کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9436647 | 1615695 | 2005 | 15 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Corticofugal modulation of directional sensitivity in the midbrain of the big brown bat, Eptesicus fuscus
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کلمات کلیدی
BATSPLPSTBAZcorticofugal modulationPps - PPSInhibition - بازداریFrequency - بسامد یا فرکانسbest frequency - بهترین فرکانسminimum threshold - حداقل آستانهdirectional sensitivity - حساسیت جهتSound pressure level - سطح فشار صوتAuditory Cortex - قشر شنواییpulses per second - پالس در ثانیهInferior colliculus - کولیکولوس پایین
موضوعات مرتبط
علوم زیستی و بیوفناوری
علم عصب شناسی
سیستم های حسی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
In our recent study of corticofugal modulation of collicular amplitude sensitivity of the big brown bat, Eptesicus fuscus, we suggested that the corticofugal modulation is based upon the best frequency (BF) differences and the relative amplitude sensitivity difference between collicular (IC) and cortical (AC) neurons but not the absolute amplitude sensitivity of IC and AC neurons. To show that corticofugal modulation is systematic and multiparametric, we studied corticofugal modulation of directional sensitivity in 89 corticofugally inhibited IC neurons in the same bat species under free field stimulation conditions. A neuron's directional sensitivity was expressed with the azimuthal range (AR) at 50% below the maximum of each directional sensitivity curve and the best azimuth (BAZ) at which the neuron discharged maximally. Cortical electrical stimulation did not affect the directional sensitivity of 40 (45%) neurons with BFIC-AC differences of 7.3 ± 4.4 kHz but sharpened the directional sensitivity of other 49 (55%) neurons with BFIC-AC differences of 2.3 ± 1.8 kHz. Corticofugal modulation sharpened directional sensitivity curves of IC neurons by decreasing the AR and shifting collicular BAZ toward cortical BAZ. The decrease in AR and the shift in BAZ increased significantly with ARIC-AC and BAZIC-AC differences but not with absolute AR and BAZ of IC and AC neurons or BFIC-AC differences. Corticofual modulation also shifted collicular BF toward cortical BF. The shift in BF increased significantly with BFIC-AC differences but not with the BF of IC and AC neurons or BAZ shift. Consonant with our previous study, these data indicate that corticofugal modulation of collicular directional sensitivity is based on topographic projections between the IC and the AC and the difference in directional sensitivity but not the absolute directional sensitivity of IC or AC neurons.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Hearing Research - Volume 203, Issues 1â2, May 2005, Pages 201-215
Journal: Hearing Research - Volume 203, Issues 1â2, May 2005, Pages 201-215
نویسندگان
Xiaoming Zhou, Philip H.-S. Jen,