Basal Ganglia tail, Substantia nigra MR sequences, MBN (nucleus basalis of Meynert), Development of brain, Brainstem (Pons / LDT / Locus coeruleus / Medulla), Borghammer 2021 BODY-FIRST vs BRAIN-FIRST PD

Substantia nigra MR sequences

Brain MRI panels A and B (T2 axial) showing SN tracing with red, blue, orange, and purple regions.

Side panels:

• 2D GRASE — × 2mm, 0 gap
• C — 3D FFE — 0.4 × 0.4 × 2mm

Color Legend:

• Cerebral peduncles
• Substantia Nigra (pars compacta)
• Substantia Nigra (pars reticulata)
• Mammillary Body
• Red nucleus, poorly vascularized part
• Red nucleus, densely vascularized part
• Ventral Tegmental Area

Footnote: P = Posterior; PCA = Posterior Cerebral Artery

Caudate-nucleus / putamen / globus-pallidus diagram legend: a caudate nucleus; b putamen; c globus pallidus; d thalamus; e lentiform nucleus = b + c; f striatum = a + b

MBN (nucleus basalis of Meynert)

• diffuse collection of large cholinergic neurons in the basal forebrain.[2], a group of neurons located mainly in the substantia innominata of the basal forebrain.[1]
• Most neurons of the nucleus basalis are rich in the neurotransmitter acetylcholine, and they have widespread projections to the neocortex and other brain structures.[2]

MBN cartoon labels: Frontal cortex, Septum pellucidum, Nucleus basalis of Meynert, Amygdala, Hippocampus, Entorhinal cortex.

Development of brain (brain vesicles)

primary vesicle	secondary vesicle	derivatives	sub-derivatives
forebrain	diencephalon	Thalamus
		hypothalamus
		Epithalamus
		subthalamus
	telencephalon	cerebrum	Cerebral cortex
			White matter
			Basal ganglia
Midbrain (mesencephalon)
Hindbrain (rhombencephalon)	Pons
	Medulla
	cerebellum

Brainstem

good resource: http://what-when-how.com/neuroscience/brainstem-iii-the-midbrain-organization-of-the-central-nervous-system-part-1/

Brainstem anatomy figure (Pons-centred): Pons, which links the cerebellum with the midbrain, diencephalon, cerebrum, medulla oblongata, and spinal cord.

Diagram labels: Midbrain, Pons, Medulla oblongata, Spinal cord; Tracts (Ascending tracts / Descending tracts), Transverse fibers, Olivary nucleus; Respiratory Centers (Pneumotaxic center, Apneustic center); Cerebellum; Fourth ventricle; Reticular formation.

Brainstem	Midbrain	SN	Connection: output	Function
Pons	Raphe nuclei : serotonergic	tegmentum	Laterodorsal tegmental nucleus: The laterodorsal tegmental nucleus (or lateroposterior tegmental nucleus) is a nucleus situated in the brainstem, spanning the midbrain tegmentum and the pontine tegmentum. Its location is one-third of the way from the pedunculopontine nucleus to the thalamus, inferior to the pineal gland.	The laterodorsal tegmental nucleus (LDT) sends cholinergic (acetylcholine) projections to many subcortical and cortical structures, including the thalamus, hypothalamus, substantia nigra (dopamine neurons), ventral tegmental area (dopamine neurons), cortex (with bidirectional connections with the prefrontal cortex).
		The laterodorsal tegmental nucleus may be involved in modulating sustained attention or in mediating alerting responses, and also in the generation of REM sleep (along with the pedunculopontine nucleus).
Pons	Locus coeruleus: noradrenergic	-part of the reticular activating system. -the principal site for brain synthesis of norepinephrine -it is composed of mostly medium-size neurons. -Melanin granules inside the neurons of the LC contribute to its blue colour. -In adult humans (19-78) the locus coeruleus has 22,000 to 51,000 total pigmented neurons that range in size between 31,000 and 60,000 μm3.[3]	The projections from the locus coeruleus consist of neurons that utilize norepinephrine as their primary neurotransmitter.[4][5] These projections include the following connections:[4][5] LC → Amygdala and Hippocampus LC → Brain stem and Spinal cord LC → Cerebellum LC → Cerebral cortex LC → Hypothalamus LC → Tectum LC → Thalamus LC → Ventral tegmental area	It is related to many functions via its widespread projections. The LC-NA system modulates cortical, subcortical, cerebellar, brainstem, and spinal cord circuits. Some of the most important functions influenced by this system are:[6][7] Arousal and sleep-wake cycle Attention[8] and memory Behavioral and cognitive flexibility,[9] creativity,[10] behavioral inhibition and stress (psychological) Cognitive control Decision making and utility maximization[11] Emotions Neuroplasticity Posture and balance The locus coeruleus is a part of the reticular activating system, and is almost completely inactivated in rapid eye movement sleep.[12]
Medulla oblongata
Olivary body

(Borghammer, 2021 #1484) BODY-FIRST PD vs BRAIN-FIRST PD

BODY-FIRST PD	BRAIN-FIRST PD
autonomic symptoms RBD autonomic prodromal phase	Fewer autonomic symptoms No prodromal RBD Less damage to autonomic systems in prodromal phase Slower progression
Motor symptoms more symmetric Dopamine transporter loss more symmetric	SN, LC, DMV, amygdala (numbered 1-4 progression) heart, vagus, intestine route Motor symptoms more asymmetric Dopamine transporter loss more asymmetric

Uncertain Spans

location	transcription	uncertainty
Borghammer panel / numbered sequence	numbered nodes 1-5 (BODY-FIRST) and 1-4 (BRAIN-FIRST)	the numbered SN / LC / DMV / amygdala progression labels are partially clipped at the bottom edge; preserved as text-only abstractions.
Borghammer panel / asymmetric phrases	Motor symptoms more asymmetric, Dopamine transporter loss more asymmetric	reads as written; the BRAIN-FIRST asymmetric labels are partially clipped at the bottom edge.