Physiology of vibration-sensitive afferents in the femoral chordotonal organ of the stick insect |
| |
Authors: | W Stein A E Sauer |
| |
Institution: | Abteilung vergleichende Neurobiologie IV, Universit?t Ulm, D-89069 Ulm, Germany e-mail: asauer@uni-ulm.de Fax: +49-731-5022629, DE
|
| |
Abstract: | The femoral chordotonal organ in orthopterans signals proprioceptive sensory information concerning the femur-tibia joint
to the central nervous system. In the stick insect, 80 out of 500 afferents sense tibial position, velocity, or acceleration.
It has been assumed that the other sensory cells in the chordotonal organ would serve as vibration detectors. Extracellular
recordings from the femoral chordotonal organ nerve in fact revealed a sensitivity of the sense organ for vibrations with
frequencies ranging from 10 Hz to 4 kHz, with a maximum sensitivity between 200 and 800 Hz. Single vibration-sensitive afferents
responded to the same range of frequencies. Their spike activity depended on acceleration amplitude and displacement amplitude
of the vibration stimulus. Additionally, 80% of the vibration-sensitive afferents received indirect presynaptic inputs from
themselves or from other afferents of the femoral chordotonal organ, the amplitude of which depended on stimulus frequency
and displacement amplitude. They were associated with a decrease of input resistance in the afferent terminal. From the present
investigation we conclude that the femoral chordotonal organ of the stick insect is a bifunctional sensory organ that, on
the one hand, measures position and movement of the tibia and, on the other hand, detects vibration of the tibia.
Accepted: 6 November 1998 |
| |
Keywords: | Femoral chordotonal organ Presynaptic inhibition Proprioception Stick insect Vibration |
本文献已被 SpringerLink 等数据库收录! |
|