Rhythm Receptive Fields in Striatum of Mice Executing Complex Continuous Movement Sequences

By the use of a novel experimental system, the step-wheel, we investigated the neural underpinnings of complex and continuous movements. We recorded neural activities from the dorsolateral striatum and found neurons sensitive to movement rhythm parameters. These neurons responded to specific combinations of interval, phase, and repetition of movement, effectively forming what we term "rhythm receptive fields." Some neurons even responsive to the combination of movement phases of multiple body parts. In parallel, cortical recordings in sensorimotor areas highlighted a paucity of neurons responsive to multiple parameter combinations, relative to those in the striatum. These findings have implications for comprehending motor coordination deficits seen in brain disorders including Parkinson's disease. Movement encoding by rhythm receptive fields should streamline the brain's capacity to encode temporal patterns, help to resolve the degrees of freedom problem. Such rhythm fields hint at the neural mechanisms governing effective motor control and processing of rhythmic information.

Emergence of rhythmic chunking in complex stepping of mice

Motor chunking is important for motor execution, allowing atomization and efficiency of movement sequences. However, it remains unclear why and how chunks contribute to motor execution. To analyze the structure of naturally occurring chunks, we trained mice to run in a complex series of steps and identified the formation of chunks. We found that intervals (cycle) and the positional relationship between the left and right limbs (phase) of steps inside the chunks, unlike those outside the chunks, were consistent across occurrences. Further, licking by the mice was also more periodic and linked to the specific phases of limb movements within the chunk. Based on these findings, we propose the rhythm chunking hypothesis, whereby within chunks, the repetitive movements of many body parts are linked by the rhythm parameters: cycle and phase. The computational complexity of movement may thereby be reduced by adjusting movements as the combination of rhythms.

[Generation of Gait Rhythm in Mice]

The arrangement of a series of repetitive motions on the time axis should be planned while constructing continuous movement. To understand the mechanism for planning continuous movement and its neural basis, mice were trained to perform complicated continuous step running. The repeated foot movements and neural activities of the animals were recorded. The scaffolding peg arrangement was complex; however, the steps turned out to be more rhythmic, indicating that the mice adjusted to repeat their movements periodically rather than fitting their foot timing with the peg arrangement. In addition, neural activity recorded from the striatum was also found to be rhythmic, suggesting that the striatum may be involved in converting complex inputs into more rhythmic outputs.

A study on the educational significance of special needs education in basis PHN education - 1st report

Background

For public health nurses to support school-aged children with disabilities who live in the community, it is necessary to understand the mechanism of special needs education and learn the inter-professional collaboration that takes place in it. A survey was conducted on school teachers supporting school-aged children with special needs, and the perception of educational significance in basic PHN education and its related factors were examined.

Methods

In December 2019, a survey questionnaire was sent to all 1,052 special needs schools in Japan. Of the 350 respondents, 330 valid replies were analyzed. Regarding the significance of providing special needs education in basic PHN education, we asked for answers on a four-point scale from “strongly agree” to “strongly disagree” and scored 4 to 1 points. Then, unpaired t-tests were performed between every two groups of “school-targeted type of disabilities,” “respondent's position,” and “respondent's perception/experience.” In addition, Pearson's correlation coefficient test was performed on the relationship with the years of teacher experience in special needs schools.

Results

Perception of the significance of providing education was as follows: “school-targeted type of disabilities” refers to school groups with hearing impairments (p < 0.05), “respondent's position” groups are special needs education coordinators (p < 0.05), “respondent's perception/experience” was significantly higher in the group with a high cognition of PHN work (p < 0.05) and in the group with experience of cooperating with PHN (p < 0.001). However, there was no significant correlation with the years of teacher experience in special needs schools.

Conclusions

There was a high perception of the significance of providing education in school groups with hearing impairment and groups with actual coordination experience, especially where early detection and care were particularly required, regardless of years of teacher experience.

Key messages

Special needs education should be included in basic PHN education to promote inter-professional collaboration for improving QOL of school-age children with disabilities living in communities. To foster the foundation for promoting special needs education in basic PHN education, in-service PHNs need to work closely with schools to meet their expectations for PHNs.

Influences of mothers' dieting behaviors on their junior high school daughters

We investigated the influences of mothers' dieting behaviors on their junior high school daughters. We assessed dieting behaviors and eating habits in 221 pairs of mothers and their junior high school daughters using questionnaires. The subjects were classified into an extraordinary-diet (Ex-D) group, who attempted to diet rapidly with unhealthy methods, a structured-diet (St-D) group, who attempted to diet gradually with healthy methods, and a non-diet (N-D) group, using the questionnaire scores. 1) A significant correlation was observed in the distribution of dieting behavior groups between the mothers and their daughters. 2) The scores for dieting behavior of the mothers whose daughters were classified into the Ex-D group were significantly higher in several question items compared with those of the mothers whose daughters were classified into the N-D group. 3) The scores for eating consciousness of the mothers whose daughters were classified into the Ex-D group were significantly lower for the item "Cooking is a fun pastime" compared with those of the mothers whose daughters were classified into the St-D or N-D groups. 4) The number of experiences of conversation with daughters about diet for the mothers whose daughters were in the Ex-D group was significantly higher than that for the mothers whose daughters were classified into the N-D group. The mothers' dieting behavior, eating consciousness, and number of conversations with daughters about diet influenced dieting behaviors in their junior high school daughters. Appropriate education of mothers would be useful to prevent their daughters' inappropriate diet.

[Reproducibility of measurement of intraocular lens location in situ with an anterior eye segment analysis system]

The reproducibility of the measurement (accuracy of repeated measurement) of intraocular lens (IOL) location in situ was studied using an anterior eye segment analysis system (NIDEK EAS-1000). The measurements were performed as follows: (1) errors at photography: 1) errors by the individual photographer 2) errors among three photographers. (2) errors at analysis: 1) errors by individual analysists 2) errors among six analysists. The greatest standard deviation was the accuracy of repeated measurement. Accuracy of repeated measurement (tilt and decentration) was (1) 1) 1.104 degrees, 0.083 mm, (1) 2) 0.866 degrees, 0.072 mm, (2) 1) 0.597 degrees, 0.079 mm, (2) 2) 0.562 degrees, 0.079 mm. From the data obtained in this study, the reproducibility of the EAS-1000 was satisfactory for measurement of IOL location.