Fine M L, Perini M A
Department of Biology, Virginia Commonwealth University, Richmond 23284-2012.
J Comp Physiol A. 1994 Feb;174(2):173-85. doi: 10.1007/BF00193784.
In mammals, birds and amphibians the neural pathways controlling sound production descend from higher centers in the forebrain, whereas in fishes only brainstem and spinal centers have been explicitly implicated in sound production. We now report that electrical stimulation of the forebrain of the oyster toadfish (Opsanus tau) readily evokes both the agonistic grunt and the courtship boatwhistle. Boatwhistles are more realistic than ones previously evoked from lower centers. Positive stimulation sites are localized in the preoptic area (nucleus preopticus parvocellularis anterior) and the supra-commissural nucleus of the ventral telencephalon, a likely homologue of the amygdala. Both sites contain gonadal steroid-concentrating neurons and play a central role in fish courtship behavior. Evoked sounds form a continuum from knock grunts, burst grunts, transition boatwhistles to complete boatwhistles; sound pressure level (SPL), fundamental frequency and duration increase consistently within the continuum. For all sound types, SPLs exhibit the smallest variation (coefficients of variation of 2.7 to 5.7%), fundamental frequency is intermediate (5 to 13%) and durations vary most widely (18 to 60%). Boatwhistles, with the smallest variation and greatest amplitude, are likely generated by a maximal output of the CNS and sonic muscles. Grunt SPLs however, vary over a range of 26 dB for all fish and by as much as 18 dB in an individual; suggesting recruitment of variable numbers of motor units despite electrical coupling within the sonic motor nucleus.
在哺乳动物、鸟类和两栖动物中，控制发声的神经通路从前脑的高级中枢下行，而在鱼类中，只有脑干和脊髓中枢与发声明确相关。我们现在报告，电刺激牡蛎蟾鱼（Opsanus tau）的前脑很容易诱发争斗性呼噜声和求偶船笛声。船笛声比之前从较低中枢诱发的声音更逼真。阳性刺激位点位于视前区（视前核小细胞前部）和腹侧端脑的连合上核，这可能是杏仁核的同源物。这两个位点都含有性腺类固醇浓缩神经元，并且在鱼类求偶行为中起核心作用。诱发的声音形成一个连续体，从敲击呼噜声、爆发呼噜声、过渡船笛声到完整的船笛声；声压级（SPL）、基频和持续时间在连续体内持续增加。对于所有声音类型，声压级的变化最小（变异系数为2.7%至5.7%），基频居中（5%至13%），持续时间变化最大（18%至60%）。船笛声变化最小且振幅最大，可能是由中枢神经系统和发声肌肉的最大输出产生的。然而，所有鱼类的呼噜声声压级变化范围为26分贝，个体差异高达18分贝；这表明尽管发声运动核内存在电耦合，但仍招募了数量可变的运动单位。
