Figure 9.

Tonotopic compression of low frequencies in MSO. A, B, The dorsoventral location, normalized to the dorsoventral extent of the MSO, is shown for all endpoints of all reconstructed fibers on a logarithmic CF abscissa (A) and for their mean and SD on a cochlear distance abscissa (B). Each circle in A indicates a single endpoint (blue, contralateral fiber; red, ipsilateral fiber). The asterisks and the black circles and line show extracellular and summary data from Guinan et al. (1972) (see main text). The green lines are predicted relationships based on the cochlear tonotopic map, based on Greenwood's formula (Greenwood, 1990). The solid green line is the prediction for a full representation of all CFs; the dashed line is for a representation limited to ≤22 kHz. The endpoints at low CFs cluster above the green lines. If low CFs were over-represented in MSO, those endpoints would be expected to cluster below rather than above the green lines.