Background: We have been performing a canalith repositioning procedure for benign paroxysmal positional vertigo. When we adopted the Epley maneuver for posterior semicircular canal type, and affected-ear-up 90° m...Background: We have been performing a canalith repositioning procedure for benign paroxysmal positional vertigo. When we adopted the Epley maneuver for posterior semicircular canal type, and affected-ear-up 90° maneuver for lateral semicircular canal type, we noticed that no nystagmus occurred in the sitting position just after treatment. Despite direct excitation to the utricle by the pathological debris, none of the subjects complained of dizziness. Thus, we hypothesized that nystagmus and dizziness do not occur by stimulation of the otolith organs. Objective: The aim of the study was to observe and record the eye movements induced by the otolith organs to confirm our hypothesis. Materials and Methods: Twelve healthy humans were tested. In the sitting position, the head was tilted to the right ear by 45° and vice versa. Afterward, the head was bent forward by 90° (nose-down), and the subject’s seat was reclined to the head-hanging position. Each position was kept for five seconds. We interviewed the subjects to assess their dizziness. Results: None of the subjects showed nystagmus and complained of dizziness in every position. Conclusions: Nystagmus does not occur by the stimulation to the otolith organs;therefore, ocular counter-rolling is a semicircular canal ocular reflex.展开更多
The plainfin midshipman fish(Porichthys notatus Girard,1854)is a vocal species of batrachoidid fish that gen-erates acoustic signals for intraspecific communication during social and reproductive activity and has beco...The plainfin midshipman fish(Porichthys notatus Girard,1854)is a vocal species of batrachoidid fish that gen-erates acoustic signals for intraspecific communication during social and reproductive activity and has become a good model for investigating the neural and endocrine mechanisms of vocal-acoustic communication.Reproduc-tively active female plainfin midshipman fish use their auditory sense to detect and locate“singing”males,which produce a multiharmonic advertisement call to attract females for spawning.The seasonal onset of male adver-tisement calling in the midshipman fish coincides with an increase in the range of frequency sensitivity of the female’s inner ear saccule,the main organ of hearing,thus leading to enhanced encoding of the dominant frequency components of male advertisement calls.Non-reproductive females treated with either testosterone or 17β-estradiol exhibit a dramatic increase in the inner ear’s frequency sensitivity that mimics the reproductive fe-male’s auditory phenotype and leads to an increased detection of the male’s advertisement call.This novel form of auditory plasticity provides an adaptable mechanism that enhances coupling between sender and receiver in vocal communication.This review focuses on recent evidence for seasonal reproductive-state and steroid-dependent plasticity of auditory frequency sensitivity in the peripheral auditory system of the midshipman fish.The potential steroid-dependent mechanism(s)that lead to this novel form of auditory and behavioral plasticity are also dis-cussed.展开更多
文摘Background: We have been performing a canalith repositioning procedure for benign paroxysmal positional vertigo. When we adopted the Epley maneuver for posterior semicircular canal type, and affected-ear-up 90° maneuver for lateral semicircular canal type, we noticed that no nystagmus occurred in the sitting position just after treatment. Despite direct excitation to the utricle by the pathological debris, none of the subjects complained of dizziness. Thus, we hypothesized that nystagmus and dizziness do not occur by stimulation of the otolith organs. Objective: The aim of the study was to observe and record the eye movements induced by the otolith organs to confirm our hypothesis. Materials and Methods: Twelve healthy humans were tested. In the sitting position, the head was tilted to the right ear by 45° and vice versa. Afterward, the head was bent forward by 90° (nose-down), and the subject’s seat was reclined to the head-hanging position. Each position was kept for five seconds. We interviewed the subjects to assess their dizziness. Results: None of the subjects showed nystagmus and complained of dizziness in every position. Conclusions: Nystagmus does not occur by the stimulation to the otolith organs;therefore, ocular counter-rolling is a semicircular canal ocular reflex.
文摘The plainfin midshipman fish(Porichthys notatus Girard,1854)is a vocal species of batrachoidid fish that gen-erates acoustic signals for intraspecific communication during social and reproductive activity and has become a good model for investigating the neural and endocrine mechanisms of vocal-acoustic communication.Reproduc-tively active female plainfin midshipman fish use their auditory sense to detect and locate“singing”males,which produce a multiharmonic advertisement call to attract females for spawning.The seasonal onset of male adver-tisement calling in the midshipman fish coincides with an increase in the range of frequency sensitivity of the female’s inner ear saccule,the main organ of hearing,thus leading to enhanced encoding of the dominant frequency components of male advertisement calls.Non-reproductive females treated with either testosterone or 17β-estradiol exhibit a dramatic increase in the inner ear’s frequency sensitivity that mimics the reproductive fe-male’s auditory phenotype and leads to an increased detection of the male’s advertisement call.This novel form of auditory plasticity provides an adaptable mechanism that enhances coupling between sender and receiver in vocal communication.This review focuses on recent evidence for seasonal reproductive-state and steroid-dependent plasticity of auditory frequency sensitivity in the peripheral auditory system of the midshipman fish.The potential steroid-dependent mechanism(s)that lead to this novel form of auditory and behavioral plasticity are also dis-cussed.
