Tsarin juyayi na ɗan adam, mai tsananin rikitarwa, ya ƙunshi kusan neurons biliyan 100, wanda kuma ake kira ƙwayoyin jijiya. Neurons a cikin kwakwalwa na iya sadarwa ta hanyar synapses wanda ke watsa siginar jijiya daga neuron zuwa wani.

Dendrites gajeru ne, raƙuman rassan waɗannan neurons. Lallai, dendrites sune ɓangaren mai karɓa na neuron: galibi ana wakilta su azaman nau'in bishiyar da ke fitowa daga jikin sel ɗin neuronal. A zahiri, aikin ma'ana na dendrites zai kunshi tattara bayanai a matakin synapses wanda ya rufe su, kafin a tura su zuwa jikin sel na neuron. 

Kwayoyin jijiya sun sha bamban da sauran sel a jikin ɗan adam: a gefe ɗaya, ilimin halittar jikinsu yana da mahimmanci musamman a gefe guda, suna aiki da lantarki. Kalmar dendrite ta fito ne daga kalmar Helenanci Dendron, wanda ke nufin “itace”.

Sassan guda uku da suke yin neuron

Dendrites sune manyan sassan masu karɓa na neuron, wanda kuma ake kira sel jijiya. A zahiri, yawancin neurons sun ƙunshi manyan abubuwa uku:

• jikin tantanin halitta;
• iri biyu na kariyar salula da ake kira dendrites;
• axon. 

Jikin sel na neurons, wanda kuma ake kira soma, yana ɗauke da tsakiya da sauran gabobin jiki. Axon shine guda ɗaya, mai kauri, mai juzu'i wanda ke jagorantar motsawar jijiya zuwa wani neuron ko zuwa wasu nau'ikan nama. A zahiri, kawai aiki mai ma'ana na axon shine tuƙi, daga wuri ɗaya a cikin kwakwalwa zuwa wani, saƙon da aka sanya a cikin jerin abubuwan da za a iya aiwatar da su.

Me game da dendrites mafi daidai?

Tsarin bishiya yana fitowa daga jikin tantanin halitta

Waɗannan dendrites gajeru ne, masu nunin faifai, da manyan rassan rassan, suna yin wani nau'in bishiya da ke fitowa daga jikin sel neuronal.

Lallai dendrites ɗin sune sassan masu karɓa na neuron: a zahiri, murfin plasma na dendrites ya ƙunshi rukunin masu karɓa da yawa don ɗaure manzannin sunadarai daga wasu sel. An kiyasta radius na bishiyar dendritic a milimita ɗaya. A ƙarshe, maɓallan synaptic da yawa suna kan dendrites a wuraren da ke nesa da jikin sel.

Abubuwan da ke haifar da dendrites

Kowane dendrite yana fitowa daga soma ta wani mazugi wanda ya faɗaɗa cikin ƙirar cylindrical. Da sauri, sannan zai raba zuwa 'yar reshe biyu. Girman su ya fi na reshen iyaye girma.

Bayan haka, kowane ɗayan sakamakon da aka samu ya kasu kashi biyu, biyun, mafi kyau. Waɗannan ɓangarorin sun ci gaba: wannan shine dalilin da ya sa ƙwararrun masanan ilimin jijiyoyin jiki ke haifar da "bishiyar dendritic na neuron".

Ayyukan dendrites shine tattara bayanai a matakin synapses (sarari tsakanin neurons biyu) wanda ke rufe su. Sannan waɗannan dendrites zasu ɗauki wannan bayanin zuwa jikin sel na neuron.

Neurons suna da hankali ga abubuwan motsa jiki daban -daban, waɗanda suke juyawa zuwa siginar lantarki (waɗanda ake kira yuwuwar aikin juyayi), kafin su watsa waɗannan abubuwan na aiki zuwa wasu neurons, ƙwayar tsoka ko ma zuwa gland. Kuma hakika, yayin da a cikin gatari, motsin wutar lantarki ya bar soma, a cikin dendrite, wannan motsin lantarki yana yaduwa zuwa soma.

Nazarin kimiyya ya sa ya yiwu, godiya ga ƙananan wayoyin lantarki da aka dasa a cikin neurons, don kimanta rawar da dendrites ke da shi wajen watsa saƙonnin jijiya. Ya zama cewa, nesa da zama kawai kari mai wuce gona da iri, waɗannan tsarin suna taka muhimmiyar rawa wajen sarrafa bayanai.

Dangane da wannan binciken da aka buga a Nature, sabili da haka dendrites ba kawai za su kasance ƙaramin membrane mai sauƙi wanda ke da alaƙa da jigilar motsin jijiya zuwa axon ba: a zahiri ba za su zama masu shiga tsakani masu sauƙi ba, amma su ma za su sarrafa bayanai. Aikin da zai ƙara ƙarfin kwakwalwa. 

Don haka duk bayanan sun yi kama da juna: dendrites ba m ba ne, amma a hanya, minicomputers a cikin kwakwalwa.

Ayyukan mahaukaci na dendrites ana iya danganta su da dysfunctions da suka danganci neurotransmitters wanda ke ba su sha'awa ko, akasin haka, hana su.

Mafi sanannun waɗannan neurotransmitters sune dopamine, serotonin ko ma GABA. Waɗannan su ne ayyukan ɓarkewar ɓoyayyen ɓoyayyen su, wanda ya yi yawa ko akasin haka ya yi ƙasa sosai, ko ma an hana shi, wanda zai iya zama sanadin ɓarna.

Cututtukan da ke haifar da gazawa a cikin masu aikawa da jijiyoyin jini sune, musamman, cututtukan tabin hankali, kamar ɓacin rai, ɓacin rai ko schizophrenia.

Rashin gazawar hankali da ke da alaƙa da ƙarancin ƙa'idodin neurotransmitters sabili da haka, a ƙasa, zuwa aikin dendrites, yanzu ana samun ƙarin kulawa. Mafi yawan lokuta, sakamako mai fa'ida akan cututtukan cututtukan ƙwaƙwalwa za a samu ta hanyar haɗin gwiwa tsakanin maganin miyagun ƙwayoyi da saka idanu na nau'in ilimin halin kwakwalwa.

Akwai nau'ikan hanyoyin ilimin halin ɗabi'a da yawa: a zahiri, mai haƙuri na iya zaɓar ƙwararre tare da shi yana da ƙarfin gwiwa, saurara da kuma hanyar da ta dace da shi gwargwadon abin da ya gabata, gogewarsa, da buƙatun sa.

Akwai takamaiman hanyoyin kwantar da hankali-halayyar ɗabi'a, hanyoyin haɗin kai ko ma hanyoyin kwantar da hankali waɗanda ke da alaƙa da halin yanzu na psychoanalytic.

Sanin cutar tabin hankali, wanda saboda haka yayi daidai da gazawar tsarin juyayi wanda dendrites ke taka muhimmiyar rawa, likitan kwakwalwa zai yi. Sau da yawa zai ɗauki lokaci mai tsawo don yin ganewar asali.

A ƙarshe, yana da mahimmanci a san cewa mai haƙuri bai kamata ya ji tarko a cikin “lakabin” wanda zai nuna shi ba, amma ya kasance cikakken mutum ne, wanda kawai zai koyi koyon sarrafa yanayin sa. Kwararru, likitocin kwakwalwa da masu ilimin halin ƙwaƙwalwa, za su iya taimaka masa ta wannan hanyar.

An saita ranar gabatar da kalmar “neuron” a 1891. Wannan kasada, ainihin jikin mutum a farkon, ya fito musamman godiya ga baƙar launin launi na wannan sel, wanda Camillo Golgi ya aiwatar. Amma, wannan almara ta kimiyya, nesa da mai da hankali kawai kan tsarin tsarin wannan binciken, sannu a hankali ya sa ya yiwu a ɗauki cikin neuron a matsayin tantanin halitta kasancewar wurin zama na hanyoyin lantarki. Daga nan ya bayyana cewa waɗannan abubuwan da aka kayyade masu jujjuyawar, da kuma ayyukan kwakwalwa masu rikitarwa.

Ya kasance musamman daga shekarun 1950 cewa an yi amfani da kayan aikin biophysical masu inganci da yawa don nazarin neuron, a cikin infra-cellular sannan matakin matakin. Don haka, microscopy na lantarki ya ba da damar bayyana sararin ɓarna na synaptic, da kuma exocytosis na vesicles neurotransmitter a synapses. Daga nan ya yiwu a yi nazarin abubuwan da ke cikin waɗannan vesicles.

Bayan haka, wata dabara da ake kira “facin-matsa” ta sa ya yiwu, daga shekarun 1980, don yin nazarin bambance-bambancen da ake samu yanzu ta hanyar tashar ion guda ɗaya. Daga nan mun sami damar bayyana hanyoyin keɓaɓɓiyar ƙwayoyin jijiyoyin jijiyoyin jiki. Daga cikin su: sake jujjuyawar damar aiki a cikin bishiyoyin dendrite.

A ƙarshe, ga Jean-Gaël Barbara, masanin kimiyyar jijiyoyin jiki da masanin kimiyya, “sannu a hankali, neuron ya zama abin sabon wakilci, kamar sel na musamman tsakanin wasu, yayin da yake zama na musamman ta mahimmancin ma'anonin ayyukan hanyoyin sa".

Masana kimiyya Golgi da Ramon y Cajal an ba su lambar yabo ta Nobel a 1906 saboda aikin su da ya shafi tunanin neurons.