Prodromal timeline of a Parkinson’s disease model: anxiety-like behavior precedes cognitive and motor impairment.

CHAMPARINI LEANDRO; HERRERA MACARENA; COMETTO MATIAS; NARANJO VITERI ARACELY; CRESPO ROSANA; CALFA GASTON; HEREÑU CLAUDIA

Congreso; Reunión conjunta SAIC, SAI, SAFICI y FAIC.; 2022

Parkinson’s disease results from a progressive dopaminergic neuronalloss, characterized by multiple motor and non-motor symptoms.Currently, its diagnosis is based on motor deficits, but thereis also a variety of previous and coexisting non-motor symptomsthat result from dysfunction of interconnected systems. We aimedto determine, in a rat model of neurotoxicity, the progression of deficitson cognitive tasks and anxiety-like behavior before the onset ofmotor impairment. Animals, at day 0, were injected with 6-OHDA orwith vehicle solution into the dorsolateral striatum (experimental orcontrol groups, respectively). Independent groups of rats were testedonly once in a behavioral task after 1, 2 and 3 weeks post lesion(Contextual fear conditioning, Y-maze, elevated plus maze, lightdarkbox test and locomotor activity test). We observed anxiety-likebehavior 2 and 3 weeks post lesion. We observed working memoryimpairment in 6-OHDA rats after 3 weeks of neurodegeneration,without motor alterations. These results could be associated with apartial lesion of the nigrostriatal DA system as we found a decreasein tyrosine hydroxylase immunoreactivity in substantia nigra, ventraltegmental area, and striatum. We concluded that a single bilateralinfusion of 6OHDA induced anxiety-like behavior before cognitivealterations that preceded locomotor deficits in the employed dopamine-depleted animal model.