ISSN:
1432-1351
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary The cochlear response of the bat,Eptesicus pumilis, contains both positive and negative summating potentials. The intensity functions for the bat are similar in shape to those for the guinea pig except they are displaced toward higher frequencies. The bat SP is usually positive below 10 kHz and under 100 dB (Fig. 1). As the frequency is raised above 10 kHz the SP becomes negative at high intensities. Above 50 kHz the response is negative at all intensities. Responses were recorded up to 98.5 kHz in the bat and to 43.3 kHz in the guinea pig. The frequency response curve for the guinea pig SP has a peak at 10 kHz. The bat curve has two peaks, one at 25–30 kHz and one at 50–70 kHz with a 20 dB dip between (Fig. 11). Although the results were more clear-cut in the bat, SP− in both the bat (Fig. 4) and the guinea pig (Figs. 5, 9) decreased linearly during hypothermia. On occasion the SP− became positive in polarity. SP+ increased in positivity in the bat, but did not show a consistent change in the guinea pig. In the guinea pig, there was a delay in time between the decrease in body and neck musculature temperature and the decrease in SP− (Fig. 7). Changes in blood pressure during cooling of the guinea pig body did not correlate with changes in SP.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00695922
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