Functions of Diencephalon & Subcortical Ganglia

1. INTEGRATIVE FUNCTIONSINTEGRATIVE FUNCTIONS
OF DIENCEPHALON &OF DIENCEPHALON &
SUBCORTICAL GANGLIASUBCORTICAL GANGLIA

2. THALAMUSTHALAMUS
Consists of about 40 nuclei which areConsists of about 40 nuclei which are
divided functionally into groupsdivided functionally into groups

3. I.I. SPECIFIC OR RELAYSPECIFIC OR RELAY
NUCLEINUCLEI
Lateral geniculate body (LGB) –Lateral geniculate body (LGB) –
visual modalityvisual modality
Medial geniculate body (MGB)Medial geniculate body (MGB)––
auditory modalityauditory modality
Ventro-basilar complex (VP) –Ventro-basilar complex (VP) –
somato-sensory modalitysomato-sensory modality

4. Ventro-posterio-lateral nucleusVentro-posterio-lateral nucleus
( VPL( VPL ))
Lemniscus medialis &
Spino-thalamic tracts
Skin & proprio-receptors,
Including pain receptors
n.vagus
interoreceptors

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6. Ventro-posterio-medial nucleusVentro-posterio-medial nucleus
( VPM( VPM ))
Vestibulo-receptors
Face receptors
Lemniscus medialis
Gustatory receptors
Vestibular
pathways
n. trigeminus

7. Specific nucleiSpecific nuclei
Function – get sensory information fromFunction – get sensory information from
specific pathways & send it to specificspecific pathways & send it to specific
sensory zones of cortex.sensory zones of cortex.
Topical organization – each neuron isTopical organization – each neuron is
connected with specific receptive fieldconnected with specific receptive field

8. Lateral inhibition in thalamus helpsLateral inhibition in thalamus helps
to cut off aberration & defineto cut off aberration & define
important sensory signal –important sensory signal –
information
Goldgi neurons
Afferent
neurons

9. IIII MOTOR NUCLEUSMOTOR NUCLEUS
ventrolateral (VL)ventrolateral (VL)
Is included in the system of movemntIs included in the system of movemnt
regulation.regulation.
Gets impulses from cerebellum & basalGets impulses from cerebellum & basal
ganglia.ganglia.
Sends information to motor cortex (pre-Sends information to motor cortex (pre-
central gyrus).central gyrus).

10. Th
Cortex
Hypothalamus
Cerebellum &
Basal ganglia
Information analysis
Regulation of visceral
functions
Regulation of movements

11. IIIIII ASSOCIATIVE NUCLEIASSOCIATIVE NUCLEI
Pulvinar -Pulvinar - is connected with temporal &is connected with temporal &
parietal associative cortexparietal associative cortex
Posterio-lateral nucleus (LP) –Posterio-lateral nucleus (LP) – isis
connected with temporal cortexconnected with temporal cortex
Medio-dorsal nucleus (MP) –Medio-dorsal nucleus (MP) – is connectedis connected
with frontal cortexwith frontal cortex
Anterior nucleus –Anterior nucleus – is connected with limbicis connected with limbic
cortexcortex

12. All associative nuclei are gettingAll associative nuclei are getting
poly-modal signals from:poly-modal signals from:
Specific relay nucleiSpecific relay nuclei
Specific afferent pathwaysSpecific afferent pathways
They are included into the associativeThey are included into the associative
systems of the brain & take part in thesystems of the brain & take part in the
integrative processes forming behaviourintegrative processes forming behaviour
and memory.and memory.

13. IVIV NON-SPRCIFIC NUCLEINON-SPRCIFIC NUCLEI
INTRALAMINAR & MEDIUM GROUP OFINTRALAMINAR & MEDIUM GROUP OF
NUCLEINUCLEI , they are continuation of reticular, they are continuation of reticular
formation of the brain stem and are poly-formation of the brain stem and are poly-
modal because they get information frommodal because they get information from ::
RF of brain stemRF of brain stem
Specific afferent pathwaysSpecific afferent pathways
SpecificSpecific thalamus nucleithalamus nuclei
Send impulses diffusively to all the cortexSend impulses diffusively to all the cortex
zoneszones

14. THALAMUS IS THE HIGHESTTHALAMUS IS THE HIGHEST
CENTER OF PAINCENTER OF PAIN

15. FUNCTIONALFUNCTIONAL
CLASSIFICATION OFCLASSIFICATION OF
THALAMUS NUCLEITHALAMUS NUCLEI

16. Sensor zones
of cortex
Associative zones
of cortex
Motor zones
of cortex
Sensor information
from receptors
Sensor specific
nuclei
Non-specific nuclei
Associative
nuclei
Cerebellum &
basal ganglia
Motor
nuclei

17. HYPOTHALAMUSHYPOTHALAMUS

18. ANATOMICAL STRUCTURES:ANATOMICAL STRUCTURES:
TUBER CINEREUMTUBER CINEREUM
HYPOPHYSISHYPOPHYSIS
CORPORA MAMMILLARIACORPORA MAMMILLARIA

19. ANATOMICAL PECULIARITIESANATOMICAL PECULIARITIES
GROUS OF NUCLEA ARE NOTGROUS OF NUCLEA ARE NOT
STRICTLY LOCALISEDSTRICTLY LOCALISED
NO BLOOD-BRAIN BARRIERNO BLOOD-BRAIN BARRIER
MULTIPLY CONNECTIONS WITHMULTIPLY CONNECTIONS WITH
OTHER СNS STRUCTURESOTHER СNS STRUCTURES

20. Medial
hypothalamus
Lateral
hypothalamus
Thalamus – anterior nuclei
Cortex
adenohypophysis neurohypophysis
liquor blood
RF of
hindbrain
RF of midbrain
Globus
pallidus
Limbic system

21. Modern views onModern views on
hypothalamic functionshypothalamic functions

22. GETTING INFORMATIONGETTING INFORMATION
ABOUT EXTERNAL ENVIRONMENTABOUT EXTERNAL ENVIRONMENT – via– via
nervous connections from thalamus, RF, cortexnervous connections from thalamus, RF, cortex
ABOUT INTERNAL ENVIRONMENTABOUT INTERNAL ENVIRONMENT - from- from
blood & liquor (HEB is very low)blood & liquor (HEB is very low)
Information is received by sensory neuronsInformation is received by sensory neurons
(osmoreceptors, volumoreceptors,(osmoreceptors, volumoreceptors,
glucoreceptors & others),glucoreceptors & others), which process thiswhich process this
info & form sensations.info & form sensations.

23. CENTERS OF SENSATION INCENTERS OF SENSATION IN
HYPOTHALAMUSHYPOTHALAMUS
hunger –hunger – satietysatiety
thirst –thirst – thirst satisfactionthirst satisfaction
sleep-sleep- awakenessawakeness
warmth –warmth – coldcold
aggression –aggression – calmnesscalmness

24. EFFECTOR FUNCTIONSEFFECTOR FUNCTIONS
Formation of emotions & motivation ofFormation of emotions & motivation of
behaviorbehavior due to the connections with limbicdue to the connections with limbic
systemsystem
Give rise to behavioral programsGive rise to behavioral programs
(instincts)(instincts) with the involvement of somatic &with the involvement of somatic &
vegetative NSvegetative NS
Performed by neurons effectorsPerformed by neurons effectors

25. Neurons effectors
Somatiс NS
Locomotor component
Vegetative NS
(brain stem)
Endocrine system
Vegetative component

26. Hypothalamus FUNCTIONSHypothalamus FUNCTIONS
Sensory
neurons
Effectory
neurons
External
signals
Internal
signals
Limbic system
feelings
CORTEX Emotions &
motivations
Somatic NS Vegetative NS Endocrine system
Behaviour aimed at homeostasis maintanense

27. Basal gangliaBasal ganglia
(striopallidum system(striopallidum system))
Are paired structures, grey matter located inAre paired structures, grey matter located in
the white matter of hemispheres between thethe white matter of hemispheres between the
frontal lobes & diencephalonfrontal lobes & diencephalon

28. Striopallidum integrates the functions ofStriopallidum integrates the functions of
associative &motor cortexassociative &motor cortex
Motor cortexAssociative cortex
Striopallidar
system

29. Cortex zones
SENSORY ASSOCIATIVE MOTOR
n. caudatus
putamen
Gl.Pal.
Motor nn.
of thalam.
Brain stem
Subthalamic nucleus
Subst. Nigrum
dopamine
dopamine

30. As it is clear from the scheme the afferentAs it is clear from the scheme the afferent
input gets into striatum, аnd the efferentinput gets into striatum, аnd the efferent
influences are performed by globusinfluences are performed by globus
pallidum alone.pallidum alone.
Due to the connections with motor cortexDue to the connections with motor cortex
via thalamusvia thalamus BG take part in realization ofBG take part in realization of
movement programme.movement programme.

31. Mediators:Mediators:
Substantia nigrum neurons secreteSubstantia nigrum neurons secrete
dopaminedopamine
N.caudatum & claustrum neurons – areN.caudatum & claustrum neurons – are
connected with pallidus, they secreteconnected with pallidus, they secrete
GABAGABA
Cortex neurons send impulses to striatumCortex neurons send impulses to striatum
& secrete& secrete acetylcholineacetylcholine

33. Striopallidum effects:Striopallidum effects:
Activates motor neurons ofActivates motor neurons of flexorsflexors viavia
pyramidal tractspyramidal tracts
Multiply influences on flexors & extensors toneMultiply influences on flexors & extensors tone
via motor neurons of brain stemvia motor neurons of brain stem
Inhibits stretching reflexes влияя на альфа иInhibits stretching reflexes влияя на альфа и
гамма мотонейроны вместе с чернойгамма мотонейроны вместе с черной
субстанцией через двигательные ядрасубстанцией через двигательные ядра
ствола мозгаствола мозга
So striopallidum facilitates the performance ofSo striopallidum facilitates the performance of
such complex movement programs as writing,such complex movement programs as writing,
musical instruments playing,musical instruments playing,

34. Striopallidum effects:Striopallidum effects:
Control of some involuntarily movementsControl of some involuntarily movements
in emotional statesin emotional states
Together with cerebellum helps to keepTogether with cerebellum helps to keep
movement programs & information aboutmovement programs & information about
learnt movementslearnt movements
Regulate the glossary muscles activity toRegulate the glossary muscles activity to
modulate voice & speechmodulate voice & speech

35. STRIOPALLIDAR SYSTEMSTRIOPALLIDAR SYSTEM
FUNCTIONSFUNCTIONS
1.1. Regulation of acurate hand movementsRegulation of acurate hand movements
2.2. Keeping movement programsKeeping movement programs
3.3. Regulation of vegetative functionsRegulation of vegetative functions
4.4. Switches on programs of instinct behaviourSwitches on programs of instinct behaviour
(orientation, defense reflexes).(orientation, defense reflexes).

36. Pathological states at strio-pallidumPathological states at strio-pallidum
affectionaffection
When Substantia Nigrum connections withWhen Substantia Nigrum connections with
subcortical ganglia are affected or at the lacksubcortical ganglia are affected or at the lack
of dopamineof dopamine tremor at resttremor at rest developsdevelops, as well, as well
as other symptoms of Parkinsonismas other symptoms of Parkinsonism
When striatum is affected tremor developsWhen striatum is affected tremor develops
both at rest & during movement (chorea), plusboth at rest & during movement (chorea), plus
hyperkinesiahyperkinesia

37. Pathological signs at strio-Pathological signs at strio-
pallidum affectionpallidum affection
When globus pallidum is affected hypokinesiaWhen globus pallidum is affected hypokinesia
developsdevelops
In rheumatic chorea both hypo -&In rheumatic chorea both hypo -&
hyperkinesias develop, mimic muscles arehyperkinesias develop, mimic muscles are
affected, handwriting is changedaffected, handwriting is changed

38. PARKINSON DISEASEPARKINSON DISEASE
CLINICAL SIGNSCLINICAL SIGNS

41. Stereotaxis: 1 -
electrode, 2 –
ear fixators, 3 –
upper jaw
fixators

42. Frontal cross-
section of cat/s
brain with
marked
subcortical
structures мозга