| Project/Area Number |
15570065
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Animal physiology/Animal behavior
|
|---|
| Research Institution | Ehime University |
|---|
Principal Investigator |
KANOU Masamichi Ehime University, Faculty of Science, Associate Professor, 理学部, 助教授 (80183276)
|
|---|
| Project Period (FY) |
2003 – 2005
|
| Project Status |
Completed (Fiscal Year 2005)
|
| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2005: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2004: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2003: ¥2,300,000 (Direct Cost: ¥2,300,000)
|
|---|
| Keywords | cricket / air current sense / cercus / escape behavior / behavioral compensation / giant interneuron |
|---|
| Research Abstract |
A pair of appendages called cerci at the abdominal end and mechanosensitive filiform hairs on them are responsible for the wind-evoked escape behavior of the cricket, Gryllus bimaculatus. Unilateral cercal ablation causes misoriented escape in the cricket. The directionality of the escape of unilaterally cercus-ablated crickets, however, shows a compensational recovery after about 2 weeks of rearing. The aim of this study is to clarify that the stimulation of filiform hairs on the remaining cercus by a self-generated wind caused by walking and the efference copy signal for the walking are necessary for the behavioral compensation. Neural recordings from ventral nerve cords (VNCs) permitted us to observe rhythmical bursts of descending neurons during walking. During brisk walking, the burst frequency was large and vice versa. This means that walking velocity is encoded into the burst frequency of descending neurons. To clarify that the bursting of descending neurons is an efference copy
… More
signal but not the activity of sensory neurons resulted from the self-stimulation caused by the walking, we made a simultaneously recording of neural activities and the motion of a cricket. The bursting of descending neurons preceded any motion of the cricket by about 63 ms. Moreover, it preceded the motion of any leg of a cricket by about 197 ms. Therefore, it was proved that the bursting of descending neurons was not resulted by the motion of a cricket but was generated before the any motion of a cricket.
During the recovery period after unilateral cercal ablation, the effectiveness of walking on the compensational recovery in the escape direction was investigated. The walking experienced in relatively early period wa more effective for the compensation than that experienced in later period. As the effectiveness of walking on the behavioral compensation thus changes during the recovery period, a critical period may exist for the change of the neural system that controls the escape direction. Less
|
