Brudzynski S M
Department of Psychology, Brock University, 500 Glenridge Avenue, L2S 3A1, St Catharines, Ont., Canada.
Neurosci Biobehav Rev. 2001 Dec;25(7-8):611-7. doi: 10.1016/s0149-7634(01)00058-6.
The present review is focused on the neural mechanisms and acoustic features of 22kHz alarm calls emitted by adult rats as a defensive measure in numerous behavioral situations. The alarm calls are initiated by activity of the cholinergic neurons of the laterodorsal tegmental nucleus (LDT) and a subsequent release of acetylcholine at the target areas, collectively termed as the medial cholinoceptive vocalization strip. Injection of carbachol, a predominantly muscarinic agent, into any portion of the cholinoceptive strip, or direct stimulation of the LDT, induced species-typical 22kHz calls comparable to those emitted in natural situations. The pharmacologically induced 22kHz calls contained their alarming properties for naïve rats. The 22kHz calls induced either by carbachol or by stimulation of the LDT could be antagonized by atropine, or scopolamine applied into the cholinoceptive strip. Our recent behavioral studies have shown that the combination of long call duration and constant sound frequency (20-30kHz) convey the alarming message. Anatomical and neurochemical organization of the vocalization strip and acoustic properties of the calls lead to the conclusion that 22kHz calls indicate a fundamental, negative affective state common for many behavioral situations.
本综述聚焦于成年大鼠发出的22kHz警报叫声的神经机制和声学特征，这些叫声是大鼠在多种行为情境下的一种防御手段。警报叫声由外侧背盖核（LDT）的胆碱能神经元活动引发，随后乙酰胆碱在目标区域释放，这些目标区域统称为内侧胆碱能感受性发声带。向胆碱能感受带的任何部位注射卡巴胆碱（一种主要作用于毒蕈碱的药物），或直接刺激LDT，都会诱发与自然情境中发出的类似的典型22kHz叫声。药物诱导的22kHz叫声对未接触过此类声音的大鼠具有警报特性。由卡巴胆碱或LDT刺激诱导的22kHz叫声可被注入胆碱能感受带的阿托品或东莨菪碱所拮抗。我们最近的行为研究表明，长叫声持续时间和恒定声频（20 - 30kHz）的组合传达了警报信息。发声带的解剖学和神经化学组织以及叫声的声学特性得出结论：22kHz叫声表明了许多行为情境中常见的一种基本的负面情绪状态。
