Dr Kifayat khan Mphil Anotomy KMU peshawer

1. TTHHEE BBAASSAALL
GGAANNGGLLIIAA
Dr Kifayat khan
Mphil Anatomy
KMU Peshawer

2. Discussion on basal ganglia
1)NeuroAnatomy
2) NeuroPhysiology
3)NeuroPathology

3. Basal ganglia
Basal ganglia is collection of gray matter which
perform two functions:
1. Initiate movements
• The cerebellum governs the movement itself, but the initiation of the
motor pattern in context is governed by the basal ganglia.
2.Gross control over movements
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4. 1)Anatomy
A. BG components
B. Anatomical connectivity
A) B.G components
The basal ganglia is a collection of gray
matter in the cerebrum
There are two classifications of basal ganglia
a) Transitional classification
which include
» Caudate
» Lentiform
» Amygdaliod body
» Claustrum

7. Anatomy of BG(cont…)
b) clinically its
– Caudate
– Lentiform
• Putamen
• Globus pallidus
– Subthalamus
– Substentia nigra
(caudate nucleus +putamen=straitum)

9. Connections of BG
B. Anatomical connectivity
•Main connection is between cerebral cortex,
thalamus and basal ganglia along with
associated nuclei like
•Striatum
•Substantia nigra
•Sub thalamic nucleus

10. 2.Neuro physiology
Basal ganglia has two pathways
A. Direct pathway ( excitatory )
B. Indirect pathway ( inhibitory )
A. Direct pathway
• It consists of the following types of fibers
– Cortico straital fibers ( release glutamate)
– Straito glubus internus fibers ( release GABA )
– Paladothalmic fibers ( release GABA )
– Thalmocortical fibers ( release GABA )

11. Direct pathway
Cerebral cortex
glutamate
ABAG
gaba
Lentiform nucleus
thalamus
A

12. A.Direct pathway
• When some thinking process starts at A in
Cerebral cortex it will stimulate cortico straital
fibers which will release glutamate
• This will cause stimulation of straito
Globus internus fibers which will release
GABA on palido-Thalamic fibers causing its
Inhibation
• Inhibation of palido-Thalamic fibers will
Cause decrease release of GABA on thalmo cortical
Fibers so that its firing rate is increased. Motor cortex will b
stimulated and desired action will b performed.
• So direct pathway is stimulatory

13. B. Indirect pathway
• It consists of the following fibers
– Cortico striatal fibers ( glutamate )
– Straito globus extrnus ( GABA )
– Pallido sub thalamic ( GABA)
– Sub thalamu globus internus (glutamate)
– Pallido thalamic ( GABA )
– Thalamo cortical ( glutamate )

14. Indirect pathway
Cerebral cortex
GPe
Sub thalamus
Lentiform nucleus
A

15. B. Indrect pathway
• When some thinking process starts at A in it will
stimulate corticostraital fibers which will release
Glutamate.
• This will cause stimulation of straito
Globus externus fibers which will release
GABA on palido-subThalamic fibers causing
its Inhibation and decrease relaese of GABA
• Inhibation of palido-subThalamic fibers will
Cause increase release of glutamate by subthalmo globus internus on
Palido thalmic fibers so that its firing rate is increased and in turn
Palido thalmic fibers will increase relaese of GABA on thalamo cortical fibers
Motor cortex will be inhibited and desired action will b stopped.
• So direct pathway is inhibitory.

16. Role of substantia nigra
Cerebral cortex
GPe GPi
Substentia nigra
subthalamus
d2
d1

17. Role of S.N
• Neuro transmitter for
this pathway is Dopamine
• Dopamine excites the direct pathway
through D1 receptor and inhibits the
Indirect pathway through D2 receptor
• Acetyl choline drives (excites) indirect
Pathway decreasing cortical excitation.

18. C. Neuropathology
Cerebral cortex
GPe GPi
Huntington
disease
Wilson
disease
Substentia nigra
subthalamus
d2
d1
Parkinson’s
disease
hemibalism

19. DDIISSEEAASSEESS OOFF TTHHEE BBAASSAALL
GGAANNGGLLIIAA
• 1) Parkinson disease
– Hypokinesia
– Rigidity ( lead pipe)
– Tremors ( resting )
• Treatment: when we give l-dopa it will cause excitation of direct pathway and
inhibition of indirect pathway so causing promotion of movements
• 2) wilson disease
• Accumulation of copper in liver, basal ganglia and eye
• Treatment is penicillamine

20. Diseases of B.G
3) Huntington disease
• Degeneration of neurons in neostriatum
– Chorea ( its multiple rapid random movements)
– Athetosis ( slow writhing movements )
• Treatment antipsychotic , benzodiazepines
4) Hemibalism
• Hemorrhagic destruction of subthalamic nucleaus
– Wild flinging movements of limbs