Efferent System Flashcards
What are the two main divisions of the efferent system? Which one do we know more about?
The two main divisions of the efferent system, the caudal and rostral efferent system. We know more about the caudal efferent system.
What are the 3 main feedback loops in the rostral portion? Which is the main auditory processing loop?
The three main feedback loops are the reciprocal loop 1 (AC/IC/vMGB), reciprocal loop 2 (AC/IC/PTG), and reciprocal loop 3 (AC/SC/MGB). The main auditory processing loop is the reciprocal Loop 1.
The neurons in the LOCB originate from where? Do they mostly have crossed or uncrossed projections?
The neurons in the LOCB originate from the LSO and the surrounding area. They have mostly ipsilateral pathways, so uncrossed projections.
The neurons in the MOCB originate from where? Do they mostly have crossed or uncrossed projections?
The neurons of the MOCB originate from the MNTB, VNTB, DMPO, and VMPO. The neurons in the MOCB are mostly crossed.
Describe the connections of MOCB fibers to IHCs and OHCs.
The MOCB fibers connect directly to the outer hair cells, whereas the fibers are connected to the afferent connection, rather than the body of the cell.
How do rate-intensity functions change with background noise? Noise + MOCB?
With noise, there is an increase in threshold in the tuning curve. With noise and MOCB it closely approximates the tuning curve to the stimulus alone without noise.
What is the average change in threshold for an ANF with MOCB stimulation?
15 dB
How does the cochlear microphonic change with MOCB stimulation?
With MOCB stimulation, there is an increase in the cochlear microphonic at low and mid frequencies.
How does the compound action potential change with MOCB stimulation?
The compound action potential is decreased with MOCB stimulation.
How does the summating potential change with MOCB stimulation?
The summating potential is decreased with MOCB stimulation.
How does the endocochlear potential change with MOCB stimulation?
Endocochlear potential is reduced by 6-7% reduced with MOCB stimulation.
How does MOCB stimulation change hair cell polarization?
MOCB stimulation causes hyperpolarization in the hair cells. This occurs when positively charged potassium or negatively charged chloride channels are opened in the hair cell.
