1. The document describes the major subcortical structures derived from the telencephalon known as the basal ganglia. 2. It details the core structures including the striatum, pallidum, and control structures such as the substantia nigra and subthalamic nucleus. 3. It provides information on the circuitry and connections between these structures, describing both excitatory and inhibitory pathways, as well as the roles of different neurotransmitters.

2. Large subcortical nuclear structures derived from
telencephalon.
1. Caudate nucleus + putamen = neostriatum
/striatum
2. Globus pallidus = paleostriatum
3. Amygdaloid complex = archistriatum
4. claustrum

3. CORE STRUCTURES
A. STRIATUM
1. caudate nucleus
2. putamen
3. ventral striatum - nucleus accumbens
B. PALLIDUM OR GLOBUS PALLIDUS
1. external segment
2. internal segment
3. ventral pallidum

4. Control structures
a. Substantia nigra
1. Pars compacta
2. Pars reticulata
3. Pars lateralis
b. Ventral tegmental area

5. c. Subthalamic nucleus
d. Thalamus and brain stem.
1. centromedian/ parafascicular complex
2. Mid brain dorsal raphe nucleus
3. Pedunculopontine tegmental nucleus

6. •Caudate Nucleus
•C shaped structure (“tail”)
•Lateral wall of lateral ventricle
•Head, body and tail

7. PUTAMEN:

8. SUBSTANTIA NIGRA

9. 1. It lies in the mid brain dorsal to cerebral
peduncles.
2. It is divided into parsreticulata and pars
compacta
3. Pars compacta: dopamine.
4. Pars reticulata fibers: Glutamine

10. SUBTHALAMIC NUCLEUS
Lies below the thalamus
Lies above the substantia
nigra
Is closely connected to
parts of the Globus
Pallidus

11. SUBTHALAMIC NUCLEUS
Receives afferents from GPe , cerebral cortex,
substantia nigra compacta and pedunculopontine
nucleus
Projects to the GPi, SNr, and striatum
Glutamatergic (excitatory)

12. Subthalamus

13. 1. Both the nucleus accumbens and the olfactory
tubercle .
2. Ventral pallidum occupies area beneath the
anterior commissure referred to as substantia
innominata.
3. The globus pallidus extends in a rostral and ventral
direction toward the surface of the brain in the
region of the olfactory tubercle.

14. 1. Broad regions of cerebral cortex
2. Centromedian – parafascicular nuclear
complex
3. Substantia nigra
4. Smaller mesencephalic nuclei
5. Portions of lateral amygdala

15. 1. CORTICO STRIATE FIBERS:
a. primary motor area: putamen.
b. Premotor area: caudate and putamen
c. Prefrontal cortex : caudate

16. 2. Thalamo striate fibers: excitatory
Intralaminar
thalamic
nuclei:
Centromedian
putamen
parafascicular
Caudate

17. PARS COMPACTA OF SUBSTANTIA NIGRA TO STRIATUM
• CAUDATE
ROSTRAL
2/3 RD
• POSTERIOR
REGIGION
PUTAMEN

18. TO STRITUM THROUGH SEROTONERGIC SYSTEM

20. 1.SUBSTANTIA NIGRA OF PARS COMPACTA ,
2.GLOBUS PALLIDUS
NEUROTRANSMITTERS : GABA, ENKEPHALIN AND
SUBSTANCE P.

21. 1.Striato pallidal : mainly to GPi,
Neurotransmitters are GABA and
substance P.

22. Both segments of pallidum, excitatory and contain
glutamate

23. 1. Ansa lenticularis
2. Lenticular fasciculus
3. Pallidotegmental
4. pallidosubthalamic

24. 1. From the GPi
2. Sweeps under the internal capsule.
3. Forel’s field H.

25. 1. Gpi to subthalamic nuclei and
zona incerta
2.Form Forel’s field of H2.
3. Penetrates the internal capsule.

26. 1. Ansa lenticularis and lenticuris fasciculus .
2.Supplies ventral anterior and ventral lateral area
3. Supply supplementary motor area
4.Premotor area

27. 3. Pallido tegmental To pedunculo pontine
nucleus
4. Pallido subthalamic, to subthalamic
nucleus

28. Pallido subthalamic fibers,
Cortico subthalamic,
Thalamosubthalmic,
Tegmento subthalamic

29. Substantia nigra,
Medial globus pallidus.

30. Basic Circuit of Basal Ganglia
Neostriatum
Gpi/SNpr
Cerebral Cortex
VA/VL thalamus
+
+
Gpe
Subth
+

31. Blood supply of basal ganglia
Perforating branches of circle of Willis
Lenticulostriate arteries from MCA
Anterior choroidal artery
Perforating branches of circle of Willis
Lenticulostriate arteries from MCA
Anterior choroidal artery

32. Blood supply of basal ganglia

33. Blood supply of basal ganglia

34. Blood supply of basal ganglia

35. ZONA INCERTA

36. Cytoarchitecture
 Main neurotransmitter in basal
ganglia is GABA
 95% of neurons in neostriatum are
medium spiny neurons (rodent)
 Contain GABA
 Principal neurons: project to
globus pallidus and SNpr
 Subpopulations are
distinguished by peptides,
neurotransmitter receptors and
connections
 Receive bulk of afferent input
 Several populations of interneurons
 aspiny
 ACh, GABA/parvalbumin,
GABA/calretinin;
GABA/NPY/NADPH/Somatosta
tin

37. STRIATAL COMPARTMENTS
 STRIASOMES (OR
PATCHES).
 EXTRASTRIOSOMAL
“MATRIX”.

38. STRIOSOMES :
1. High levels of opiate receptors,
2. Substance P
3. Neurotensin
4. Tyrosine hydroxylase.

39. Acetylcholinesterase (AchE) activity
Somatostatin activity
Neurotensin