Onaka, T. | Search bioRxiv

bioRxiv2022

Rats emit unique distress calls in social inequality conditions

Humans show aversion toward inequality of social reward, and this aversion plays important roles for the establishment of social cooperation. However, it has remained unknown whether commonly used experimental animals show negative responses to social reward inequality. In this study, we found that rats showed bonding-like behavior to an affiliative human who repeatedly stroked the rats. In addition, these rats emitted distress calls, an index of negative emotion, when an affiliative human stroked another rat in front of them. These distress calls had acoustic characteristics different from those emitted in response to physical stress stimuli such as air-puff. Rats emitted calls with higher frequency (28 kHz) and shorter durations (0.05 sec) in an inequality condition than the frequency and durations of calls emitted when receiving air-puff. Our results suggested that rats exhibited negative emotion with unique distress calls in response to a social inequality condition.

animal behavior and cognition↗

bioRxiv2021

Beneficial effects of the AFO-202 and N-163 strains of Aureobasidium pullulans produced 1,3-1,6 beta glucans on non-esterified fatty acid levels in obese diabetic KKAy mice: A comparative study

Obesity, metabolic syndrome, associated lipotoxicity and its cascade of events contribute to the majority of the burden related to non-communicable diseases globally. Preventive lifestyle changes aside, several beneficial effects have been reported in type II diabetes mellitus and dyslipidaemia patients with biological response modifier glucans (BRMG) produced as an exopolysaccharide by Aureobasidium pullulans. In this study, we compared two strains (AFO-202 and N-163) that produce beta glucans in alleviating lipotoxicity. This study was performed in obese diabetic mice model of KK-Ay mice, in four groups with six subjects in each group - Group 1: sacrificed on Day 0 for baseline values; Group 2: control (drinking water); Group 3: AFO-202 beta glucan--200 mg/kg/day; Group 4: N-163 beta glucan--300 mg/kg/day. The animals in groups 2-4 had the test solutions administered by gavage once daily for 28 consecutive days. Biochemical analyses were conducted of blood glucose, triglycerides, total cholesterol, LDL cholesterol, HDL cholesterol and non-esterified fatty acids (NEFA). Group 4 (N-163) had the lowest NEFA levels, as compared to the other groups, and marginally decreased triglyceride levels. The groups had no significant differences in blood glucose, HbA1c, triglycerides, or LDL and HDL cholesterol. N-163 produced by A. pullulans decreased NEFA in a diabetic mice model in 28 days. These results, although modest, warrant further in-depth research into lipotoxicity and associated inflammatory cascades in both healthy and disease affected subjects to develop novel strategies for prevention and management.

pharmacology and toxicology↗