Bushy cells are two types of second order neuron found in the anterior part of the
ventral cochlear nucleus
In the ventral cochlear nucleus (VCN), auditory nerve fibers enter the brain via the nerve root in the VCN. The ventral cochlear nucleus is divided into the anterior ventral (anteroventral) cochlear nucleus (AVCN) and the posterior ventral (poster ...
, the AVCN. They can be ''globular'' or ''spherical'' giving outputs to different parts of the
superior olivary complex
The superior olivary complex (SOC) or superior olive is a collection of brainstem nuclei that functions in multiple aspects of hearing and is an important component of the ascending and descending auditory pathways of the auditory system. The SO ...
.
Structure
Bushy cells are named after their appearance to
bushes
A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...
, having short dendrites. They are almost completely engulfed by the synaptic connections from the
endbulbs of Held.
Function
Because of the large synaptic contact from the
auditory nerve
The cochlear nerve (also auditory nerve or acoustic nerve) is one of two parts of the vestibulocochlear nerve, a cranial nerve present in amniotes, the other part being the vestibular nerve. The cochlear nerve carries auditory sensory information ...
fibres, the output pattern from the bushy cell is almost the same as the auditory nerve input. Projections from the globular bushy cells extend to the
superior olive
The superior olivary complex (SOC) or superior olive is a collection of brainstem nuclei that functions in multiple aspects of hearing and is an important component of the ascending and descending auditory pathways of the auditory system. The SO ...
on both sides of the
brainstem
The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is ...
where they give input to the bipolar neurons. The superior olive is an area seen to be of importance in the processing of binaural signals.
[
Projections from the spherical bushy cells give excitatory input to the lateral and medial parts of the superior olive (the LSO and MSO). Again their very close synaptic coupling suggest a part in the role of processing ]interaural time difference
The interaural time difference (or ITD) when concerning humans or animals, is the difference in arrival time of a sound between two ears. It is important in the localization of sounds, as it provides a cue to the direction or angle of the sound s ...
s,[ while their connection to the LSO suggests that fast timing is also important in processing ]interaural level difference
Sound localization is a listener's ability to identify the location or origin of a detected sound in direction and distance.
The sound localization mechanisms of the mammalian auditory system have been extensively studied. The auditory system us ...
.
References
{{reflist
External links
Google book
Neurons