause ya muda hutokea katika ukuaji wao wa kawaida kwa miezi na baadaye mara tu dhiki inapoisha ukuaji wao huanza tena. Kwa hiyo, baada ya mkazo wa njaa kupita, minyoo walirudi katika mazingira yao ya kawaida na waliendelea kukomaa na kuwa watu wazima. Baada ya kuchunguza mfumo wa neva wa minyoo ambayo sasa ni watu wazima, ilionekana kwamba baadhi ya miunganisho michanga katika mikia ya minyoo dume ilihifadhiwa ambayo ingeondolewa (au kupogolewa) wakati wa kukomaa kingono. Watafiti walichunguza zaidi kueleza kuwa 'hali ya dauer' ilisababishwa na mfadhaiko wa njaa na wala si mfadhaiko mwingine wowote. Mkazo huo ulisababisha upangaji upya wa michoro zao za waya. Madhara ya kinyume ya neurotransmitters mbili - serotonini na octopamine - kudhibiti kupogoa kwa nyaya. Minyoo iliyosisitizwa ilikuwa na kiasi kikubwa cha octopamine ambayo ilizuia uzalishaji wa serotonin. Ikiwa serotonini ilitolewa kwa wanaume wachanga wakati wa dhiki, basi kupogoa kwa kawaida kulifanyika na watu wazima huanza kuonyesha majibu ya kukomaa kwa SDS. Kwa kulinganisha wakati octopamine ilitolewa kwa wanaume wachanga, hii ilizuia kupogoa kwa mzunguko. Utafiti unapendekeza kuwa mfadhaiko unaweza kuwa na athari inayowezekana kwa mabadiliko katika mfumo wa neva wakati maendeleo ya mapema yanapofanyika. Serotonini ya neurotransmitter inahusishwa na hali ya akili ya unyogovu kwa wanadamu.
Je, uwezekano huu unaweza kuwa kweli kwa wanadamu pia wakati huo? Sio moja kwa moja kwa wanadamu kwani tuna mfumo wa neva mkubwa zaidi na ngumu zaidi ikilinganishwa na wanyama. Walakini, minyoo ni viumbe rahisi lakini vyema vya kusoma na kuchambua mifumo ya neva. Watafiti wakuu wa utafiti huu wameanzisha mradi uitwao ceNGEN ambao kupitia huo watapanga muundo wa vinasaba na shughuli za kila neuroni katika mfumo wa neva wa C. elegans worm ambao ungesaidia kuelewa katika uundaji wa mfumo wa neva kwa undani zaidi na ushirikiano unaowezekana kati ya mtu. maumbile na uzoefu wa mtu.
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Chanzo (s)
Bayer EA na Hobert O. 2018. Uzoefu wa zamani hutengeneza wiring za nyuroni za dimorphic kupitia uashiriaji wa monoaminergic. Nature. https://doi.org/10.1038/s41586-018-0452-0
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