02056nas a2200169 4500008004100000245016200041210006900203520138200272653002601654653003101680653002401711653002001735653003101755100002301786700002101809856005601830 2019 eng d00aFeedforward discharges couple the singing central pattern generator and ventilation central pattern generator in the cricket abdominal central nervous system0 aFeedforward discharges couple the singing central pattern genera3 a

We investigated the central nervous coordination between singing motor activity and abdominal ventilatory pumping in crickets. Fictive singing, with sensory feedback removed, was elicited by eserine-microinjection into the brain, and the motor activity underlying singing and abdominal ventilation was recorded with extracellular electrodes. During singing, expiratory abdominal muscle activity is tightly phase coupled to the chirping pattern. Occasional temporary desynchronization of the two motor patterns indicate discrete central pattern generator (CPG) networks that can operate independently. Intracellular recordings revealed a sub-threshold depolarization in phase with the ventilatory cycle in a singing-CPG interneuron, and in a ventilation-CPG interneuron an excitatory input in phase with each syllable of the chirps. Inhibitory synaptic inputs coupled to the syllables of the singing motor pattern were present in another ventilatory interneuron, which is not part of the ventilation-CPG. Our recordings suggest that the two centrally generated motor patterns are coordinated by reciprocal feedforward discharges from the singing-CPG to the ventilation-CPG and vice versa. Consequently, expiratory contraction of the abdomen usually occurs in phase with the chirps and ventilation accelerates during singing due to entrainment by the faster chirp cycle.

10aAbdominal ventilation10aCentral pattern generation10aCorollary discharge10aFictive singing10aMotor systems coordination1 aSchöneich, Stefan1 aHedwig, Berthold uhttp://link.springer.com/10.1007/s00359-019-01377-702397nas a2200181 4500008004100000022001300041245008400054210006900138260001600207300001600223490000700239520181000246100002902056700002302085700002002108700002102128856006602149 2015 eng d a0960982200aEvolution of a Communication System by Sensory Exploitation of Startle Behavior0 aEvolution of a Communication System by Sensory Exploitation of S cJan-12-2015 a3245 - 32520 v253 a

New communication signals can evolve by sensory exploitation if signaling taps into preexisting sensory biases in receivers [1 ;  2]. For mate attraction, signals are typically similar to attractive environmental cues like food [3; 4; 5 ;  6], which amplifies their attractiveness to mates, as opposed to aversive stimuli like predator cues. Female field crickets approach the low-frequency calling song of males, whereas they avoid high-frequency sounds like predatory bat calls [7]. In one group of crickets (Eneopterinae: Lebinthini), however, males produce exceptionally high-frequency calling songs in the range of bat calls [8], a surprising signal in the context of mate attraction. We found that female lebinthines, instead of approaching singing males, produce vibrational responses after male calls, and males track the source of vibrations to find females. We also demonstrate that field cricket species closely related to the Lebinthini show an acoustic startle response to high-frequency sounds that generates substrate vibrations similar to those produced by female lebinthine crickets. Therefore, the startle response is the most likely evolutionary origin of the female lebinthine vibrational signal. In field crickets, the brain receives activity from two auditory interneurons; AN1 tuned to male calling song controls positive phonotaxis, and AN2 tuned to high-frequency bat calls triggers negative phonotaxis [9 ;  10]. In lebinthine crickets, however, we found that auditory ascending neurons are only tuned to high-frequency sounds, and their tuning matches the thresholds for female vibrational signals. Our results demonstrate how sensory exploitation of anti-predator behavior can evolve into a communication system that benefits both senders and receivers.

1 aHofstede, Hannah, M. ter1 aSchöneich, Stefan1 aRobillard, Tony1 aHedwig, Berthold uhttp://linkinghub.elsevier.com/retrieve/pii/S096098221501358501893nas a2200181 4500008004100000022001300041245010200054210006900156260001600225300001800241490000700259520129300266100002101559700002101580700002301601700002101624856006601645 2016 eng d a0960982200aAuditory fovea in the ear of a duetting katydid shows male-specific adaptation to the female call0 aAuditory fovea in the ear of a duetting katydid shows malespecif cJan-12-2016 aR1222 - R12230 v263 a

Convergent evolution has led to surprising functional and mechanistic similarities between the vertebrate cochlea and some katydid ears 1 ;  2. Here we report on an ‘auditory fovea’ (Figure 1A) in the duetting katydid Ancylecha fenestrata (Tettigoniidae). The auditory fovea is a specialized inner-ear region with a disproportionate number of receptor cells tuned to a narrow frequency range, and has been described in the cochlea of some vertebrates, such as bats and mole rats 3 ;  4. In tonotopically organized ears, the location in the hearing organ of the optimal neuronal response to a tone changes gradually with the frequency of the stimulation tone. However, in the ears of A. fenestrata, the sensory cells in the auditory fovea are tuned to the dominant frequency of the female call; this area of the hearing organ is extensively expanded in males to provide an overrepresentation of this behaviorally important auditory input. Vertebrates developed an auditory fovea for improved prey or predator detection. In A. fenestrata, however, the foveal region facilitates acoustic pair finding, and the sexual dimorphism of sound-producing and hearing organs reflects the asymmetry in the mutual communication system between the sexes ( Figures 1B, S1).

1 aScherberich, Jan1 aHummel, Jennifer1 aSchöneich, Stefan1 aNowotny, Manuela uhttp://linkinghub.elsevier.com/retrieve/pii/S0960982216312611