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Hair Cell and Meddis Hair Cell Model. Xiaoxiang Gong. Outline. Function of Hair Cells Hair Cell Model – Meddis Model Simulation Result for the Meddis Model Phase Locking. Function of Hair Cell. Meddis Model for Hair Cell. Synaptic cleft Outside the Hair cell. Hair cell.
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Hair Cell and Meddis Hair Cell Model Xiaoxiang Gong
Outline • Function of Hair Cells • Hair Cell Model – Meddis Model • Simulation Result for the Meddis Model • Phase Locking
Meddis Model for Hair Cell Synaptic cleft Outside the Hair cell Hair cell • Spike Probability is proportional to the amount of transmitter in the synaptic cleft.
Simulation Result for Meddis Model -- from Auditory Toolbox • Stimulus: Single tone (1KHz) with amplitude scales on silent background. • Spontaneous rate • Onset rate: the initial peak value • Steady state rate: adaptation level
Phase Locking • The auditory nerve will tend to fire at a particular phase of a stimulating low-frequency tone (Period Histogram). So the inter-spike intervals tend to occur at integer multiples of the periods of the tone (Inter-spike Interval Histogram). • Phase locking depends on the stimulus frequency: with high frequency tones (> 3kHz) phase locking gets weaker.
Phase Locking-- Period Histogram & Inter-spike Interval Histogram AN fibers fire at integer multiples of the stimulus period, not necessarily on every period
Phase Locking-- Period Histograms from Meddis Model • Showing a half-wave rectified version of the stimulus
Phase Locking-- Inter-spike Interval Histograms from Meddis Model • AN fibers fire at intervals related to stimulus frequency. For 1KHz sinusoid input