[Behavioral and physiological responses to hypoxia stress in male and female Macrobrachium rosenbergii]. / 雌雄罗氏沼虾应对低氧胁迫的行为生理响应.

To explore the physiological and behavioral responses of male and female Macrobrachium rosenbergii under hypoxia stress, an experiment with three dissolved oxygen (DO) levels (6.46, 4.48 and 3.27 mg·L-1, 6.46 mg·L-1 as control) was conducted. The enzyme activities of energy metabolism in hepatopancreas and muscles of male and female M. rosenbergii were measured after six days of hypoxia stress. The results showed that the enzyme activities of aerobic metabolism in muscles and swimming abilities were significantly decreased as DO decreased from 6.46 mg·L-1 to 4.48 mg·L-1, with the decreases being less in males than females. There was no significant difference in enzyme activities of anaerobic metabolism. When DO was further decreased to 3.27 mg·L-1, the enzyme activities of aerobic metabolism and anaerobic metabolism in muscles significantly decreased. The activity of lactate dehydrogenase (LDH) in anaerobic metabolism of hepatopancreas and tail-flipping speeds significantly decreased in males and females, with less decrease in females than that in males for LDH activity of hepatopancreas. The swimming ability was positively correlated with the enzyme activities of aerobic metabolism in pleopods muscles. There was significant correlation between tail-flipping abilities and enzyme activities of anaerobic metabolism. M. rosenbergii could reduce its reliance on energy metabolism during hypoxia stress, but with negative consequences on locomotor abilities. The muscles were preferentially powered to meet energy requirements of locomotion in males, while females gave priority to energy supply for hepatopancreas under insufficient oxygen conditions.

Changes in Spatial Working Memory in Stable Chronic Obstructive Pulmonary Disease: A Retrospective Study.

Chronic obstructive pulmonary disease (COPD) is characterized by irreversible airflow limitation and is often accompanied by cognitive impairment. Little is known about the working memory of COPD patients. The aim of the study is to evaluate the spatial working memory of COPD patients using the classical visuospatial working memory neuropsychological paradigms. This was a retrospective study of patients with COPD who were evaluated for neurocognitive functions between February and December 2018 at Hefei Second People's Hospital. Healthy controls (HC) were included. The neuropsychological tests included the Beijing Version of the Montreal Cognitive Assessment Test (MoCA), digit span test (DS), Chinese Auditory Verbal Learning Test (CAVLT), Stroop test, and Verbal Fluency Test (VFT). The COPD group performed worse in MoCA (22.3 ± 4.5 vs. 26.1 ± 2.9, P < 0.001), Stroop interference test (44.2 ± 16.9 vs. 36.8 ± 10.3, P = 0.038), and VFT (12.9 ± 2.8 vs. 15.3 ± 4.7, P = 0.021) vs. the HC group. Compared with the HC group, COPD patients had statistically significant differences with respect to 0-back RT (657 ± 46 vs. 578 ± 107, P = 0.001), 1-back accuracy (41.8 ± 12.1% vs. 81.5 ± 18.1%, P < 0.001), 1-back RT (592 ± 75 vs. 431 ± 138, P < 0.001), 2-back accuracy (31.4 ± 9.9% vs. 68.1 ± 16.6%, P < 0.001), and 2-back RT (563 ± 79 vs. 455 ± 153, P = 0.002). Only PaO2 was independently associated with 0-back RT (B = 0.992 ± 0.428, P = 0.028) and 1-back ACC (B = 0.003 ± 0.001, P = 0.004). COPD patients exhibit impairment in working memory and executive function, but not in short- or long-term memory. The impairment of working memory in a patient with COPD may be more due to integrate memory information rather than to memory information storage. COPD patients exhibit a frontal-type cognitive decline.