The Intranigral Infusion of Human-Alpha Synuclein Oligomers Induces a Cognitive Impairment in Rats Associated with Changes in Neuronal Firing and Neuroinflammation in the Anterior Cingulate Cortex

Parkinson’s disease (PD) is a complex pathology causing a plethora of non-motor symptoms besides classical motor impairments, including cognitive disturbances. Recent studies in the PD human brain have reported microgliosis in limbic and neocortical structures, suggesting a role for neuroinflammation in the development of cognitive decline. Yet, the mechanism underlying the cognitive pathology is under investigated, mainly for the lack of a valid preclinical neuropathological model reproducing the disease’s motor and non-motor aspects. Here, we show that the bilateral intracerebral infusion of pre-formed human alpha synuclein oligomers (H-αSynOs) within the substantia nigra pars compacta (SNpc) offers a valid model for studying the cognitive symptoms of PD, which adds to the classical motor aspects previously described in the same model. Indeed, H-αSynOs-infused rats displayed memory deficits in the two-trial recognition task in a Y maze and the novel object recognition (NOR) test performed three months after the oligomer infusion. In the anterior cingulate cortex (ACC) of H-αSynOs-infused rats the in vivo electrophysiological activity was altered and the expression of the neuron-specific immediate early gene (IEG) <i<Npas4</i< (Neuronal PAS domain protein 4) and the AMPA receptor subunit GluR1 were decreased. The histological analysis of the brain of cognitively impaired rats showed a neuroinflammatory response in cognition-related regions such as the ACC and discrete subareas of the hippocampus, in the absence of any evident neuronal loss, supporting a role of neuroinflammation in cognitive decline. We found an increased GFAP reactivity and the acquisition of a proinflammatory phenotype by microglia, as indicated by the increased levels of microglial Tumor Necrosis Factor alpha (TNF-α) as compared to vehicle-infused rats. Moreover, diffused deposits of phospho-alpha synuclein (p-αSyn) and Lewy neurite-like aggregates were found in the SNpc and striatum, suggesting the spreading of toxic protein within anatomically interconnected areas. Altogether, we present a neuropathological rat model of PD that is relevant for the study of cognitive dysfunction featuring the disease. The intranigral infusion of toxic oligomeric species of alpha-synuclein (α-Syn) induced spreading and neuroinflammation in distant cognition-relevant regions, which may drive the altered neuronal activity underlying cognitive deficits..

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:11

Enthalten in:

Cells - 11(2022), 17, p 2628

Sprache:

Englisch

Beteiligte Personen:

Maria Francesca Palmas [VerfasserIn]
Michela Etzi [VerfasserIn]
Augusta Pisanu [VerfasserIn]
Chiara Camoglio [VerfasserIn]
Claudia Sagheddu [VerfasserIn]
Michele Santoni [VerfasserIn]
Maria Francesca Manchinu [VerfasserIn]
Mauro Pala [VerfasserIn]
Giuliana Fusco [VerfasserIn]
Alfonso De Simone [VerfasserIn]
Luca Picci [VerfasserIn]
Giovanna Mulas [VerfasserIn]
Saturnino Spiga [VerfasserIn]
Maria Scherma [VerfasserIn]
Paola Fadda [VerfasserIn]
Marco Pistis [VerfasserIn]
Nicola Simola [VerfasserIn]
Ezio Carboni [VerfasserIn]
Anna R. Carta [VerfasserIn]

Links:

doi.org [kostenfrei]
doaj.org [kostenfrei]
www.mdpi.com [kostenfrei]
Journal toc [kostenfrei]

Themen:

α-synuclein
Cognitive impairment
Cytology
Microglia
Neuroinflammation
Neuronal activity
Parkinson’s disease

doi:

10.3390/cells11172628

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

DOAJ084957042