1-M-d-T	1-Methyl-D-tryptophan
3-HANA	3-hydroxyanthranilic acid
3-HAOO	3-hydroxyanthranilic oxidase
3-HK-3	hydroxykinurenine
AA	anthranilic acid
AhR	aryl hydrocarbon receptor
AMPA	α-amino-2,3-dihydro-5-methyl-3-oxo-isoxazolpropionic acid
APCs	antigen-presenting cells
BBB	blood–brain barrier
BH4	tetrahydrobiopterin
C1q	complement component 1q
CCI	chronic constriction injury
CD40	cluster of differentiation 40
CNS	central nervous system
DCs	dendritic cells
DRG	dorsal root ganglia
GFAP	glial fibrillary acidic protein
GPR35	G-protein coupled receptor 35
HCN channels	hyperpolarization-activated cyclic nucleotide–gated channels
HIV	human immunodeficiency virus
IASP	The International Association for the Study of Pain
IBA-1	allograft inflammatory factor 1
IDO	indoleamine 2,3-dioxygenase
IFN-1β	interferon beta -1
IFN-6	interferon-6
IFN-gamma	interferon gamma
IL-1	interleukin 1
IL-10	interleukin-10
IL-1β	interleukin 1 beta
IL-4	interleukin-4
IL-6	interleukin-6
KAR	kainic acid receptor
KATs	kynurenine aminotransferases
KM	Michaelis constant
KMO	kynurenine-3-monooxygenase
KP	kynurenine pathway
KYNA	kynureinc acid
KYNU	kynureninase
L-KYN	L-kynurenine
L-KYN	L-kynurenine
MAO-B	B monoamine oxidase
NAD	nicotinamide adenine dinucleotide
NMDA	N-methyl-D-aspartate
NOS2	Nitric oxide synthase 2
QUIN	quinolinic acid
ROS	reactive oxygen species
SC	spinal cord
SNI	sciatic nerve injury
SNL	spinal nerve ligation
SNRIs	serotonin-noradrenaline reuptake inhibitors
SOD	superoxide dismutase
TCAs	tricyclic antidepressants
TDO	tryptophan 2,3-dioxygenase
TNF-α	tumor necrosis alpha
TRP	tryptophan
UPF648	(1S,2S)-2-(3,4-Dichlorobenzoyl)cyclopropanecarboxylic acid
XA	xanturenic acid