Journal
JOURNAL OF NEUROSCIENCE
Volume 28, Issue 25, Pages 6430-6438Publisher
SOC NEUROSCIENCE
DOI: 10.1523/JNEUROSCI.0470-08.2008
Keywords
adaptation; auditory neuron; time course; sound level; rate level function; inferior colliculus
Categories
Funding
- Medical Research Council [G0300417] Funding Source: researchfish
- Medical Research Council [G0300417] Funding Source: Medline
- MRC [G0300417] Funding Source: UKRI
Ask authors/readers for more resources
Auditory neurons must represent accurately a wide range of sound levels using firing rates that vary over a far narrower range of levels. Recently, we demonstrated that this dynamic range problem is lessened by neural adaptation, whereby neurons adjust their input output functions for sound level according to the prevailing distribution of levels. These adjustments in input-output functions increase the accuracy with which levels around those occurring most commonly are coded by the neural population. Here, we examine how quickly this adaptation occurs. We recorded from single neurons in the auditory midbrain during a stimulus that switched repeatedly between two distributions of sound levels differing in mean level. The high-resolution analysis afforded by this stimulus showed that a prominent component of the adaptation occurs rapidly, with an average time constant across neurons of 160 ms after an increase in mean level, much faster than our previous experiments were able to assess. This time course appears to be independent of both the timescale over which sound levels varied and that over which sound level distributions varied, but is related to neural characteristic frequency. We find that adaptation to an increase in mean level occurs more rapidly than to a decrease. Finally, we observe an additional, slow adaptation in some neurons, which occurs over a timescale of tens of seconds. Our findings provide constraints in the search for mechanisms underlying adaptation to sound level. They also have functional implications for the role of adaptation in the representation of natural sounds.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available