Minimal Number of Required Inputs for Temporally Precise Action Potential Generation in Auditory Brainstem Nuclei

The auditory system relies on temporal precise information transfer, requiring an interplay of synchronously activated inputs and rapid postsynaptic integration. During late postnatal developmental synaptic, biophysical, and morphological features change to enable matured auditory neurons to perform...

Full description

Saved in:
Bibliographic Details
Published in:Frontiers in cellular neuroscience 2020-11, Vol.14, p.592213-592213
Main Authors: Kladisios, Nikolaos, Fischer, Linda, Felmy, Felix
Format: Article
Language:English
Subjects:
Action potential
action potential generation
auditory brainstem
Auditory system
Brain stem
Cellular Neuroscience
Electrophysiology
Excitatory postsynaptic potentials
Hearing
Integration
lateral lemniscus
Lemniscus (lateral)
Morphology
Neurons
postnatal development
superior olive
synaptic transmission
Trapezoid body
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The auditory system relies on temporal precise information transfer, requiring an interplay of synchronously activated inputs and rapid postsynaptic integration. During late postnatal developmental synaptic, biophysical, and morphological features change to enable matured auditory neurons to perform their appropriate function. How the number of minimal required input fibers and the relevant EPSC time course integrated for action potential generation changes during late postnatal development is unclear. To answer these questions we used in vitro electrophysiology in auditory brainstem structures from pre-hearing onset and mature Mongolian gerbils of either sex. Synaptic and biophysical parameters changed distinctively during development in the medial nucleus of the trapezoid body (MNTB), the medial superior olive (MSO), and the ventral and dorsal nucleus of the lateral lemniscus (VNLL and DNLL). Despite a reduction in input resistance in most cell types, all required fewer inputs in the mature stage to drive action potentials. Moreover, the EPSC decay time constant is a good predictor of the EPSC time used for action potential generation in all nuclei but the VNLL. Only in MSO neurons, the full EPSC time course is integrated by the neuron’s resistive element, while otherwise the relevant EPSC time matches only 5-10 % of the membrane time constant, indicating its dominant role for membrane charging. We conclude, that distinct developmental programs lead to a general increase in temporal precision and integration accuracy matched to the information relaying properties of auditory nuclei.
ISSN:1662-5102
1662-5102
DOI:10.3389/fncel.2020.592213