Imbalanced Dopaminergic Transmission Mediated by Serotonergic Neurons in L-DOPA-Induced Dyskinesia

Table 2

Changes in biochemical, morphological, and molecular 5-HT indexes in dyskinetic (LID) versus nondyskinetic (LND) animals: correlation with dyskinesias (R).

Animal model	L-DOPA treatment	Biochemical 5-HT indexes	LID versus LND (R)	Reference
6-OHDA rats	6 mg/kg/d ip 14 d	tiss 5-HT: STR and CX	LID > LND; R = 0.73 in CX	[84]
6-OHDA rats	12 mg/kg/d sc 5 d	tiss 5-HT (5,7-DHT): STR	R = 0.713	[85]
6-OHDA rats	6 mg/kg/d sc 14 d	ext and tiss 5-HT and 5-HIAA: STR and SNr	LID > LND in STR	[48]
6-OHDA rats	6 mg/kg/d ip 21 d	tiss 5-HT: STR	LID > LND; R = −0.655	[72]
Animal model	L-DOPA treatment	Morphological 5-HT indexes	LID versus LND (R)	Reference
6-OHDA rats	5 mg/kg/d ip 14 d	SERT immunoreactivity: STR	LID > LND	[73]
6-OHDA rats	6 mg/kg/d ip 21 d	5-HT immunoreactivity and AADC levels: STR	LID > LND	[74]
6-OHDA rats	6 and 50 mg/kg/d ip 14–21 d	SERT-binding density: STR and CX	LID > LND, R = 0.796 in STR	[55]
MPTP monkeys	Modopar (4 : 1) 15–20 mg/kg po 6–8 m	SERT-binding density: PUT and GP	LID > LND in PUT	[55]
Animal model	L-DOPA treatment	Molecular 5-HT indexes	LID versus LND (R)	Reference
MPTP monkeys	Prolopa 100/25 mg/kg po 1 m	5-HT2AR-binding: STR and PFC	LID > LND in DM Caud and anterior cingulate gyrus	[78]

6-OHDA: 6-hydroxydopamine; MPTP: 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine; ip: intraperitoneal; sc: subcutaneous; po: oral; d: day; m: month; tiss: tissue; ext: extracellular; 5-HT: serotonin; 5-HIAA: 5-hydroxyindolacetic acid; 5,7-DHT: 5,7-dihydroxytryptamine; AADC: amino acid decarboxylase; SERT: serotonergic transporter; 5-HT_2AR: serotonin 2A receptor; STR: striatum; CX: cortex; SNr: substantia nigra pars reticulata; PUT: putamen; PFC: prefrontal cortex; GP: globus pallidus; DM Caud: dorsomedial caudate nucleus; LID: L-DOPA-treated dyskinetic animals; LND: L-DOPA-treated nondyskinetic animals; R: correlation.