Schuller G
Exp Brain Res. 1979 Jan 2;34(1):117-32. doi: 10.1007/BF00238345.
Single neurons in the inferior colliculus of the Greater Horseshoe bat, Rhinolophus ferrumequinum, showed two broad categories of response patterns to sinusoidally frequency (SFM) or amplitude (SAM) modulated stimuli. Tonic responding cells (best excitatory frequency (BEF) between 10 and 90 kHz) showed a rough sinusoidal modulation of the discharge pattern to SFM. Transient responding neurons generally showing on- or off-responses to pure tones, (BEF between 65 and 88 kHz), displayed highly synchronized discharge patterns to SFM-cycles (Fig. 1). Modulation rates between 20 and 100 Hz were most effective and some neurons encoded modulation rates up to 350 Hz (Figs. 2 and 3). The SFM responses were best synchronized to the modulation envelope for center frequencies in the upper portion of the tuning curve (Figs. 4 and 5). Sharply tuned neurons with BEF around 80 kHz had the lowest threshold for modulation depth (+/- 10 Hz or 0.025%) (Fig. 6). In general, SAMs evoked the same type of response patterns and were encoded down to modulation index of 3% (Fig. 7). The fine frequency and amplitude discriminations for periodical modulations by collicular neurons is discussed as related to the detection and discrimination performance of bats, when preying on flying insects in clustered surroundings.
大马蹄蝠（Rhinolophus ferrumequinum）下丘中的单个神经元对正弦频率调制（SFM）或幅度调制（SAM）刺激表现出两大类反应模式。紧张性反应细胞（最佳兴奋频率（BEF）在10至90千赫兹之间）对SFM的放电模式呈现出大致的正弦调制。瞬态反应神经元通常对纯音表现出开或关反应（BEF在65至88千赫兹之间），对SFM周期呈现出高度同步的放电模式（图1）。20至100赫兹之间的调制率最为有效，一些神经元能够编码高达350赫兹的调制率（图2和图3）。对于调谐曲线上部中心频率的SFM反应，与调制包络的同步性最佳（图4和图5）。最佳兴奋频率约为80千赫兹的锐调谐神经元具有最低的调制深度阈值（±10赫兹或0.025%）（图6）。一般来说，SAM引发相同类型的反应模式，并且能够编码至3%的调制指数（图7）。本文讨论了下丘神经元对周期性调制的精细频率和幅度辨别，这与蝙蝠在集群环境中捕食飞行昆虫时的检测和辨别性能相关。
