Pillat J, Schuller G
Zoologisches Institut der Ludwig-Maximilians-Universität, Munich, Germany.
Exp Brain Res. 1998 Mar;119(1):17-26. doi: 10.1007/s002210050315.
The role of the paralemniscal tegmental area of the horseshoe bat, Rhinolophus rouxi, in the control of vocalization and Doppler-shift compensation was investigated using electrical and pharmacological stimulation and lesioning techniques. The paralemniscal tegmental area is situated in the dorsolateral tegmentum ventral to the inferior colliculus and rostral and medial to the dorsal and intermediate nuclei of the lateral lemniscus. Vocalizations indistinguishable from spontaneously uttered calls can be elicited with both electrical and pharmacological stimulation methods, demonstrating that the stimulation of neural elements within the area and not fibers passing through the area are responsible for the stimulated call emission. The audiovocal feedback system for Doppler-shift compensation was also investigated. Doppler-shift compensation adjusts the frequency of the emitted calls according to the increases in the frequency of the echoes that are normally encountered in flying bats. Bats compensate for Doppler shifts not only under natural conditions but also when echoes are played back to the bat following spontaneous vocalizations or vocalizations induced by electrical or pharmacological stimulation of the investigated brain area. Unilateral electrolytic lesions of the paralemniscal tegmental area did not impair the ability to evoke vocalizations with electrical stimulation of the unlesioned side. The calls had exactly the same structure and frequency composition as those emitted prior to lesioning. Unilateral lesions also did not impair Doppler-shift compensation performance. After bilateral lesioning of the paralemniscal area, vocalizations could not be evoked with electrical stimulation. However, normal calls were emitted spontaneously and Doppler-shift compensation during spontaneous call emission was unaltered compared with the intact condition. The paralemniscal tegmental area is therefore not an audiovocal feedback system required for Doppler-shift compensation, but rather a brain area whose stimulation and activation is sufficient but not necessary for call emission. It is also not directly involved in the control of spectral parameters of vocalization but contributes to the control of the occurrence of vocal output.
利用电刺激、药物刺激和损伤技术，研究了鲁氏菊头蝠马蹄叶旁被盖区在发声控制和多普勒频移补偿中的作用。马蹄叶旁被盖区位于下丘下方的背外侧被盖，外侧丘系背核和中间核的嘴侧和内侧。电刺激和药物刺激方法均可引发与自发叫声难以区分的发声，这表明该区域内神经元的刺激而非穿过该区域的纤维负责引发受刺激的叫声。还研究了用于多普勒频移补偿的听觉-发声反馈系统。多普勒频移补偿根据飞行蝙蝠通常遇到的回声频率增加来调整发出叫声的频率。蝙蝠不仅在自然条件下，而且在自发发声或对所研究脑区进行电刺激或药物刺激诱发发声后向其回放回声时，都能补偿多普勒频移。马蹄叶旁被盖区的单侧电解损伤并不损害用电刺激未损伤侧诱发发声的能力。发出的叫声在结构和频率组成上与损伤前发出的叫声完全相同。单侧损伤也不损害多普勒频移补偿性能。马蹄叶旁被盖区双侧损伤后，电刺激无法诱发发声。然而，仍能自发发出正常叫声，且自发发声时的多普勒频移补偿与完整状态相比未发生改变。因此，马蹄叶旁被盖区不是多普勒频移补偿所需的听觉-发声反馈系统，而是一个其刺激和激活足以但并非引发叫声所必需的脑区。它也不直接参与发声频谱参数的控制，但有助于控制发声输出的发生。
