Species Composition and Feeding Behaviors of Vector Mosquitoes of Avian Infectious Diseases at a Wild Bird Rehabilitation Facility in Japan.

Although wild bird rehabilitation facilities are important for the conservation of wild species, individuals may be kept within the facilities for long periods, consequently posing a risk for the bird to be infected with pathogens to which they are not naturally exposed. In turn, novel pathogens may be introduced through rescued migratory species. Avian malaria and West Nile fever are important avian diseases transmitted by mosquitoes. To understand the transmission dynamics of such diseases at rehabilitation facilities, the ecology of vector mosquitoes, including species composition, seasonality, and feeding behaviors, were explored. Mosquitoes were collected at a wild bird rehabilitation facility and wildlife sanctuary in Japan from 2019 to 2020 using mouth aspirators, sweep nets, and light traps. A total of 2,819 mosquitoes of 6 species were captured, all of which are potential vectors of avian diseases. Culex pipiens pallens and Cx. pipiens form molestus were the dominant species (82.9% of all collected mosquitoes). Density and seasonality differed between sampling locations, presumably because of differences in mosquito behaviors including feeding preferences and responses to climatic factors. Blood-fed Culex mosquitoes fed solely on birds, and many mosquito species are thought to have fed on birds within the facility. Particularly, Cx. pipiens group probably fed on both rescued and free-living birds. The rehabilitation facility may be an important site for the introduction and spread of pathogens because 1) numerous mosquitoes inhabit the hospital and its surroundings; 2) blood-fed mosquitoes are caught within the hospital; 3) there is direct contact between birds and mosquitoes; 4) both birds within the hospital and wild birds are fed upon. Furthermore, blood-fed Cx. pipiens form molestus were observed in the winter, suggesting that pathogens might be transmitted even during the winter when other mosquito species are inactive.

Response of brain-derived neurotrophic factor to combining cognitive and physical exercise.

PURPOSE: Brain-derived neurotrophic factor (BDNF) is well known for its potential to promote brain plasticity. It has been proposed that combining cognitive and physical exercise (CCPE) may have the potential to generate more synergistic benefits in cognitive function than either cognitive exercise (CE) or physical exercise (PE) alone. The purpose of this study was to examine acute responses of peripheral BDNF levels and cognitive performance to CE, PE, and CCPE. METHODS: Thirteen healthy adult men participated in four experimental sessions; a 30-min CE, a 30-min cycling PE at an intensity of 60% peak oxygen uptake, a 30-min CCPE at the same intensity as PE, and a 30-min session of complete rest. Plasma BDNF levels and cognitive performance were measured before and after each session. RESULTS: Both PE and CCPE significantly increased plasma BDNF levels (p < .05). CE led to no significant increase (p ≥ .05), and there was no significant difference in peripheral BDNF levels between PE and CCPE (p ≥ .05). No session induced a significant change in cognitive performance (p ≥ .05). CONCLUSIONS: Our study suggests that CE and PE have different responses of peripheral BDNF levels and that CCPE had no additional or synergistic effect on peripheral BDNF levels compared with PE alone. This study offers further insights into the potential mechanisms underlying the respective roles of CE, PE, and CCPE for peripheral BDNF levels and cognitive performance.

Effect of Neuromuscular Electrical Stimulation on Brain-derived Neurotrophic Factor.

Brain-derived neurotrophic factor (BDNF) has been considered an essential mediator responsible for the beneficial effects of physical activity in preventing cognitive impairment. This study aimed at examining the effects of a single bout of neuromuscular electrical stimulation (NMES) on levels of BDNF in the plasma and on cognitive performance in healthy adult men. Thirteen healthy adult men participated in three experimental sessions. The first session was 30 min of NMES to both legs, the second was 30 min of cycling exercise at the intensity of 60% peak oxygen uptake, and the third was 30 min of complete rest. Blood was examined for plasma BDNF levels and glucose concentrations, and cognitive performance tests were performed before and after each session. A single bout of NMES significantly increased plasma BDNF levels (p<0.05), which were equivalent to the amount of plasma BDNF released during the exercise session (p>0.05). However, there were no significant changes in cognitive performance between the sessions (p>0.05). The present study found that a single bout of NMES significantly increased plasma BDNF to levels normally present during moderate voluntary exercise. Therefore, NMES could serve as an alternative method of exercise, and might shed light on individuals for whom voluntary physical exercise is contraindicated.

Transient and sustained effects of an auditory accessory stimulus in a visual go/no go task.

The present study examined the facilitation effects of an auditory accessory stimulus that was irrelevant to a visual reaction time (RT) task as a function of stimulus onset asynchrony between the accessory stimulus and the visual target stimulus. Results of the present experiment showed that the auditory accessory stimulus caused two variations of RT, short-term and long-term, that were distinguished on the basis of stimulus onset asynchrony. This finding suggested that effects of an accessory stimulus consisted of two qualitatively different facilitations. The Transient Facilitation appeared instantly after the onset of the accessory stimulus and then soon decayed, and the Sustained Facilitation increased and decreased more gradually than the former.