BBC Focus 02.2020

DISCOVERIES

Cat parasite makes infected

mice generally less anxious

It’sbeenknownforsomeyearsthat

whenthecatparasiteToxoplasmagondii

infectsrodentsit causesthemtolose

theirfearoffelinepredators,making

themeasiertocatch,andsoallowing

theparasitetocompleteitslifecycle

withincats.

However,accordingtonewresearch

carriedoutbya teamattheUniversityof

Geneva,theeffectofT.gondiiis widerin

reachandactuallyleadstoinfectedmice

showinga decreaseingeneralanxiety

anda reducedaversiontoa broadrange

ofthreats– notjustcats.

Theyfoundthatmiceinfectedwith

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weremorelikelytoexplorenovel

environments,interactwiththehands

oftheresearchers,andinvestigatethe

odoursofbobcats,foxesandguinea

pigsthantheirmoreskittish,uninfected

counterparts.

Toinvestigatewhatwasgoingon,the

team used a cutting-edge imaging system

toaccuratelymapthedistribution,size

andnumberofcystscausedbyT.gondii

inthebrainsoftheinfectedmice.They

foundparticularlyhighconcentrations

ofcystsinregionsinvolvedwith

processingvisualinformation,along

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tissuethroughoutthebrain.

“For 20 years,T.g o n d i ihasserved

asa textbookexamplefora parasitic

adaptivemanipulation,mainlybecause

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saidProfIvanRodriguez,a co-senior

authorofthestudy.“Wenowshow

thatthebehaviouralalterationdoes

notonlyaffectfearoffelinepredators

butthatmajorchangesoccurinthe

brainofinfectedmice,affectingvarious

behavioursandneuralfunction

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Theresearchersnowplantofurther

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altera rangeofbehaviouraltraitssuch as

anxiety, sociability or curiosity.

ZOOLOGY

ALAMY, GET T Y IMAGES ILLUSTRATIONS: TOM REDFERN

ALTRUISTS

Helpingotherscanreducepain,researchers

fromPekingUniversityhavefound.They

foundthatblooddonorsreportedlesspain

thanthoseundergoingbloodtests.Theyalso

foundthatpeoplecouldholdtheirhandsin icy

water forlongerif theyweretold it was to

benefit science.

TEADRINKERS

Drinkingteaat leastthreetimesa weekis

linkedwitha healthierlife,a teamat the

ChineseAcademyofMedicalSciencesfound.

Theirstudyofmorethan100,000people

foundthatteadrinkershada 20percentlower

riskofincidentheartdiseaseandstroke,anda

15 per cent decreased risk of all-cause death.

IMAGE-OBSESSEDMEN

Youngment akinganabolics teroidsin an

aempttogettherippedphysiquespopular

onsocialmediaandrealityTVshowscould

causea strainontheNHSin comingdecades,

saysa reportbyUKAnti-Doping.Steroidabuse

candamageorgansandincreasethe

likelihoodofheartdiseaseandstroke, the

researchers say.

MOVIESUPERFANS

Sometimesit reallyis beertomanageyour

expectations.A studybyresearchersatOhio

StateUniversityfoundthatviewersofStar

WarsVIII:TheLastJedif ilmwhowentinwith

highexpectationsbutweredisappointed

enjoyedit significantlylessthanthosegoing

in with lower expectations.

Bad month

Good month

Ratherunfairly,theToxoplasmagondiifelineparasitedoesn’ttend

to have an eect on cats, but it will make their prey more foolhardy