Meeting Abstract

P2.5  Monday, Jan. 5  The Effect of Anomalous Pulse Timing on Call Discrimination by Females of the Gray Treefrog: Behavioral Correlates of Neurobiology SCHWARTZ, Joshua/J; Pace University jschwartz2@pace.edu

Recent research has demonstrated that neurons in the auditory midbrain of anuran amphibians ‘count’ interpulse intervals (IPIs). The integration time of such neurons can differ so that some neurons fire after exposure to fewer and some to greater numbers of intervals. Moreover, the counting process can be reset to zero if an IPI falls outside the tolerance range of the cell. Other midbrain neurons respond with short-latencies and fire phasically following individual IPIs of appropriate duration. Here we tested female gray treefrogs for behavioral correlates of two neural models suggested by these neural response patterns using phonotaxis tests. The models are also relevant to understanding the mechanistic bases of known female responses to calls. For example, females often prefer longer pulsed advertisement calls to shorter calls, even when the former are presented 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 that emphasize the importance of IPIs rather than pulses, per se. Females discriminated in favor of calls with normal interpulse timing relative to those in which a single IPI was too long or too short. Although many results were consistent with neural models based on the characteristics of both classes of neurons, our data indicate a somewhat stronger contribution to female behavior by putative long-latency resettable units that count.