α-Synuclein aggregation in the olfactory bulb of middle-aged common marmoset

• Published in: Neuroscience research 2016-05, Vol.106, p.55-61
• Main Authors: Kobayashi, Reona, Takahashi-Fujigasaki, Junko, Shiozawa, Seiji, Hara-Miyauchi, Chikako, Inoue, Takashi, Okano, Hirotaka James, Sasaki, Erika, Okano, Hideyuki
• Format: Article
• Language: English
• Subjects: alpha-Synuclein - metabolism; Animals; Brain - metabolism; Callithrix; Callithrix jacchus; Common marmoset; Female; Olfactory bulb; Olfactory Bulb - metabolism; Parkinson's disease; Protein Aggregates; Subcellular Fractions - metabolism; α-Synuclein
• ISSN: 0168-0102; 1872-8111
• DOI: 10.1016/j.neures.2015.11.006

•Aggregation of α-synuclein is detectable in middle-aged marmoset olfactory bulb.•Aggregated α-synuclein is mislocalized in perikarya of olfactory bulb neurons.•α-Synuclein also accumulates in hippocampus of middle-aged marmoset.•We did not observe α-synuclein accumulation in substantia nigra in this age group. The synaptic protein α-synuclein has been identified as a major component of Lewy bodies, a pathological hallmark of Parkinson's disease (PD). Prior to the formation of Lewy bodies, mislocalization and aggregation of the α-synuclein in brain tissue is frequently observed in various neurodegenerative diseases. Aberrant accumulation and localization of α-synuclein are also observed in the aging human brain, for which reason aging is regarded as a risk factor for neurodegenerative disease. To investigate changes in α-synuclein properties in the aging brain, we compared α-synuclein immunoreactivity in brain tissue of young (2-years-old) and middle-aged (6-years-old) common marmoset (Callithrix jacchus). Our analyses revealed marked changes in α-synuclein immunoreactivity in the olfactory bulb of common marmosets of these age cohorts. Perikaryal α-synuclein aggregations were formed in the olfactory bulb in middle-aged animals. We also observed signals of α-synuclein accumulation in hippocampus in this cohort; however, unlike in the olfactory bulb, hippocampal α-synuclein signals were localized in the synaptic terminals. We did not observe either of these features in younger marmosets, which suggest that aging may play a role in these phenomena. Our results using common marmoset brain corresponded with the observation that the α-synuclein aggregations were first occurred from olfactory bulb in human normal aged and PD brain. Therefore, common marmoset is expected as useful model for α-synuclein pathology.