WHO	World Health Organization
PD	Parkinson’s disease
CNS	central nervous system
BBB	blood–brain barrier
AD	Alzheimer’s disease
Aβ	β-amyloid
GSK-3β	glycogen synthase kinase-3β
CDK5	cyclin-dependent kinase 5
TREM2	Triggering Receptor Expressed on Myeloid cells 2
NLRP3	NOD-, LRR-, and pyrin domain-containing protein 3
SNCA	synuclein alpha gene
PINK1	PTEN-induced kinase 1
GBA1	Glucocerebrosidase 1
ASOs	antisense oligonucleotides
GDNF	glial cell line-derived neurotrophic factor
ALS	amyotrophic lateral sclerosis
C9orf72	chromosome 9 open reading frame 72
SOD1	superoxide dismutase 1
TDP-43	TAR DNA-binding protein 43
HD	Huntington’s disease
HTT	huntingtin
AAV	adeno-associated virus
P-gp	P-glycoprotein
BCRP	breast cancer resistance protein
TfR	transferrin receptor
IR	insulin receptor
LRP1	low-density lipoprotein receptor-related protein 1
CSF	cerebrospinal fluid
clogP	calculated logP
PSA	polar surface area
MPO	multiparameter optimization
PET	positron emission tomography
LAT1	L-type amino acid transporter 1
LNPs	lipid nanoparticles
pKa	acid dissociation constant
GMP	Good Manufacturing Practices
PLGA-PEG	poly(lactic-co-glycolic acid)–polyethylene glycol
RVG29	rabies virus glycoprotein 29
MSNs	mesoporous silica nanoparticles
BDNF	brain-derived neurotrophic factor
iPSC	induced pluripotent stem cell
Fe3O4	iron(II,III) oxide
MSC	mesenchymal stem cell
ROS	reactive oxygen species
RGDyK	arginylglycylaspartic acid-tyrosine-lysine
tMCAO	transient middle cerebral artery occlusion
MMP-9	matrix metalloproteinase-9
Rx	diagnostic and therapeutic
MRI	magnetic resonance imaging
FcRn	neonatal Fc receptor
AUC	area-under-the-curve
PrP	prion protein
siRNA	small interfering RNA
CED	Convection-Enhanced Delivery
VEE	Venezuelan equine encephalitis
saRNA	self-amplifying RNA
circRNA	circular RNA
SpCas9-HF1	Streptococcus pyogenes Cas9-High Fidelity 1
ABE8e	adenine base editor 8e
dCas9-KRAB-MeCP2	deactivated Cas9 fused to a Krüppel-associated box and methyl-CpG-binding protein 2
CAR	Chimeric Antigen Receptor
IL-10	Interleukin-10
TNF-α	tumor necrosis factor-alpha
IL-1β	Interleukin-1 beta
CD14	Cluster of Differentiation 14
NSC	neural stem cell
TK/GCV	thymidine kinase/ganciclovir
FUS	focused ultrasound
AADC	aromatic L-amino acid decarboxylase
UPDRS	Unified Parkinson’s Disease Rating Scale
AMF	alternating magnetic field
TRPV1	transient receptor potential vanilloid 1
PCI	photochemical internalization
FDA	U.S. Food and Drug Administration
ARIA	amyloid-related imaging abnormalities
PK–PD	pharmacokinetic–pharmacodynamic
CARPA	complement activation-related pseudo-allergy
pHEA	poly(2-hydroxyethyl aspartamide)
CCM	Chemistry, Controls, and Manufacturing
PDI	polydispersity index
vg	vector genomes
CEAs	cost-effectiveness analyses
ICER	incremental cost-effectiveness ratio
QALY	quality-adjusted life-year
EMA	European Medicines Agency
ATMP	Advanced Therapy Medicinal Product
AI	artificial intelligence