ABC	ATP-binding cassette
BBB	blood–brain barrier
BSA	bovine serum albumin
CMFDA	5-chloromethylfluorescein diacetate
CNS	central nervous system
DMEM	Dulbecco’s modified Eagles’ medium
Dpm	disintegration per minute
E	efflux ratio
ERK1/2	extracellular signal-regulated protein kinases 1 and 2
FBS	fetal bovine serum
FCS	fetal calf serum
hBLECs	human brain-like endothelial cells
HPTLC	high-performance silica gel thin-layer chromatography
LY	Lucifer yellow
GM1	II3Neu5Ac-Gg4Cer, β-Gal-(1-3)-β-GalNAc-(1-4)-[α-Neu5Ac-(2-3)]-β-Gal-(1-4)-β-Glc-Cer
MAPK	mitogen-activated protein kinase
MRPs	Multidrug resistance-associated proteins
MTT	3-(4,5,-dimethylthiazole-2yl)-2,5-diphenyltetrazolium bromide
N2a	Neuro2a cells
OligoGM1	GM1-oligosaccharide, II3Neu5Ac-Gg4, β-Gal-(1-3)-β-GalNAc-(1-4)-[α-Neu5Ac-(2-3)]-β-Gal-(1-4)-β-Glc
Papp	apparent permeability coefficient
Pe	endothelial permeability coefficient
P-gp	P-glycoprotein multidrug resistance protein 1 (MDR1)
PBS	phosphate-buffered saline
p-ERK1/2	phosphorylated ERK1/2
p-TrkA	phosphorylated TrkA
R123	Rhodamine 123
RH buffer	Hepes-buffer Ringer’s solution
RRID	research resource identifier
TJ	tight junctions
TrkA	neurotrophin tyrosin kinase receptor
Tyr490	tyrosine 490