1

Gross Anatomy of the Brain

Midbrain

Pons

Pyramid

Basispedunculi

Optic nerve (II)Optic chiasmOptic tract

Oculomotor nerve (III)Trochlear nerve (IV)

Trigeminal nerve (V)Abducens nerve (VI)Facial and intermediatenerves (VII)Vestibulocochlearnerve (VIII)Glossopharyngeal (IX)and vagus nerves (X)Hypoglossal nerve (XII)Accessory nerve (XI)Pyramidal decussation

Cervicalventralroots

Diencephalon

CRANIAL NERVES

2

PyramidOlive

Basis pedunculi

Cerebellar peduncles:SuperiorMiddle

Inferior

Opticnerve (II)

Lateral geniculate body

Oculomotornerve (III)

Trochlear nerve (IV)

Trigeminalnerve (V)

Abducens nerve (VI)

Facial and intermediatenerves (VII) Vestibulocochlear

nerve (VIII)

Glossopharyngeal (IX)and vagus nerves (X)

Hypoglossal nerve (XII)

Cervicalventralroots

Inferior colliculus

Spinal accessorynerve (XI)

Midbrain

Pons

Medulla

Diencephalon

CRANIAL NERVES

Special visceral Generalsomatic

General and special visceralGeneral somatic

Special somatic

Midbrain

AfferentMotor

Pons

Medulla

Spinal cord

Generalvisceral

Hypoglossal nucleus (N. XII)

Dorsal motor nucleusof vagus (N. X)

Accessory nucleus (N. XI)Spinal trigeminalnucleus (V, VII, IX, X)

Solitary nucleus(N. VII, IX, X)

Principal sensorytrigeminal nucleus (N. V)

III

VII

IX

XXIIIX

VI VIIIVIII

IV

III

V

IX, X

VII

V

V

V, VII,IX, X

XI

Vestibular nuclei(N. VIII)

Cochlear nucleus(N. VIII)

Edinger-Westphalnucleus (N. III)

Oculomotornucleus (N. III)

Trochlearnucleus (N. IV)

Trigeminal motornucleus (N. V)

Abducens nucleus (N. VI)Facial motornucleus (N. VII)

Salivatorynucleus

Nucleus ambiguus (N. IX, X)

Superior (N. VII)Inferior (N. IX)

Mesencephalictrigeminalnucleus (N. V)

CRANIAL NERVE NUCLEI

Special somaticafferent (VIII)

Afferent:Somatic

Sulcuslimitans

Visceral

General somaticafferent (V, VII, IX, X)General and specialvisceral afferent(VII, IX, X)General visceralmotor (III, VII, IX, X)

General somaticmotor (III, IV, VI, XII)

Special visceral motor(V, VII, IX, X, XI)

VisceralSomatic

CRANIAL NERVE NUCLEI

3

Edinger-Westphalnucleus (III)

Section through superior colliculus

Section through inferior colliculus

Mesencephalictrigeminalnucleus (V)

Trochlearnucleus (IV)

Mesencephalictrigeminal nucleus (V)

Oculomotornucleus (III)

CRANIAL NERVE NUCLEI

Section through middle cerebellar peduncle

Section through cochlear nuclei and the trapezoid body

Vestibularnuclei (VIII)

Spinaltrigeminalnucleus (V)

Abducens nucleus (VI)Cochlearnuclei (VIII)

Mesencephalictrigeminalnucleus (V)Vestibularnuclei (VIII)

Principal sensorytrigeminalnucleus (V)

Motortrigeminalnucleus (V)

Facial motornucleus (VII)

CRANIAL NERVE NUCLEI

Parvocellular

MagnocellularML

MLF

ICP

PYR

BRAIN STEM RETICULAR FORMATION

4

BRAIN STEM DEVELOPMENT

A B

C

D

Sulcus limitans

Alar plate

Basal plate

Special somaticafferent

Generalvisceral motorSpecialvisceral motorGeneral somaticmotor

Solitary nucleus(VII, IX, X)

Hypoglossalnucleus (XII)

Dorsal motornucleus ofvagus (X)

Nucleusambiguus (X)

General and specialvisceral afferentGeneral somaticafferent

Vestibular nucleus (VIII)

Spinaltrigeminalnucleus(V, VII, IX, X)

BRAIN STEM DEVELOPMENT

Motorareas

Non-motorareas

Brain stemmotor nuclei

Basalganglia

Motorneurons

Movement

Spinalinterneurons

Cerebellum

MOVEMENT CONTROL

5

Medial brain stempathways

Reticular andvestibularnuclei

B Lateral corticospinal tract A Ventral corticospinal tract

Rubrospinaltract

Pyramidaldecussation

Lateral corticospinaltract

4

6

Ventralcorticospinaltract

Red nucleus(magnocellular part)

Internal capsuleInternal capsule

3,1,2

4

6

MOVEMENT CONTROL

Cerebral cortex

Ascending dorsal column – medial lemniscal pathway to primary sensory cortexSomatic sensory cortex(postcentral gyrus)Toe

Lateralsulcus

Internalcapsule

Thalamus Ventral posteriorlateral nucleus

Medial lemniscus

Medial lemniscus

Gracile nucleus

Gracile fascicleCuneate fascicleDorsal root

ganglion

Medulla

Spinal cord

Cuneate nucleusSpinal trigeminalnucleus

Sensory decussation

Medulla

Pons

Midbrain

Third ventricle

LegTrunk

Forearm andhand area

Face

SENSORYCONTROL

Midbrain

Sympatheticdivision

Projections ofsympatheticdivision

Projections ofparasympatheticdivision

Parasympatheticdivision

Superior cervicalganglion

Ciliary ganglion

Otic ganglion

Esophagusand lungs

Stomach

Pancreas

Smallintestine

Large intestine,rectum

BladderPelvic nerveleading topelvic ganglia

Reproductiveorgans

Adrenal medulla

Bronchi

Heart

Eye

Lacrimal andsalivary glands

Pterygopalatine and submaxillary ganglion

III

VII

IX

X

Superiormesentericganglion

Sypatheticchain

Inferiormesentericganglion

Middle cervicalganglion

Inferior cervicalganglion

Celiac ganglion

PonsMedulla

Piloerectormuscle

Artery

Sweatglands

CervicalCranialnerves

Thoracic

Lumbar

Sacral

Liver

AUTONOMIC NERVOUS SYSTEM

6

Cerebellum

Spinalcord

HA BSLC

T

PTTh

RF

B

A

DT

CT

ECF

S

HFCTX

A7

CC

CTX

AO

OB

C

A5

A6 / locus ceruleus

NORADRENERGIC SYSTEM

Prefrontalcortex

CerebellumAnteriorcingulatecortex

Lateralseptum

Hippocampus

Caudateand putamen

Pyriformcortex

RetinaA17

B

A

A16

Thalamus

A15

A13A11

A14 A12Medianeminence

Centralnucleus(amygdala)

Entorhinalcortex

Corpuscallosum

Habenula

A10

A8

A9

StriatumLocus ceruleusLateral parabrachialnucleus

Nucleusaccumbens

Pituitary

Olfactorybulb

Spinalcord

DOPAMINERGIC SYSTEM

Externalcapsule

Cingulatebundle

Cerebral cortex

Cerebellum

B9H

Th

HF

CD

B8

B7

B6 B4 B2

B1B3

B5

Medial forebrainbundle

Serotonergic innervation

SEROTONERGIC SYSTEM

7

Cholinergic system

OBDBv

MaPo ALH

Th

VTA IPN PPT

LDT

RF

HaHi

Caudateand putamen

BM

Fornix

CHOLINERGIC SYSTEM

B

Histaminergic innervation

Cingulatecortex

Cerebral cortex

Hypothalamus

Amygdala

Septum

Thalamus

Tuberomammillarynucleus

Tuberomammillarynucleus

A

HISTAMINERGIC SYSTEM

Ca2+

PIP2

D3

(D2, D 3, D 4) (D1, D 5)

D3DAG PKC

Presynapticdopaminergicneuron

Cortical ormesolimbictargetneuron

IP3

Gi Gs

AC

+–

cAMPATP

DOPAMINERGIC SYNAPSE

8

Tyrosine

Antipsychotic

Can producepsychotic symptoms

TyrosineIncrease of synthesis(L-DOPA)

1a

2

5

Interference with vesicularstorage (reserpine,tetrabenazine)

Inhibition of reuptake(cocaine, amphetamine,benztropine)

DOPA

Dopamine

D3

D2 D2

COMT

MAO

Inhibition of synthesis(α-methyltyrosine)

1b

6Inhibition of breakdown(pargyline)

Vesicular monoaminetransporter

DopaminetransporterBlocking of DA receptors

and autoreceptors(antipsychotics:perphenazine, haloperidol)

3

4

Stimulation of release ofDA at nerve terminal(amphetamine, tyramide)

Autoreceptor

DOPAMINERGIC SYNAPSE

A Midsagittal section B Coronal section

Frontalcortex

Nucleusaccumbens(ventral striatum)

Mesolimbic andmesocorticalsystem Mesolimbic

system:? involved in thepositive symptomsof schizophrenia

Mesocortical system:? involved in thenegative symptomsof schizophrenia

Midbrain

Neocortex

Ventraltegmentalarea

Hippocampalformation

Hippocampalformation

Ventraltegmentalarea

Limbicforebrain

MESOCORTICOLIMBIC DOPAMINERGIC SYSTEM

A Pathways B Targets

Neocortex

Nucleusaccumbens(ventralstriatum)

Midbrain

Neocortex Caudate nucleusand putamen

Globuspallidus

Pons

Thalamus

Limbicforebrain

Hypothalamus

Amygdala

Striatum

Hippocampus

Tohippocampus

To spinalcord

Deepcerebellarnuclei

Rostralraphenuclei Caudal

raphenuclei

Cerebellarcortex

Olfactory and entorhinalcortices

Hypothalamus

Raphe nuclei

Medialforebrainbundle

Thalamus Cingulum

Cingulategyrus

SEROTONERGIC SYSTEM

9

A Serotonergic neurons

TryptophanInhibition of synthesis(p -chlorophenylalanine,p -propyldopacetamide)

1

2

3b

4

5

Interference withvesicular storage(reserpine,tetrabenazine) Inhibition of enzyme

that oxidizes 5-HT(iproniazid, clorgyline)

MAO inhibitors

MAO inhibitors

Tricyclics andselective serotoninreuptake inhibitors

DepressantAntidepressant

5-OH-Tryptophan

5-HT

5-HT

5-HIAA

MAO

5-HT

5-HT

5-HT receptor

Inhibition of reuptake(imipramine,amitryptyline, fluoxetine,sertraline)

Stimulation of 5-HTreceptors aspartial agonist(lysergic aciddiethylamide)

3a Stimulation ofautoreceptor agonist8-Hydroxy-diproplamino-tetraline (8-OH-DPAT)

B Noradrenergic neuronsTyrosinehydroxylase

Inhibition of synthesis(α-methyltyrosine)

1a

2

4a 5

6

Interference withvesicular storage(reserpine,tetrabenazine)

Inhibition of reuptake(desipramine)

DOPA

Dopamine

NE

COMT

NM

Deaminatedproducts

Receptor

Inhibition of synthesis(FLA 63)

1b

Inactivation inhibitor

Tricyclics

7Inhibition of enzymethat oxidizes NE(pargyline)

Inhibition of enzymethat inactivates NE(tropolone)

Stimulation of receptors(clonidine)

4b Blocking of receptors(phenoxybenzamineand phentolamine)

3 Stimulation of release ofNE at nerve terminals(amphetamine)

NE

MAO

ASCENDING AROUSAL SYSTEM

10

Appleton & Lange

Hippocampus Parabrachialnucleus

Cerebralcortex

Dorsal andmedian raphenuclei

Thalamus

Basal forebrain(cholinergic system)

Tuberomammillarynucleus

ILT

RT

Pedunculopontinenucleus

Locus ceruleus

Melanin concentratinghormone and orexinsystem

ASCENDING AROUSAL SYSTEM

A

0.2 mV

1 s

B

DESYNCHRONISED AND SYNCHRONISED EEG

EEG

Slow-wave sleep

Na+

Ca2+

Waking

Bursts Single spikes

BurstsSingle spikes

Thalamicfiringextracellular

Thalamicfiringintracellular

100 ms

0.5 s

THALAMIC NEURON ACTIVITY

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A

BCDE

A

B

C

1 min

D

E

RESPIRATORY PATTERN IN COMATOSE PATIENT

Periaqueductalgray matter

Parabrachialnucleus

Dorsal motorvagal nucleus

Nucleus of thesolitary tract

Cortex

Amygdala

Hypothalamus

Nucleus ambiguus

Ventrolateralmedulla

Heart

NUCLEUS OF THE SOLITARY TRACT COORDINATES AUTONOMIC FUNCTION

AMYGDALA AND BRAIN STEM NUCLEI COORDINATE FEAR RESPONSE