BASAL NUCLEI GANGLIA Dr A Gandotra HOD Professor
BASAL NUCLEI (GANGLIA) Dr. A. Gandotra HOD & Professor Department of Anatomy S. B. K. S. M. I. & R. C.
Ø Sub cortical grey masses lateral to thalamus They include: 1. Caudate nucleus 2. Putamen LENTIFORM NUCLEUS 3. Globus pallidus 4. Claustrum 5. Amygdaloid complex 6. Sub thalamic nucleus 7. Substantia nigra
CAUDATE NUCLEUS CORPUS STRIATUM INTERNAL CAPSULE LENTIFORM NUCLEUS DORSAL CORPUS STRIATUM VENTRAL CAUDATE NUCLEUS LENTIFORM NUCLEUS
DORSAL DIVISION Ø Inferior part of the head is continuous with most inferior part of putamen together called Dorsal Striatum 1. Caudate nucleus: Arcuate mass, Head, Body, Tail. Head: In front of I/V foramen : Floor anterior horn Body: Floor body of lateral ventricle
Tail: Roof of inferior horn : Expanded anterior end : Contacts but remains distinct from amygdaloid comp. Medially: Separated from thalamus by sulcus terminalis : Lies stria terminalis : Thalamostriate vein in antero-superior part only Laterally: Anterior limb internal limb Superiorly: Corpus callosum separated by fronto-occipital Fasc.
Lentiform nucleus: : Lies deep to insular cortex : Claustrum is co-extensive with insular cortex : It splits sub cortical insular white matter into a) Extreme and External capsule : Tetrahedron, base – laterally forwards apex – medially backwards : Medially: Internal capsule
: Has two parts – a) Laterally: - Putamen, more cell population b) Medially: - Globus Pallidus (Dorsal pallidum) - Separated by external medullary lamina - Globus pallidus has two parts: : medial and lateral separated by internal medullary lamina. - Inferiorly globus pallidus is grooved by anterior commissure.
VENTRAL DIVISION : Smaller 1. Ventral striatum: Nuc accumbens, olfactory tubercle : Lies in front of anterior commissure : It occupies anterior ½ of anterior perforated substance. 2. Ventral pallidum: lies posterior to ventral striatum : Below the crossing of anterior commissure : It occupies posterior ½ of anterior perforated substance.
BLOOD SUPPLY Lentiform nucleus - Antero-superior part : Lenticular striate artery : Anterior cerebral artery : Middle cerebral artery - Postero-inferior part : Thalamostriate branch of posterior cerebral artery Caudate nucleus: Anterior choroidal artery : Posterior choroidal artery
SUB THALAMIC NUCLEUS : Magnocellular : Biconvex lens shaped : Dorsomedial to posterior limb internal capsule : Its medial part overlies rostral part of substantia nigra.
SUBSTANTIA NIGRA : Largest cell mass of diencephalon : It closely approaches globus pallidus : Produces dopamine
CLAUSTRUM : Thickest below and in front : Anteriorly becomes continuous with anterior perforated substance, amygdala and pre piriform cortex
AMYGDALA : Integral part of Limbic System Location: Dorsomedial part temporal lobe : Anterior to hippocampus Forms: Ventral, medial and superior walls of tip of inferior horn Deep to: Gyrus semilunaris, Ambiens and uncinate gyrus Afferent: Temporal lobe, Olfactory system Efferent: Striatum = hypothalamus = brain stem
PRINCIPAL STRIATAL CONNECTIONS NEOCORTEX 4, 6 STRIATUM THALAMUS NVA/NVL GLOBUS PALLIDUS MEDIAL
ACCESSORY STRIATAL CIRCUIT - 1 STRIATUM GLOBUS PALLIDUS MEDIAL THALAMUS. INTRALAMINAR/CENTROMEDIAN
ACCESSORY STRIATAL CIRCUIT - 2 GLOBUS PALLIDUS LATERAL SUB THALAMUS
ACCESSORY STRIATAL CIRCUIT - 3 STRIATUM SUBSTATIA NIGRA COMPACT DOPA GLOBUS PALLIDUS LATERAL SUBSTATIA NIGRA RETICULAR GABA
CLINICAL ASPECT 1. GLOBUS PALLIDUS: Spontaneous writhing movements of hand, arm, neck or face. 2. SUB THALAMUS: Sudden flailing movements of entire limb called HEMIBALLISMUS 3. PUTAMEN: Flicking movements of hand face or other parts of body called CHOREA
4. SUBSTATIA NIGRA PARS COMPACTA (DOPA): Rigidity of musculature, involuntary tremors of involved area called PARKINSON’S disease. Serious inability to initiate movement called AKINESIS 5. PUTAMEN & CAUDATE NUCLEUS: Loss of GABA neurons Flicking movements at joints and severe dementia called HUNTINGTON’S CHOREA
TITLE The functional anatomy of basal ganglia disorders AUTHOR/JOURNAL MATERIAL RESULT Roger L. Albin, This model is based Hypokinetic Anne B. Young, on a synthesis of disorders, such as John B. Penney experimental animal Parkinson's disease, Trends in and post-mortem are hypothesized to Neurosciences human anatomic result from a Volume 12, Issue 10, and neurochemical complex series of 1989, Pages 366– data. changes in the 375 activity of striatal projection neuron subpopulations resulting in an increase in basal ganglia output CONCLUSION This model suggests that the activity of subpopulations of striatal projection neurons is differentially regulated by striatal afferents and that different striatal projection neuron subpopulations may mediate different aspects of motor control.
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