TelencephalonTelencephalonWhite matterWhite matter. . Basal gangliaBasal ganglia

Telencephalic white matter

Projection fibersCorona radiata

Commissural fibers

Corpus callosumrostrum, genu, trunkus, splenium

Commissura anteriorCommissura fornicis

Association fibers

Fibrae arcuatae brevesFibrae arcuatae longi

Association fibersAssociation fibers

1. F1. Fasciculus longitudinalis superiorasciculus longitudinalis superior2. 2. Fasciculus longitudinalis inferiorFasciculus longitudinalis inferior33. . CCingulumingulum4. Fasciculus uncinatus4. Fasciculus uncinatus5. Fibrae arcuatae brevae5. Fibrae arcuatae brevae

1. Fasciculus longitudinalis superior 3. Fasciculus uncinatus 2. Fasciculus occipitofrontalis 4. Fasciculus perpendicularis

inferior occipitalis

Association fibersAssociation fibers ((lateral aspectlateral aspect))

1. Cingulum 4. Fasciculus occipitofrontalis superior2. Fasciculus uncinatus 5. Fasciculus perpendicularis occipitalis3. Fasciculus longitudinalis inferior

Asociation fibersAsociation fibers ((medial aspectmedial aspect))

Speech areasSpeech areas

Commissural fibersCommissural fibersCCorpus callosumorpus callosum symmetrical areas of the hemispheressymmetrical areas of the hemispheres splenium, corpus, genu, rostrumsplenium, corpus, genu, rostrumCCommissura anteriorommissura anterior temporal lobestemporal lobes olfatory bulbsolfatory bulbs

CCommisssura posteriorommisssura posterior leftleft and right parts ofand right parts of tectumtectum & &

tegmentum of midbraintegmentum of midbrainCommissura fornicisCommissura fornicis between both crura of fornixbetween both crura of fornix

CCorpus callosumorpus callosum - - forceps minorforceps minor

- forceps major- forceps major- tapetum- tapetum

Commissura anteriorCommissura anterior - pars anterior- pars anterior

-- pars posteriorpars posterior Commissura anteriorCommissura anterior((frontal sectionfrontal section))

Commissural fibers

1. Corpus callosum 3. Forceps minor2. Commissura anterior 4. Forceps major

Lateralisation of functionsLateralisation of functions

А. А. Dominant hemisphreDominant hemisphre - - mention mention the stimulusthe stimulus

BB. . Nondominant hemisphereNondominant hemisphere -- points the stimuluspoints the stimulusCC. . AnomiaAnomia – – can not name stimuli on can not name stimuli on

the left handthe left handDD.. AlexiaAlexia in the left visual fieldsin the left visual fieldsEE.. TestTest – – hybrid facehybrid face - -

the patient answers manthe patient answers man, , but but point the womanpoint the woman

SSplit brain syndromeplit brain syndrome

Projection fibersProjection fibers

11. . Crus anteriorCrus anteriorbetweenbetween nucl. caudatus и nucl. lentiformis nucl. caudatus и nucl. lentiformis

-- stripes of grey matterstripes of grey matter

22. . GenuGenu33. . Crus posteriorCrus posterior

Pars thalamolentiformisPars thalamolentiformis- betweenbetween thalamus thalamus && nucl. lentiformis nucl. lentiformis

Pars retrolentiformisPars retrolentiformisPars sublentiformisPars sublentiformis

Capsula internaCapsula interna

Capsula interna

1. Tractus corticonuclearis2. Tractus corticospinalis3. Fibrae corticothalamicae4. Fibrae thalamocorticales5. Radiatio acustica6. Radiatio optica

14. Fibrae corticorubrales

White matter (frontal section)

1. Corpus callosum2. Capsula interna3. Fasciculus occipitofrontalis superior4. Fasciculus longitudinalissuperior5. Fasciculus occipitofrontalisinferior6. Cingulum7. Fasciculus uncinatus8. Fasciculus longitudinalisinferior

Basal gangliaBasal ganglia

LocationLocation

Section through the base of hemisphere exposesSection through the base of hemisphere exposes

aa. . Paired nuclear massesPaired nuclear masses within the hemisphereswithin the hemispheres..

b. Surounded by white matter b. Surounded by white matter (capsula interna, (capsula interna,

capsula externa, capsula extrema)capsula externa, capsula extrema)

Components of theComponents of the Basal gangliaBasal ganglia

Corpus StriatumCorpus Striatum Striatum ----- Caudate Nucleus & PutamenStriatum ----- Caudate Nucleus & Putamen Pallidum ----- Globus Pallidus (GP)Pallidum ----- Globus Pallidus (GP)Substantia NigraSubstantia Nigra Pars Compacta (SNc)Pars Compacta (SNc) Pars Reticulata (SNr)Pars Reticulata (SNr)Subthalamic Nucleus (STN)Subthalamic Nucleus (STN)Ventral Striatum Ventral Striatum ии Ventral Pallidum Ventral Pallidum Nucleus Accumbens SeptiNucleus Accumbens Septi Noncholiergic part ofNoncholiergic part of Substantia Innominata Substantia Innominata

Basal gangliaBasal ganglia ComponentsComponents

STRIATUMSTRIATUM

Nucleus CaudatusNucleus Caudatus Caput, (Corpus), CaudaCaput, (Corpus), Cauda Caudolenticular bridges of grey matterCaudolenticular bridges of grey matterPutamenPutamenStriatum VentralisStriatum Ventralis: : Nucleus Accumbens (Septi)Nucleus Accumbens (Septi)

Basal ganglia ComponentsBasal ganglia Components

Striatal CompartmentsStriatal Compartments (Mosaic or Modular Organization)(Mosaic or Modular Organization)

1. 1. Striosome (Patches)Striosome (Patches) - 10-20% of total striatal mass- 10-20% of total striatal mass - low acetylcholinesterase (AchE) activity- low acetylcholinesterase (AchE) activity - high substance P (SP), neurotensin (NT), tyrosine hydroxylase- high substance P (SP), neurotensin (NT), tyrosine hydroxylase - high expression of D- high expression of D11 dopamine receptor dopamine receptor - high opiate receptor- high opiate receptor

2. 2. MatrixMatrix - high acetylcholinesterase (AchE) activity- high acetylcholinesterase (AchE) activity - high somatostatin (SRIF) activity- high somatostatin (SRIF) activity - high D- high D22 dopamine receptor dopamine receptor

Basal Ganglia Components Basal Ganglia Components

Traditional Concepts of Traditional Concepts of Basal GangliaBasal Ganglia

Corpus StriatumCorpus Striatum

Caudate NucleusCaudate Nucleus

Lenticular Nucleus PutamenLenticular Nucleus Putamen

Globus Pallidus Globus Pallidus PaleostriatumPaleostriatum Pallidum Pallidum

Corpus Amygdaloideum Corpus Amygdaloideum ArchistriatumArchistriatum

NeostriatumNeostriatum Striatum Striatum

Basal Ganglia Introduction Basal Ganglia Introduction

1. Putamen1. Putamen2. Tail of caudate 2. Tail of caudate

nucleusnucleus3. Caudatolenticular 3. Caudatolenticular

gray bridgegray bridge4. Amygdaloid body4. Amygdaloid body5. thalamus5. thalamus

Lateral surface Lateral surface of basal gangliaof basal ganglia

1. head of 1. head of caudate nuceluscaudate nucelus2. body of 2. body of caudate nuceluscaudate nucelus3. caudatolenticular 3. caudatolenticular gray bridgegray bridge4. putamen4. putamen5. tail of 5. tail of caudate nucleus caudate nucleus

6. external segment of 6. external segment of globus pallidus globus pallidus

7. internal segment of 7. internal segment of globus pallidusglobus pallidus

8. amygdaloid body8. amygdaloid body9. nucleus accumbens 9. nucleus accumbens

septisepti

Medial surface of basal gangliaMedial surface of basal ganglia

PutamenPutamenGlobus pallidusGlobus pallidus external segmentexternal segment internal segmentinternal segmentSubthalamic NucleusSubthalamic NucleusSubstantia nigraSubstantia nigra

Internal capsuleInternal capsule

Components ofComponents ofBasal GangliaBasal Ganglia

Input Portion Input Portion

STRIATUM STRIATUM

(Caudate Nucleus and Putamen)(Caudate Nucleus and Putamen)

Output PortionOutput Portion

1. 1. PALLIDUM PALLIDUM (Globus Pallidus)(Globus Pallidus)

2. 2. SNr SNr (Substantia Nigra, Pars Reticulata)(Substantia Nigra, Pars Reticulata)

Basal Ganglia Connections

Basal ganglia ConnectionsBasal ganglia Connections

А. Striatum (nucl. caudatus + putamen)

1. Afferent fibersа. Cortex (sensimotor – gyrus paracentralis)b. Thalamus – nucl. centromedianum, NVL, NVAc. Substantia nigrad. Nuclei raphe

2. Efferent fibersa. Pallidum [ [striopallidal]b. SN SN [strionigral]

B. Globus pallidus (pallidum) 1. Afferent fibers

а. Striatum (striopallidal fibers)b. Nucleus subthalamicus (fasciculus subthalamicus)c. Cerebral cortexd. Substantia nigrae. Nuclei raphe

2. Efferents fibersa. Common final pathway to thalamusb. Ansa lenticularis, fasciculus lenticularis, fasciculus subthalamicus

Basal ganglia ConnectionsBasal ganglia Connections

Basal ganglia ConnectionsBasal ganglia Connections

Basal Ganglia (Main Motor Circuit) ConnectionsBasal Ganglia (Main Motor Circuit) Connections

SupplementarySupplementaryMotor AreaMotor Area

(SMA)(SMA)

PrimaryPrimaryMotor AreaMotor Area

(M I)(M I)

THALAMUSTHALAMUS(VLo, VApc, CM)(VLo, VApc, CM)

STRIATUMSTRIATUM(Putamen)(Putamen)

PALLIDUMPALLIDUM(GPi)(GPi)

pyramidalpyramidal tracttract

LMNLMN

ansaansalenticularislenticularis

lenticularlenticularfasciculusfasciculus

SMASMA (supplementary motor area)(supplementary motor area)

Basal Ganglia and Pyramidal TractBasal Ganglia and Pyramidal Tract

upper motor neuronupper motor neuron

UMNUMN

lower motor neuronlower motor neuron

LMNLMN

pyramidalpyramidal tracttract BASALBASAL

GANGLIAGANGLIA CIRCUITCIRCUIT

Functional roleFunctional role

Regulate the motor activityRegulate the motor activity byby intrinsic and extrisic feed-back circuitsintrinsic and extrisic feed-back circuits

Role in the control of movementsRole in the control of movements

Suppress the motor toneSuppress the motor tone

Suppress the excesive and unnecessary movementsSuppress the excesive and unnecessary movements

Signs in lesion of basal gangliaSigns in lesion of basal ganglia

1. 1. Akinesia & bradykinesiaAkinesia & bradykinesia - - difficulty in initiation and difficulty in initiation and cessation of movementcessation of movement

2. 2. RigidityRigidity of musclesof muscles

3. 3. Involutary movementsInvolutary movements ( (hyperkinesiahyperkinesia) – ) – tremortremor, , ticstics, , balismbalism, , choreachorea, , atetosisatetosis, , distoniadistonia

Basal Ganglia Basal Ganglia Functional Consideration Functional Consideration

Functional ConsiderationFunctional Consideration

1. 1. Selection Selection of “Preprogramed (learned) motor plans”of “Preprogramed (learned) motor plans” Basal Gangla Circuit ---- Basal Gangla Circuit ---- Selection MechanismSelection Mechanism Selection Inability -------- Selection Inability -------- Akinesia and HypokinesiaAkinesia and Hypokinesia Faulty Selection ----------- Faulty Selection ----------- HyperkinesiaHyperkinesia

2. 2. Generation (learning) Generation (learning) of motor programsof motor programs Programming of several Programming of several motor fragments motor fragments intointo complex motor routinescomplex motor routines Cerebral Palsy Cerebral Palsy ------------- Disordered motor program ------------- Disordered motor program

SYDENHAM’S CHOREASYDENHAM’S CHOREA

- Complication of- Complication of Rheumatic FeverRheumatic Fever- Fine, disorganized , and - Fine, disorganized , and random movements ofrandom movements of extremities, face andextremities, face and tonguetongue- Accompanied by - Accompanied by Muscular HypotoniaMuscular Hypotonia- Typical exaggeration of- Typical exaggeration of associated movements associated movements during voluntary activityduring voluntary activity- Usually recovers- Usually recovers spontaneously spontaneously in 1 to 4 monthsin 1 to 4 months

Clinical FeatureClinical Feature

Principal Pathologic Lesion: Principal Pathologic Lesion: Corpus StriatumCorpus Striatum

Clinical FeatureClinical Feature

Principal Pathologic Lesion:Principal Pathologic Lesion: Corpus Striatum (esp. caudate nucleus)Corpus Striatum (esp. caudate nucleus) and Cerebral Cortexand Cerebral Cortex

- Predominantly - Predominantly autosomal dominantlyautosomal dominantly inherited chronic fatal diseaseinherited chronic fatal disease (Gene: chromosome 4)(Gene: chromosome 4)- Insidious onset: Usually 40-50- Insidious onset: Usually 40-50- Choreic movements in onset- Choreic movements in onset- Frequently associated with- Frequently associated with emotional disturbancesemotional disturbances- Ultimately, grotesque gait and sever- Ultimately, grotesque gait and sever dysarthria, progressive dementiadysarthria, progressive dementia ensues.ensues.

HUNTINGTON’S CHOREAHUNTINGTON’S CHOREA