Cranial nerves nuclei tail, Facial n decomposition, Nigrostriatal pathway, Wakabayashi 2006 postmortem, SNc / DA neurons, Functional subdivisions of striatum, Basal Ganglia start

Cranial nerves nuclei tail

Cranial nerve	Nuclei
Accessory nerve	Spinal accessory nucleus Nucleus ambiguus
Hypoglossal nerve	Hypoglossal nucleus

Facial n

	Two roots (branch 라는 의미 같음)	Cell body (nuclei)	Axon	Additional Cell body (='ganglion' 이것은 nucleus 저럼 cell body 의 collection 인데 brain 밖에 있음)	effector
Facial n proper (motor)		Facial nucleus (in brainstem)	SVE (branchiomotor) neurons	없음.	Muscles of facial expression etc
Nervus intermedius (sensory, parasympathetic)		superior salivatory nucleus (in brainstem)	GVE (secretomotor) parasympathetic neurons,	Geniculate ganglion	Submandibular ganglion, soft palate, nasal cavity etc

Nigrostriatal pathway

• cf) SNpc receives input from the pedunculopontine nucleus, the primary reticular formation nucleus of the ascending reticular activating system.[3] The ascending reticular activating system is a deep neural system that receives collateral innervation from afferent sensory neurons of the body along a parallel tract which ultimately activates gain setting nuclei (such as the SNpc) and limbic structures, the amygdala, and the hypothalamus in order to prime the body’s automatic functions outside of the conscious, cortical sensory pathways.
• Afferents to the substantia nigra arise mainly from the caudate nucleus and putamen of the basal ganglia. These fibers are collectively known as the striatonigral fibers. In addition, the substantia nigra receives input from the external globus pallidus, subthalamic nuclei, cerebral cortex, and other brainstem nuclei. The majority of input to the substantia nigra is inhibitory, utilizing GABA as the primary neurotransmitter.

Brain coronal section diagram labels: Cortex, Caudate (body), Thalamus, Lat, Putamen, Globus pallidus (Ext / Int / Lat), Sub. Nigra, Subthalamic Nucleus, Caudate (tail).

3D brain side-view labels: Ca Nu, Pu, NS neurons, SN.

Panel A SN immunostaining labels: VTA, SNpc, SNpr, TH⁺.

Wakabayashi 2006 postmortem (paranigral nucleus PN, medial group MG, dorsal group DG, ventrolateral part VL)

(Wakabayashi, 2006, postmortem)	In normal, pigmentation 정도	In PD, Neuronal loss 정도	LB occurrence 순서 (progression of LB is parallel to that of neuronal loss.)
paranigral nucleus (PN),	중간정도 pigmented	Intermediate degree	2
medial group (MG)	Heavily pigmented	Intermediate degree	3
dorsal group (DG)	Heavily pigmented	Less neuronal loss	4
ventrolateral part (VL).	Less pigmented	Severe neuronal loss	1

SNc

SNc		medial forebrain bundle	Dorsal striatum
dopaminergic neurons from the A9 cell group		an extremely large unmyelinated axonal arborization	caudate nucleus 와 putamen 두 곳으로 다 보냄. - there is a greater density of dopaminergic input to the dorsolateral striatum.[9] The dopaminergic axon terminals of the nigrostriatal pathway synapse onto D1 receptor containing-GABAergic MSNs in the dorsal striatum. They form synapses on the cell body and dendritic shaft regions but mostly on the necks of dendritic spines that also receive glutamatergic input to the heads of the same dendritic spines.[1] 기타: some, SNc nigrostriatal dopamine axons send axon collaterals to the pedunculopontine nucleus, the ventral palladium, subthalamic nucleus, globus pallidus, amygdala and the thalamus.[6][9][12] A small number of SNc dorsal tier dopamine neurons also project directly to the cortex, although most of the dopaminergic innervation of the cortex comes from the adjacent VTA dopamine neurons.[9] In rodents, the internal capsule is poorly developed such that the caudate and putamen are not separated but form one large entity called the caudate putamen (CPu).[15][16]
수	- 200,000 to 420,000 dopamine cells in human SNc - 8,000 to 12,000 dopamine cells in mouse SNc.[5] (human보다 30배 적네)

Substantia nigra (n = 5943) — single-nuclei transcriptomic clusters

Cell population: (Agarwal 2020) Single-nuclei transcriptomic from five (healthy 일것) human. DaNs: dopaminergic neurons, Ex: excitatory neurons, GABA: GABAergic neurons, In: inhibitory neurons, ODC: oligodendrocytes, OPC: oligo-precursor cells.

Cluster labels visible on the tSNE plot: ODC-1, ODC-2, ODC-3, Astrocytes 1, Astrocytes 2, Endothelial, Microglia, GABA, DaNs, OPC.

Cf) the pars reticulata contains mostly GABAergic neurons (?).

[중요 Functional subdivisions of striatum.]

{Kerstens, 2020 #2307} the functions within the striatum are not homogeneous and entail different functional sub-regions [31, 32]. An alternative functional subdivision, for example, is the associative, limbic, and sensorimotor subdivision (Fig. 1, [33]), which are thought to represent motor functioning, mood, and cognitive functioning, respectively. DAT PET 으로 이들 sub-region distinguish 가능?

Fig. 1 Functional subdivisions of striatum. Template as created by Tziortzi et al. (https://fsl.fmrib.ox.ac.uk/fsl/fslwiki/Atlases/striatumconn), overlaid on T1 MRI sequences. Red: sensorimotor striatum; green: associative striatum; gray: limbic striatum

Basal Ganglia

component		sub-component	afferent	note
	dorsal striatum	Caudate nucleus				Inhibitory
		putamen
	Ventral striatum	Nucleus accumbens
		Olfactory tubercle
	Globus pallidus	GPi
		GPe		[two classes of cells] - Npas1 cells: suppress motor system activation - PV cells: promote motor system activation
	Ventral pallidum
	Substantia nigra	SNpc	The mean (+/- SD) thickness values of SN were 5.1 +/- 0.89 mm	-They receive abundant afferrences from the striatum (mainly from the associative striatum) with the same very peculiar synaptology as the pallidum.	The neurons of the pars reticulata produce GABA. The neurons of the pars reticulata through the nigrothalamic bundle send axons to a particular part of the motor thalamus.
		SNpars reculata	pars reticulata contributes significantly to the total dopamine content of the substantia nigra as its weight is three times greater.	-It receives axons from the subthalamic nucleus and a dopaminergic innervation from the dopaminergic ensemble.
		Subthalamic nucleus				excitatory

dotted line - the boundaries of substantia nigra pars compacta