UI  - 97160053
AU  - Finlayson PG
AU  - Adam TJ
TI  - Excitatory and inhibitory response adaptation in the superior olive
      complex affects binaural acoustic processing.
LA  - Eng
MH  - Acoustic Stimulation
MH  - *Adaptation, Physiological
MH  - Animal
MH  - Auditory Perception/*physiology
MH  - Cochlear Nucleus/physiology
MH  - Comparative Study
MH  - Electrodes
MH  - Electrophysiology
MH  - Evoked Potentials, Auditory
MH  - Neurons/physiology
MH  - Olivary Nucleus/anatomy & histology/*physiology
MH  - Rats
MH  - Sound Localization/physiology
MH  - Support, Non-U.S. Gov't
PT  - JOURNAL ARTICLE
DA  - 19970417
DP  - 1997 Jan
IS  - 0378-5955
TA  - Hear Res
PG  - 1-18
SB  - M
CY  - NETHERLANDS
IP  - 1-2
VI  - 103
JC  - HCK
AA  - Author
EM  - 199706
AB  - Short-term adaptation was examined in single unit recordings from 113
      superior olive neurons of anaesthetized 3- to 6-month-old Long-Evans
      rats. Responses to an equal intensity BF probe tone presented 1 ms
      after an 'adapting' BF tone were adapted by 56.3 +/- 2.6% (mean +/-
      S.E.) compared to responses at a 512 ms delay. The rapid decrease in
      discharge rate during adapting tones often approximated exponential
      time courses with time constants of less than 20 ms. The recovery from
      adaptation was exponential with time constants of 106 +/- 20.0 ms. The
      magnitude of adaptation and time course of recovery following monaural
      stimulation of binaurally excited (EE) neurons were not significantly
      different in both input pathways. Additionally, in 60% of EE neurons,
      an 'adapting' tone presented to one ear reduced subsequent responses to
      probe tones presented to the opposite ear. Binaural stimulation
      resulted in equal or greater adaptation of responses than monaural
      stimulation of either ear. The recovery of binaural excitatory
      responses generally followed a time course between recovery functions
      for ipsilateral and contralateral monaural stimuli. Lateral Superior
      Olive (LSO) neurons encode sound source location through the
      interaction of ipsilateral excitation and contralateral inhibition
      (IE). Ipsilaterally driven excitatory responses in LSO neurons
      exhibited the greatest magnitude of adaptation (68.5 +/- 21.1%).
      Adaptation of inhibition was observed in over half of IE neurons.
      Responses of LSO neurons to binaural BF probe stimuli were greatest
      immediately after a 200 ms BF 'inhibitory adapting' stimulus to the
      contralateral ear, and decreased with greater interstimulus delays.
      Responses to binaural stimulation were constant after prior binaural
      adaptation, when the magnitude and recovery of adaptation to monaural
      stimuli were similar for excitation and inhibition (8/25 IE cells). The
      functional significance and possible sites of adaptation processes are
      discussed.
AD  - Department of Surgery, (Otolaryngology), University of British
      Columbia, Vancouver, Canada. rothearc@unixg.ubc.ca
PMID- 0009007569
SO  - Hear Res 1997 Jan;103(1-2):1-18

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