Cognitive impairment and anxiety-like behavior characterization in a rat experimental model of dopaminergic depletion induced by 6-OHDA neurotoxicity

CHAMPARINI LEANDRO; HERRERA, MACARENA; JÁVEGA COMETTO MATÍAS; BELLINI, MARIA JOSE; CALFA GASTÓN; HEREÑÚ C.B.

Congreso; SAN 2021; 2021

Parkinson´s disease is a neurodegenerative disorder that results from a progressive dopaminergic neuronal loss, characterized by multiple, motor and non-motor symptoms.. Currently its late diagnosis is based on motor deficits, but a variety of previous and coexisting non-motor symptoms result from dysfunction of interconnected systems. We aimed to determine, in an experimental rat model of neurotoxicity, the progression of working memory deficits and anxiety-like behavior and its correlation with cellular changes.Animals were stereotaxically injected with 6OHDA in dorsal lateral striatum (DLS) or with control solution, corresponding to experimental or control groups, respectively. Independent sets of rats were tested only once in a behavioral task after 2 and 3 weeks. Rats were tested in the Y-maze, elevated plus maze and locomotor activity test. Then, they were perfused and processed for IHC of different markers for neurons, astrocytes and microglia cells in the substantia nigra, DLS, dorsal hippocampus, prefrontal cortex, ventral tegmental area and basolateral amygdala.Two weeks post lesion there were no significant changes in any behavioral task. We observed working memory and anxiety-like behavior impairments in 6OHDA rats after 3 weeks of neurodegeneration, still in absence of motor alterations. These results could be associated with a partial lesion of the nigrostriatal DA system and changes in the glial cells number observed in the different brain regions. We concluded that one single bilateral infusion of 6OHDA induced non-motor alterations that preceded locomotor deficits in the employed parkinsonism animal model.