Correlations between serum levels of beta amyloid, cerebrospinal levels of tau and phospho tau, and delayed response tasks in young and aged cynomolgus monkeys (Macaca fascicularis)

Abstract

Circulating Aβ42 levels were lower in Aged monkeys and were correlated with inferior performance on delayed response tasks in Aged animals; therefore, both measures may be useful in establishing cynomolgus monkeys as models for studies of AD.

Granulovacuolar Degeneration in Brains of Senile Cynomolgus Monkeys

“…Our studies of cynomolgus monkeys have identified an age-related decline in DRT performance (Darusman et al, 2013a). We also found that DRT performance was correlated with circulating levels of amyloid-beta (Aβ) levels (Aβ—specifically Aβ 42 ; Darusman et al, 2013b; Yue et al, 2014). Expanding our study, we found indications that structural magnetic resonance imaging could be used to identify abnormalities, such as atrophy in the hippocampus and cortical areas, in aged monkeys with poor memory and low circulating Aβ 42 levels (Darusman et al, 2014b).…”

Amyloid Beta1–42 and the Phoshorylated Tau Threonine 231 in Brains of Aged Cynomolgus Monkeys (Macaca fascicularis)

“…From previous studies, we selected aged subjects above 20 years old that met the requirements of low levels of Aβ 42 (<5000 pg/ml) and low DRT performance (<40%) for the memory-affected group (Darusman et al, 2013a,b). Aged subjects characterized by high-circulating Aβ 42 and high DRT performance were selected for the age-matched control group.…”

“… Data are collected from the references Darusman et al (2013a,b). DRT performance is presented as the collected percent of trials where the subject could correctly retrieve a hidden item following a predetermined delay.…”

“…The DRT performance was correlated with the levels of the core biomarkers indicative of AD, especially the amyloid-beta 1–42 (Aβ 42 ) (Darusman et al, 2013b, 2014), where the DRT performance was positively correlated with concentrations of Aβ 42 . Structural magnetic resonance imaging (MRI) studies identified abnormalities, such as atrophy in hippocampus and morphological changes in the cortical areas in aged monkeys with poor memory and low Aβ 42 levels (Darusman et al, 2014).…”

“…In the present study, we examined the presence of Aβ 42 and the p-tau by immunohistochemistry analysis in brain sections of aged monkeys selected from a previous study (Darusman et al, 2013a,b), based on low total DRT and low levels of Aβ 42 in cerebrospinal fluid (CSF) compared with aged monkeys with better memory performance and high CSF Aβ 42 levels. The DRT were assessed by the short term memory test (STMT), long term memory test (LTMT), and memory load test (MLT).…”