Department of Biology and Health Sciences, Pace University, Pleasantville, NY 10570, USA.
J Exp Biol. 2010 Jun 15;213(Pt 12):2066-72. doi: 10.1242/jeb.043372.
Research has demonstrated that certain midbrain neurons of anurans 'count' interpulse intervals (IPIs). Some neurons fire after exposure to fewer intervals than do others. Counting can be reset to zero if an IPI falls outside the cell's tolerance range. We tested female gray treefrogs for behavioral correlates of these neural response patterns using phonotaxis tests in order to gain a better understanding of the mechanistic bases of female responses to calls. For example, previous work demonstrated females often prefer longer to shorter pulsed advertisement calls, even when the former occur at lower rates. Call attractiveness can also be reduced when pulse duration and timing have been manipulated experimentally or disrupted by acoustic interference. In this study, female responses were consistent with neural data, emphasizing the importance of IPIs. Females discriminated in favor of calls with normal interpulse timing relative to those in which a single IPI was too long or too short. Our data suggest that neural resetting of interval counting by inappropriate intervals may more strongly influence females than reduced firing in response to such intervals on an individual basis. Data also suggest a transition point between 125 ms and 175 ms at which an interval between pulse strings is treated as an interval between calls.
研究表明，某些无尾两栖类动物的中脑神经元可以“计算”脉冲间隔（IPI）。与其他神经元相比，一些神经元在暴露于较少的间隔后会发出信号。如果 IPI 超出细胞的容忍范围，则可以将计数重置为零。为了更好地了解雌性对叫声反应的机制基础，我们使用声定向测试对雌性灰色树蛙进行了这些神经反应模式的行为相关性测试。例如，之前的研究表明，即使前者的发生频率较低，雌性通常也更喜欢长脉冲广告叫声而不是短脉冲广告叫声。当脉冲持续时间和定时通过实验操纵或受到声干扰而中断时，叫声吸引力也会降低。在这项研究中，女性的反应与神经数据一致，强调了 IPI 的重要性。与单个 IPI 过长或过短的叫声相比，女性更倾向于具有正常脉冲定时的叫声。我们的数据表明，不适当的间隔引起的间隔计数重置可能比个体对这种间隔的反应性降低对雌性的影响更大。数据还表明，在 125 毫秒和 175 毫秒之间存在一个转折点，在此期间，脉冲串之间的间隔被视为呼叫之间的间隔。
