一般口演（若手道場）

一般口演（若手道場）若手道場　運動系 Wakate Dojo: Movement Themes 座長：田中謙二（慶應義塾大学）・笠井淳司（大阪大学大学院薬学研究科）

2022年7月1日　15:00～15:15　沖縄コンベンションセンター会議場B3・4　第6会場 2WD06a2-01 プロドライバーは競技パフォーマンスに応じて瞬目を制御する Professional drivers modulate blink timings depending on racing performance 西薗良太(1)、西條直樹(1)、柏野牧夫(1) 1. NTTコミュニケーション科学基礎研究所 Ryota Nishizono(1), Naoki Saijo(1), Makio Kashino(1) 1. NTT Communication Science Laboratories Keyword: eye blink, eye metrics, car driving, in-the-wild data Eyeblink, though usually unnoticed, occurs frequently and temporally blocks up to 10% of vision input. Blink timings or blink generation probability are susceptible to cognitive functions and sensory inputs. Especially, when repeating a visuomotor task in which temporary loss of visual information over the eyeblink span is critical, humans modulated their eyeblink generation probability (Hoppe et al., PNAS, 2018). However, there is little information on the applicability of this knowledge in real field tasks. Moreover, if effective in real field tasks, hard-to-reach cognitive functions and the effect of sensory input could be estimated by eyeblink metrics. Herein, as a preliminary study to assess this possibility, we investigated the eyeblink features of elite drivers during real races across several circuits. We simultaneously acquired eye images and car behavior during race driving using a modified helmet-mounted eye tracker and car data logger installed in the car, respectively. The measurement was a naturalistic observation—the participants drove for their own jobs (car testing and training) and not specifically for our study. The eyeblink timings were extracted using convolutional neural network image classification techniques. We examined eyeblink locations along a course as notable driving events corresponded with geographical locations. The results showed that, although the eyeblink rate—a classical eyeblink metric—did not consistently correlate with lap time performance, eyeblink location patterns emerged depending on racing performance, individuals, and courses. The within-individual pattern was statistically more synchronized during faster laps. Despite 100%+ differences in average eyeblink frequency per lap, the patterns were significantly similar across individuals in each course. These findings provide evidence of location-wise eyeblink modulation by elite drivers during actual circuit racing. The location on the course might not be only factor for eyeblink modulation because the eyeblink pattern was also sensitive to the driving performance. Previous studies on eyeblinks have either been fully controlled laboratory studies or studies on crude changes in eyeblink rate in real field tasks; in contrast, this study suggests that simultaneous recording of detailed eyeblink metrics and behaviors may reveal untouched cognitive state dynamics in the wild.		2022年7月1日　15:15～15:30　沖縄コンベンションセンター会議場B3・4　第6会場 2WD06a2-02 ゼブラフィッシュ幼魚における微細な姿勢制御の力学的・神経回路メカニズムの解明 Kinetics and neural circuit mechanisms of a fine postural control in larval zebrafish 椙岡拓己(1,2)、谷本昌志(2,1)、東島眞一(2,1) 1. 総合研究大学院大学、2. 自然科学研究機構　基礎生物学研究所 Takumi Sugioka(1,2), Masashi Tanimoto(2,1), Shin-ichi Higashijima(2,1) 1. The Graduate University for Advanced Studies, SOKENDAI, 2. Natianl Institutes of Natural Science, National Institute for Basic Biology Keyword: zebrafish, posture, kinetics, neural circuit Land-walking animals keep balanced posture by continuously controlling their anti-gravity muscles in response to fluctuations of the body position. Some aquatic animals maintain upright posture without swimming, suggesting that they have a fine behavioral mechanism to keep balanced posture. However, kinetics and neural mechanisms of this behavior have been largely unknown. We focused on a fine postural control in the roll direction without swimming in larval zebrafish. By observing the behavior during roll-tilt, we found that fish return to the upright posture with a slight body bend to the upper side at the rostral body (hereafter referred to as "rostral body bend" or “RBB”). The RBB was more pronounced and persistent when fish were placed in highly viscous water or head-embedded in agarose. In a simplified model, when a fish is upright, the gravity and the buoyancy are antiparallel on the same axis. In contrast, when a fish performs the RBB upon the roll tilt, the center of gravity moves laterally more than the center of buoyancy does, because the RBB shifts the caudal body while the swim bladder position remains mostly unchanged. This results in a lateral shift of the gravitational force, generating a torque that counter-rotates the tilted body to recover the upright posture. If this model is correct, swim bladder-deflated fish would not be able to recover from the tilted posture, because the gravity and the buoyancy are always antiparallel on the same axis even when fish perform the RBB. As expected, swim bladder-deflated fish were unable to recover their posture and continued the RBB during tilt. Next, we focused on the neural mechanisms of the RBB. Previous studies reported that an RBB-like behavior was triggered by an artificial vestibular input or stimulation of nucleus of the medial longitudinal fasciculus (nMLF). Because the nMLF receives axonal projections from the contralateral tangential nucleus (TAN) and the nMLF stimulation activated posterior hypaxial muscle (PHM) at the rostral body, we hypothesized TAN-nMLF-PHM pathway drives the RBB. Indeed, we proved this hypothesis by performing Ca²⁺ imaging during the tilt and cell ablation experiments. In summary, the present study suggests that fish continuously keep the upright posture in the roll direction by performing the RBB with the TAN-nMLF-PHM pathway, revealing a posture-maintaining mechanism in an aquatic animal.

2022年7月1日　15:30～15:45　沖縄コンベンションセンター会議場B3・4　第6会場 2WD06a2-03 Change in behavioral context alters the population of neurons representing the behavioral information in primate medial prefrontal cortex Muhammad Ali Haider Awan(1), Hajime Mushiake(1), Yoshiya Matsuzaka(2) 1. Tohoku University, 2. Tohoku Medical and Pharmaceutical University Keyword:* pmPFC, medial prefrontal, tactics, sensorimotor The central nervous systems of higher mammals are able to simultaneously learn and perform wide array of complex behaviors. A question arises about how the neural representations of multiple tasks coexist within the same neural network. Do neurons playing a particular role (e.g. working memory) under a particular behavioral condition change their functions across different conditions? Or, alternatively, do different sets of neurons take part in a particular function across different conditions? To address this question, we examined neuronal activity in medial prefrontal cortex of primates while they were performing two versions of arm-reaching tasks which required selection of multiple behavioral tactics (i.e. internal protocol of sensorimotor transformations), a critical requirement known to activate this area.Both tasks required the monkeys to transform the visually instructed spatial cue (either left or right) into the direction of arm reaching (either left or right). This transformation was done under the two different tactics: either pro-reach (reach toward the spatial cue) or anti-reach (reach away from the spatial cue) which were pseudo-randomly determined in every trial. The spatial cue was given ahead of the tactics cue in location-precued trials, whereas in the tactics-precued trials, the order was reversed.During the performance of these tasks, neurons in the posterior medial prefrontal cortex (pmPFC) were activated selectively for the tactics, location of the spatial cue, action or their combinations. Surprisingly, in 70% of the selective neurons, the tactics-selective activity appeared in a particular task: i.e. in either tactics- or location-precued task but not in both. Such task-specific neuronal representation appeared in 75% of the action-selective neurons. And finally, all the cue-location selective neurons showed such activity exclusively in one task but not in both. Our finding indicates that, in this area, mostly non-overlapping populations of neurons encode relevant behavioral factors across various contexts		2022年7月1日　15:45～16:00　沖縄コンベンションセンター会議場B3・4　第6会場 2WD06a2-04 Grasping with the tongue: Cerebellar control of adaptive tongue kinematics in mice Mohamed M.K. El Tabbal(1), Cedric Galetzka(1), Sara Parnell(1), Bernd Kuhn(1) 1. Optical neuroimaging unit, Okinawa Institute of Science and Technology, Okinawa Japan. Keyword:* Tongue, Cerebellum , Senseriomotor, Interception Precise spatiotemporal control of the tongue is essential in diverse animal behaviors across species such as catching prey and vocalization. Recent studies have started to unravel complex rodent tongue trajectories during licking including cortex-dependent corrective submovements. However, a description of the cerebellar influence on complex tongue kinematics on a millisecond scale is still lacking. Here we present a novel behavioral task that requires head-fixed mice to intercept a laterally approaching food pellet with their tongue. We combined high-speed videography with deep learning methods to retrieve tongue trajectories during interception. In addition, we performed one-photon calcium imaging of populations of Purkinje neurons during behavior. Our results show that mice optimize tongue speed and movement onset time as they learn to intercept moving food pellets at varying approach speeds. We demonstrate via pharmacological inactivation that these adaptive tongue movements are dependent on cerebellar networks in Crus I and II. The results support an emerging consensus that the rodent tongue shows distinct phases of motor action during reaching and grasping akin to limb reaching. We consider our behavioral task as a stepping stone to investigate the neural basis of fast adaptive motor kinematics during object interception. Follow-up studies could combine our task with kilohertz voltage imaging of Purkinje neurons. Furthermore, differences in motor adaptation and tongue trajectories can be analyzed for different genotypes such as transgenic mice that carry genes relevant for speech.