Differences in male Aedes aegypti and Aedes albopictus hearing systems facilitate recognition of conspecific female flight tones.

When Aedes albopictus mosquitoes invade regions predominated by Aedes aegypti, either the latter can be displaced or the species can coexist, with potential consequences on disease transmission. Males from both species identify females by listening for her flight sounds. Comparing male hearing systems may provide insight into how hearing could prevent interspecific mating. Here, we show that species-specific differences in female wing beat frequencies are reflected in differences in male ear mechanical tuning frequencies and sound response profiles. Though Aedes albopictus males are attracted to sound, they do not readily display abdominal bending, unlike Aedes aegypti. We observed interspecific differences in male ear mechanical, but not electrical, tuning, suggesting a conserved primary auditory processing pathway. Our work suggests a potential role for hearing in the premating isolation of Aedes aegypti and Aedes albopictus, with implications for predicting future dynamics in their sympatric relationships and our understanding of mosquito acoustic communication.

Evolutionary conservation and diversification of auditory neural circuits that process courtship songs in Drosophila.

Acoustic communication signals diversify even on short evolutionary time scales. To understand how the auditory system underlying acoustic communication could evolve, we conducted a systematic comparison of the early stages of the auditory neural circuit involved in song information processing between closely-related fruit-fly species. Male Drosophila melanogaster and D. simulans produce different sound signals during mating rituals, known as courtship songs. Female flies from these species selectively increase their receptivity when they hear songs with conspecific temporal patterns. Here, we firstly confirmed interspecific differences in temporal pattern preferences; D. simulans preferred pulse songs with longer intervals than D. melanogaster. Primary and secondary song-relay neurons, JO neurons and AMMC-B1 neurons, shared similar morphology and neurotransmitters between species. The temporal pattern preferences of AMMC-B1 neurons were also relatively similar between species, with slight but significant differences in their band-pass properties. Although the shift direction of the response property matched that of the behavior, these differences are not large enough to explain behavioral differences in song preferences. This study enhances our understanding of the conservation and diversification of the architecture of the early-stage neural circuit which processes acoustic communication signals.

Serotonin modulation in the male Aedes aegypti ear influences hearing.

Male Aedes aegypti (Ae. aegypti) mosquitoes rely on hearing to identify conspecific females for mating, with the male attraction to the sound of flying females ("phonotaxis") an important behavior in the initial courtship stage. Hearing thus represents a promising target for novel methods of mosquito control, and hearing behaviors (such as male phonotaxis) can be targeted via the use of sound traps. These traps unfortunately have proven to be relatively ineffective during field deployment. Shifting the target from hearing behavior to hearing function could therefore offer a novel method of interfering with Ae. aegypti mating. Numerous neurotransmitters, including serotonin (5-hydroxytryptamine, or 5-HT) and octopamine, are expressed in the male ear, with modulation of the latter proven to influence the mechanical responses of the ear to sound. The effect of serotonin modulation however remains underexplored despite its significant role in determining many key behaviors and biological processes of animals. Here we investigated the influence of serotonin on the Ae. aegypti hearing function and behaviors. Using immunohistochemistry, we found significant expression of serotonin in the male and female Ae. aegypti ears. In the male ear, presynaptic sites identified via antibody labelling showed only partial overlap with serotonin. Next, we used RT-qPCR to identify and quantify the expression levels of three different serotonin receptor families (5-HT1, 5-HT2, and 5-HT7) in the mosquito heads and ears. Although all receptors were identified in the ears of both sexes, those from the 5-HT7 family were significantly more expressed in the ears relative to the heads. We then thoracically injected serotonin-related compounds into the mosquitoes and found a significant, reversible effect of serotonin exposure on the male ear mechanical tuning frequency. Finally, oral administration of a serotonin-synthesis inhibitor altered male phonotaxis. The mosquito serotonergic system and its receptors thus represent interesting targets for novel methods of mosquito, and thus disease, control.

Relationship between Activities of Daily Living of Home-Based Rehabilitation Users and Caregiver Burden-Induced Depression: A Retrospective Study.

This study was aimed at determining the cutoff values of activities of daily living (ADL) and the combination of related factors associated with high caregiver burden that induces depression among caregivers. The study participants included 50 pairs of home-based rehabilitation users and their primary caregivers. They were classified into two groups: high-burden and low-burden groups according to the short version of the Japanese version of the Zarit Caregiver Burden Interview score of ≥13 or ≤12, respectively. The cutoff values of ADL and the combination of related factors associated with high caregiver burden were examined using the receiver operating characteristic curve and decision tree analyses. The cutoff value associated with high caregiver burden was 5 points for the controlling bladder item of the Barthel index (BI) (sensitivity: 90%, specificity: 70%). Regarding the decision tree, the controlling bladder item of BI (≤5 or 10 points) was selected as the first layer and the recipient's age (≤78 or ≥79 years) as the second layer. High caregiver burden was identified in 85.7% of the caregivers in whom the score of controlling bladder of BI was ≤5 points and the patient was aged ≤78 years. A score of ≤5 points for the controlling bladder item of BI along with young recipient age was associated with high caregiver burden that induces depression among caregivers. This approach is useful to identify caregivers with high caregiver burden who are at risk for depression.

Effect of life-space mobility on subjective well-being in aged home-based rehabilitation users with different levels of independence in activities of daily living.

[Purpose] The relationship between quality of life and life-space mobility in community-dwelling older adults has recently been reported. The present study aimed to elucidate this relationship in home-based rehabilitation users with limited life-space mobility and loss of independence in activities of daily living. [Participants and Methods] The study population comprised 33 home-based rehabilitation users. The participants were expected to have a wide range of the level of independence in activities of daily living; therefore, they were categorized into three groups according to the Barthel Index score: independent (95-100 points), moderately disabled (90-65 points), and severely disabled (60-0 points) groups. We examined the relationships among the Philadelphia Geriatric Center Morale Scale, Life-Space Assessment, and Barthel Index scores and age. [Results] We detected a strong positive correlation between the Philadelphia Geriatric Center Morale Scale and Life-Space Assessment scores in the independent group; however, no significant correlations were observed in the moderately and severely disabled groups. [Conclusion] Our findings suggest a relationship between subjective well-being and life-space mobility in home-based rehabilitation users who are mostly independent in activities of daily living. However, owing to the small sample size and characteristics of the scales used in this study, further studies are warranted to verify these results.

Amount of balance necessary for the independence of transfer and stair-climbing in stroke inpatients.

PURPOSE: The purpose of this study was to clarify the amount of balance necessary for the independence of transfer and stair-climbing in stroke patients. METHOD: This study included 111 stroke inpatients. Simple and multiple regression analyses were conducted to establish the association between the FIM® instrument scores for transfer or stair-climbing and Berg Balance Scale. Furthermore, receiver operating characteristic curves were used to elucidate the amount of balance necessary for the independence of transfer and stair-climbing. RESULT: Simple and multiple regression analyses showed that the FIM® instrument scores for transfer and stair-climbing were strongly associated with Berg Balance Scale. On comparison of the independent and supervision-dependent groups, Berg Balance Scale cut-off values for transfer and stair-climbing were 41/40 and 54/53 points, respectively. On comparison of the independent-supervision and dependent groups, the cut-off values for transfer and stair-climbing were 30/29 and 41/40 points, respectively. CONCLUSIONS: The calculated cut-off values indicated the amount of balance necessary for the independence of transfer and stair-climbing, with and without supervision, in stroke patients. Berg Balance Scale has a good discriminatory ability and cut-off values are clinically useful to determine the appropriate independence levels of transfer and stair-climbing in hospital wards. Implications for rehabilitation The Berg Balance Scale's (BBS) strong association with transfer and stair-climbing independence and performance indicates that establishing cut-off values is vitally important for the established use of the BBS clinically. The cut-off values calculated herein accurately demonstrate the level of balance necessary for transfer and stair-climbing independence, with and without supervision, in stroke patients. These criteria should be employed clinically for determining the level of independence for transfer and stair-climbing as well as for setting balance training goals aimed at improving transfer and stair-climbing.

Relationship between Grooming Performance and Motor and Cognitive Functions in Stroke Patients with Receiver Operating Characteristic Analysis.

BACKGROUND: This study aimed to elucidate the relationship between grooming performance of stroke patients and various motor and cognitive functions and to examine the cognitive and physical functional standards required for grooming independence. METHODS: We retrospectively analyzed the data of 96 hospitalized patients with first stroke in a rehabilitation hospital ward. Logistic regression analysis and receiver operating characteristic curves were used to investigate the related cognitive and motor functions with grooming performance and to calculate the cutoff values for independence and supervision levels in grooming. RESULTS: For analysis between the independent and supervision-dependent groups, the only item with an area under the curve (AUC) of .9 or higher was the Berg Balance Scale, and the calculated cutoff value was 41/40 (sensitivity, 83.6%; specificity, 87.8%). For analysis between the independent-supervision and dependent groups, the items with an AUC of .9 or higher were the Simple Test for Evaluating Hand Function (STEF) on the nonaffected side, Vitality Index (VI), and FIM® cognition. The cutoff values were 68/67 for the STEF (sensitivity, 100%; specificity, 72.2%), 9/8 points for the VI (sensitivity, 92.3%; specificity, 88.9%), and 23/22 points for FIM® cognition (sensitivity, 91.0%; specificity, 88.9%). CONCLUSIONS: Our results suggest that upper-extremity functions on the nonaffected side, motivation, and cognitive functions are particularly important to achieve the supervision level and that balance is important to reach the independence level. The effective improvement of grooming performance is possible by performing therapeutic or compensatory intervention on functions that have not achieved these cutoff values.

Identification of the affected lower limb and unaffected side motor functions as determinants of activities of daily living performance in stroke patients using partial correlation analysis.

[Purpose] This study aimed to clarify the independent impact of the affected upper and lower limb, trunk, and unaffected side motor functions on activities of daily living in stroke patients using partial correlation analysis. [Subjects and Methods] This retrospective study included 77 stroke patients. Motor functions were assessed using the Stroke Impairment Assessment Set, and the activities of daily living performance was assessed using the Barthel index or Functional Independence Measure. Further, simple and partial correlation analyses were conducted between each motor function and activities of daily living parameter. [Results] Simple correlation analysis identified significant positive correlations for each pair. In contrast, partial correlation analysis only identified significant positive correlations between the affected lower limb or unaffected side functions and the Barthel index or Functional Independence Measure. This discrepancy between the two tests was explained by the significant interaction between the affected upper and lower limb functions and between the trunk and unaffected side functions. [Conclusion] The present study identified the affected lower limb and unaffected side motor functions as the major determinants of activities of daily living performance in stroke patients. These findings suggest that rehabilitation programs can be improved by targeting these areas.

Contribution of abdominal muscle strength to various activities of daily living of stroke patients with mild paralysis.

[Purpose] The trunk muscles frequently become weak after stroke, thus impacting overall activities of daily living. However, activities of daily living items closely related with trunk strength remain unclear. This study aimed to clarify the influence of trunk muscle weakness on activities of daily living items. [Subjects] The subjects were 24 stroke patients who fulfilled the following inclusion criteria: first stroke and the absence of severe paralysis, marked cognitive function deterioration, unilateral spatial neglect or apathy. [Methods] According to abdominal strength, the 24 patients were divided into a nonweakness group and a weakness group. For the assessment, we used the stroke impairment assessment set, the Berg balance scale, a simple test for evaluating hand function, grip strength, and functional independence measure scale scores and the results were compared between the groups. [Results] The Berg balance scale score and scores for dressing, toilet use, transfer to bed, and walk items of the functional independence measure were significantly lower in the weakness group than in the nonweakness group. [Conclusion] Our results suggest that weakness of the abdominal muscles adversely impacts the balance of patients with mild stroke as well as their ability to dress, use a toilet, transfer, and walk. Trunk training, including abdominal muscle exercises, can effectively improve the performance of these activities of daily living items.