DR. RUSHDAN ZAKARIAHTRAINEE MEDICAL OFFICERNEUROLOGY DEPARTMENT

DMCH

BASAL NUCLEI & THEIR CONNECTIONS

Collection of masses of gray matter situated within each cerebral hemisphere.

The term ‘BASAL’ is used to denote the position of the nuclei at the base of forebrain.

What is Basal Nuclei ?

BASAL GANGLIA

BASAL NUCLEI

PRESENT NOMENCLATURE

ANATOMY

A) CAUDATE NUCLEUS

B) LENTIFORM NUCLEUS (GLOBUS PALLIDUS & PUTAMEN)

C) CLAUSTRUM

D) AMYGDALOID NUCLEUS

Basal Nuclei consists of

A) Sub thalamic nucleus

B) Substantia Nigra (Mid brain)

Functionally Related Nuclei

DEVELOPMENT: TELENCEPHALONMEDIAL GANGLIONIC EMINENCE: Projection neurons for Caudate,

Putamen

LATERAL GANGLIONIC EMINENCE: Projection

neurons for Globus Pallidus & most striated

inter neurons

BASAL NUCLEI ANATOMY

Lies lateral to the lateral ventricles, C shaped, encloses thalamus & internal capsule

o STRUCTURE: Head, Body and Tail

CAUDATE NUCLEUS

CAUDATE NUCLEUS:

Head: Lies into the space of Anterior horn

Body: Forms floor of central part

Tail: Forms roof of inferior horn, joins amygdaloid body

Relationship with Lateral Ventricle

LENTIFORM NUCLEUS:

Globus Pallidus:

Situated medially, got 2 segments,

GPi & GPe

Putamen: Situated laterally

Forms lateral boundary of internal capsule

LENTIFORM NUCLEUS

CLAUSTRUM

AMYGDALOID NUCLEUS

Nuclear mass in temporal lobe,

continuous with tail of caudate

nucleus

Function is closely related to limbic

system or hypothalamus

SUBSTANTIA NIGRA

MEDIUM SPINY NEURON

90% of the neurons

Primary Projection Neurons

Inhibitory (GABAergic)

Very little spontaneous activity

BASAL NUCLEI ANATOMY

BASAL NUCLEI ANATOMY

BLOOD SUPPLY

BLOOD SUPPLY

INPUT & OUTPUTMODULATION

Cerebral Cortex

Substantia

Nigra (Pc)

Thalamus

INPUT

Input modulation

The caudate & putamen receive input from the cortex, and …

… from the thalamus

OUTPUT

Substantia

Nigra (Pr) to

Thalamus

GPi to Thalamus

CONNECTIONS &

PATHWAYS

CONNECTIONS (Afferent and Efferent)

INTRINSIC PATHWAYSDirect Pathway: Striatum > GPi, SNr > Thalamus

Indirect Pathway: Striatum > GPe > STN > GPi, SNr > Thalamus

Net Effects:

Direct pathway: Thalamus (+): Facilitation of movement

Indirect pathway: Thalamus (-):Inhibition of movement

COMPARISON

FUNCTION

Cognition control

Movement Coordination

Voluntary movement control

THANK YOU !