What is the Olivocochlear reflex?
The olivocochlear (OC) reflex is activated by sounds, and its physiological effect is to suppress auditory nerve and cochlear responses (Buño 1978; Liberman 1989).
What is Olivocochlear bundle?
One component of the auditory efferent system, referred to as the olivocochlear bundle, projects from the superior olivary complex right back to the cochlea. The medial part of the olivocochlear bundle innervates the outer hair cells, which drive the active amplification mechanism within the cochlea.
What is the function of the Olivocochlear bundle the efferent central auditory nervous system pathway?
Background Olivocochlear (OC) neurons make up an efferent, descending auditory system that returns sound representations to the inner ear soon after they have entered the brain. Efferent inputs into the cochlea modulate outer hair cell activity to improve the neural encoding of auditory signals in background noise.
What effect does the medial olivary complex efferent feedback have?
The MOC bundle attenuates the response of the cochlea to sound by reducing the gain of the outer hair cell mechanical response to stimulation. The MOC system probably functions in a protective role by acting to reduce receptor damage during intense acoustic exposure.
What is the MOC reflex?
The basic MOC acoustic reflex. The auditory nerve responds to sound, sending a signal to the cochlear nucleus. Afferent nerve fibres cross the midline from the cochlear nucleus to the cell bodies of the MOCS (located near the MSOC), whose efferent fibres project back to the cochlea (red).
What is superior olivary nucleus?
The superior olivary nuclei are a group of nuclei located in the brainstem near the junction of the pons and medulla. It is the first auditory relay after the cochlear nucleus on the way to the auditory cortex and is the major point at which information from the two ears is integrated.
What do Stereocilia do?
Stereocilia are actin-based protrusions on auditory and vestibular sensory cells that are required for hearing and balance. They convert physical force from sound, head movement or gravity into an electrical signal, a process that is called mechanoelectrical transduction.
What is the efferent auditory system?
Researchers have defined the “efferent system” in the auditory system as centrifugal pathways that run to the inner ear hearing and balance peripheral receptors [2]. According to the findings of the further studies, the auditory. efferent system was parallel to the auditory afferent system with.
What is the Olivocochlear system?
The olivocochlear system is a component of the auditory system involved with the descending control of the cochlea.
What is meant by afferent and efferent?
Afferent neurons carry signals to the brain and spinal cord as sensory data. This neuron’s response is to send an impulse through the central nervous system. Efferent neurons are motor nerves. These are motor neurons carrying neural impulses away from the central nervous system and toward muscles to cause movement.
What is the auditory pathway?
Auditory messages are conveyed to the brain via two types of pathway: the primary auditory pathway which exclusively carries messages from the cochlea, and the non-primary pathway (also called the reticular sensory pathway) which carries all types of sensory messages.
What is the superior olivary nucleus used for?
The superior olivary nucleus consists of the lateral superior olive and medial superior olive, as well as a number of surrounding nuclei known as the periolivary nuclei. The superior olivary nuclei are thought to be involved in hearing, and specifically with identifying the location of sounds.
What happens when the olivocochlear bundle is transected?
When the olivocochlear bundle is surgically transected prior to the onset of hearing, auditory sensitivity is compromised. However, upon genetic ablation of either the alpha9 or alpha10 genes, such effects are not observed.
What is the activity of the olivocochlear system?
All currently known activity of the olivocochlear system is via a nicotinic class neurotransmitter receptor complex that is coupled with a calcium-activated potassium channel. Together, these systems generate an unusual synaptic response to stimulation from the brain.
Is the OCB part of the cochlear system?
The OCB contains fibres projecting to both the ipsilateral and contralateral cochleae, prompting an initial division into crossed (COCB) and uncrossed (UCOCB) systems. More recently, however, the division of the OCB is based on the cell bodies’ site of origin in the brainstem relative to the medial superior olive (MSO).