the origin and nature of emotions-第27节

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　production　of　fever。

That　the　stimulation　of　the　brain…cells　without　gross　activity　of　the　skeletal　muscles　and　without　infection　can　produce　heat　is　shown　as　follows：

（_a_）　Fever　is　produced　when　animals　are　subjected　to　fear　without　any　consequent　exertion　of　the　skeletal　muscles。

（_b_）　The　temperature　of　the　anxious　friends　of　patients　will　rise　while　they　await　the　outcome　of　an　operation　（Fig。　63）。

（_c_）　The　temperature　and　pulse　of　patients　will　rise　as　a　result　of　the　mere　anticipation　of　a　surgical　operation　（Fig。　64）。

（_d_）　There　are　innumerable　clinical　observations　as　to　the　effect　of　emotional　excitation　on　the　temperature　of　patients。　A　rise　of　a　degree　or　more　is　a　common　result　of　a　visit　from　a　tactless　friend。　　There　is　a　traditional　Sunday　increase　of　temperature　in　hospital　wards。　　Now　the　visitor　does　not　bring　and　administer　more　infection　to　the　patient　to　cause　this　rise；　and　the　rise　of　temperature　occurs　even　if　the　patient　does　not　make　the　least　muscular　exertion　as　a　result　of　the　visit。　I　once　observed　an　average　increase　of　one　and　one…eighth　degrees　of　temperature　in　a　ward　of　fifteen　children　as　a　result　of　a　Fourth　of　July　celebration。

Is　the　contribution　of　the　brain　to　the　production　of　heat　due　to　the　conversion　of　latent　energy　directly　into　heat；　or　does　the　brain　produce　heat　principally　by　converting　its　latent　energy　into　electricity　or　some　similar　form　of　transmissible　energy　which；　through　nerve　connections；　stimulates　other　organs　and　tissues；　which　in　turn　convert　their　stores　of　latent　energy　into　heat？

According　to　Starling；　when　the　connection　between　the　brain　and　the　muscles　of　an　animal　is　severed　by　curare；　by　anesthetics；　by　the　division　of　the　cord　and　nerves；　then　the　heat…producing　power　of　the　animal　so　modified　is　on　a　level　with　that　of　cold…blooded　animals。　With　cold　the　temperature　falls；　with　heat　it　rises。　　Such　an　animal　has　no　more　control　over　the　conversion　of　latent　energy　into　heat　than　it　has　over　the　conversion　of　latent　energy　into　motion。

Electric　stimulation　done　over　a　period　of　time　causes　brain…cell　changes；　and　electric　stimulation　of　the　muscles　causes　a　rise　in　temperature。


Summary　of　Brain…cell　Studies

In　our　crossed　circulation　experiments　we　found　that　neither　waste　products　nor　metabolic　poisons　could　be　considered　the　principal　cause　of　the　brain…cell　changes。　　We　found　that　in　the　production　both　of　muscular　action　and　of　fever　there　were　brain…cell　changes　which　showed　a　quantita…tive　relation　to　the　temperature　changes　or　to　the　muscular　work　done。　　We　observed　that　under　deep　morphinization　the　febrile　response　or　the　muscular　work　done　was　either　diminished　or　eliminated　and　that　the　brain…cell　changes　were　correspondingly　diminished　or　eliminated。　　We　found　also　that　brain…cell　changes　and　muscular　work　followed　electric　stimulation　alone。　I　conclude；　therefore；　that　the　brain…cell　changes　are　work　changes。

We　shall　next　consider　other　organs　of　the　kinetic　system　in　their　relation　to　muscular　activity；　to　emotion；　to　consciousness；　to　sleep；　to　hibernation；　and　to　heat　production。


The　Adrenals

In　our　extensive　study　of　the　brain　in　its　relation　to　the　production　of　energy　and　the　consequent　exhaustion　caused　by　fear　and　rage；　by　the　injection　of　foreign　proteins；　of　bacterial　toxins；　and　of　strychnin；　by　anaphylaxis；　by　the　injection　of　thyroid　extract；　of　adrenalin；　and　of　morphin；　we　found　that；　with　the　exception　of　morphin；　each　of　these　agents　produced　identical　changes　in　the　brain…cells。　As　we　believed　that　the　adrenals　were　intimately　associated　with　the　brain　in　its　activities；　we　concluded　that　the　adrenals　also　must　have　been　affected　by　each　of　these　agents。　To　prove　this　relation；　we　administered　the　above…mentioned　stimuli　to　animals　and　studied　their　effects　upon　the　adrenals　by　functional；　histologic；　and　surgical　methods；　the　functional　tests　being　made　by　Cannon's　method。

Functional　Study　of　the　Adrenals。Our　method　of　applying　the　Cannon　test　for　adrenalin　was　as　follows：　　（_a_）　The　blood　of　the　animals　was　tested　before　the　application　of　the　stimulus。　If　this　test　was　negative；　then　（_b_）　the　stimulus　was　applied　and　the　blood　again　tested。　　If　this　second　test　was　negative；　a　small　amount　of　adrenalin　was　added。　　If　a　positive　reaction　was　then　given；　the　negative　result　was　accepted　as　conclusive。　（_c_）　If　the　control　test　was　negative；　then　the　stimulus　was　given。　If　the　blood　after　stimulation　gave　a　positive　result　for　adrenalin；　a　second　test　of　the　same　animal's　blood　was　made　twenty…five　minutes　or　more　later。　　If　the　second　test　was　negative；　then　the　positive　result　of　the　first　test　was　accepted　as　conclusive。

We　have　recorded　66　clear…cut　experiments　on　dogs；　which　show　that　after　fear　and　rage；　after　anaphylaxis；　after　injections　of　indol　and　skatol；　of　leucin　and　creatin；　of　the　toxins　of　diphtheria　and　colon　bacilli；　of　streptococci　and　staphylococci；　of　foreign　proteins；　and　of　strychnin；　the　Cannon　test　for　adrenalin　was　positive。　The　test　was　negative　after　trauma　under　anesthesia；　and　after　intravenous　injections　of　thyroid　extract；　of　thyroglobin；　and　of　the　juices　of　various　organs　injected　into　the　same　animal　from　which　the　organs　were　taken。　　Placental　extract　gave　a　positive　test。　The　test　was　sometimes　positive　after　electric　stimulation　of　the　splanchnic　nerves。　　On　the　other　hand；　if　the　nerve　supply　to　the　adrenals　had　been　previously　divided；　or　if　the　adrenals　had　been　previously　excised；　then　the　Cannon　test　was　negative　after　the　administration　of　each　of　the　foregoing　adequate　stimuli。　Blood　taken　directly　from　the　adrenal　vein　gave　a　positive　result；　but　under　deep　morphinization　the　blood　from　the　adrenal　vein　was　negative；　and　under　deep　morphinization　the　foregoing　adequate　stimuli　were　negative。

In　brief；　the　agencies　that　in　our　brain…cell　studies　were　found　to　cause　hyperchromatism　followed　by　chromatolysis　gave　positive　results　in　the　Cannon　test　for　adrenalin　（Fig。　62）。　The　one　agent　which　was　found　to　protect　the　brain　against　changes　in　the　Nissl　substance　morphingave　a　negative　result　in　the　Cannon　test　for　adrenalin。　After　excision　of　the　adrenals；　or　after　division　of　their　nerve　supply；　all　Cannon　tests　for　adrenalin　were　negative。

Histologic　Study　of　the　Adrenals。Histologic　studies　of　the　adrenals　after　the　application　of　the　adequate　stimuli　which　gave　positive　results　to　the　Cannon　test　for　adrenalin　are　now　in　progress；　and　thus　far　the　histologic　studies　corroborate　the　functional　tests。

In　hibernating　woodchucks；　the　cells　of　the　adrenal　cortex　were　found　to　be　vacuolated　and　shrunken。　　In　one　hundred　hours　of　insomnia；　in　surgical　shock；　in　strong　fear；　in　exhaustion　from　fighting；　after　peptone　injections；　in　acute　infections；　the　adrenals　undergo　histologic　changes　characteristic　of　exhaustion　（Figs。　66　to　67）。

We　have　shown　that　brain　and　adrenal　activity　go　hand　in　hand；　that　is；　that　the　adrenal　secretion　activates　the　brain；　and　that　the　brain　activates　the　adrenals。　　The　fundamental　question　which　now　arises　is　this：　　Are　the　brain　and　the　adrenals　interdependent？　A　positive　answer　may　be　given　to　this　question；　for　the　evidence　of　the　dependence　of　the　brain　upon　the　adrenals　is　as　clear　as　is　the　evidence　of　the　dependence　of　the　adrenals　upon　the　brain。　（1）　After　excision　of　the　adrenals；　the　brain…cells　undergo　continuous　histologic　and　functional　deterioration　until　death。　During　this　time　the　brain　progressively　loses　its　power　to　respond　to　stimuli　and　there　is　also　a　progressive　loss　of　muscular　power　and　a　diminution　of　body　temperature。　（2）　｛illust。　caption　=　FIG。　　66。In　our　crossed　circulation　experiments　we　found　that　adrenalin　alone　could　cause　increased　brain　activity；　while　histologically　we　know　that　adrenalin　alone　causes　an　increase　of　the　Nissl　substance。　　An　animal；　both　of　whose　adrenals　had　been　excised；　showed　no　hyperchromatism　in　the　brain…cells　after　the　injection　of　strychnin；　toxins；　foreign　proteins；　etc。　（3）　When　the　adrenal　nerve　supply　is　divided　（Cannon…Elliott）；　then　there　is　no　increased　adrenal　activity　in　response　to　adequate　stimuli。

From　these　studies　we　are　forced　to　conclude　not　only　that　the　brain　and　adrenals　are　interdependent；　but　that　the　brain　is　actually　more　dependent　upon　the　adrenals　than　the　adrenals　upon　the　brain；　since　the　brain　deteriorates　progressively　to　death　without　the　adrenals；　while　the　adrenal　whose　connection　with　the　brain　has　been　broken　by　the　division　of　its　nerve　supply　will　still　produce　sufficient　adrenalin　to　support　life。

From　the　strong　affinity　of　the　brain…cells　for　adrenalin　which　was　manifested　in　our　experiments　we　may　strongly　suspect　that　the　Nissl　substance　is　a　volatile；　extremely　unstable　combination　of　certain　elements　of　the　brain…cells　and　adrenalin；　because　the　adrenals　alone　do　not　take　the　Nissl　stain　and　the　brain　deprived　of　adrenalin　also　does　not　take　Nissl　stain。　　The　consumption　of　the　Nissl　substance　in　the　brain…cells　is　lessened　or　prevented　by　morphin；　as　is　the　output　of　adrenalin；　and　the　consumption　of　the　Nissl　substance　is　also　lessened　or　prevented　by　nitrous　oxid。　But　morphin　does　not　prevent