Short-term plasticity and auditory processing in the ventral cochlear nucleus of normal and hearing-impaired animals

Division of Otolaryngology and Neuroscience Program, 3C120 School of Medicine, 30 North, 1900 East, Salt Lake City, University of Utah, UT 84132, USA.
Hearing research (Impact Factor: 2.97). 05/2011; 279(1-2):131-9. DOI: 10.1016/j.heares.2011.04.018
Source: PubMed


The dynamics of synaptic transmission between neurons plays a major role in neural information processing. In the cochlear nucleus, auditory nerve synapses have a relatively high release probability and show pronounced synaptic depression that, in conjunction with the variability of interspike intervals, shapes the information transmitted to the postsynaptic cells. Cellular mechanisms have been best analyzed at the endbulb synapses, revealing that the recent history of presynaptic activity plays a complex, non-linear, role in regulating release. Emerging evidence suggests that the dynamics of synaptic function differs according to the target neuron within the cochlear nucleus. One consequence of hearing loss is changes in evoked release at surviving auditory nerve synapses, and in some situations spontaneous release is greatly enhanced. In contrast, even with cochlear ablation, postsynaptic excitability is less affected. The existing evidence suggests that different modes of hearing loss can result in different dynamic patterns of synaptic transmission between the auditory nerve and postsynaptic neurons. These changes in dynamics in turn will affect the efficacy with which different kinds of information about the acoustic environment can be processed by the parallel pathways in the cochlear nucleus.

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    • "Short-term depression (STD) in a brief time window of <1 s has been described at specialized terminals of auditory nerve fibers, the endbulbs of Held, which contact bushy cells in the cochlear nuclear complex. Here, STD occurs upon stimulation with 100–300 Hz over a period of 150 ms (Oleskevich and Walmsley, 2002; Wang and Manis, 2006, 2008; Wang et al., 2010, 2011). STD was also reported in GABAergic synapses between the inferior colliculus and the medial geniculate body (Venkataraman and Bartlett, 2013). "
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