TY - JOUR A1 - Korniienko, Yevheniia A1 - Nguyen, Linh A1 - Baumgartner, Stephanie A1 - Vater, Marianne A1 - Tiedemann, Ralph A1 - Kirschbaum, Frank T1 - Correction to: Intragenus F1-hybrids of African weakly electric fish (Mormyridae: Campylomormyrus tamandua male x C. compressirostris female) are fertile (vol 206, pg 571, 2020) JF - Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology Y1 - 2021 U6 - https://doi.org/10.1007/s00359-021-01513-2 SN - 0340-7594 SN - 1432-1351 VL - 207 IS - 6 SP - 773 EP - 773 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Korniienko, Yevheniia A1 - Tiedemann, Ralph A1 - Vater, Marianne A1 - Kirschbaum, Frank T1 - Ontogeny of the electric organ discharge and of the papillae of the electrocytes in the weakly electric fish Campylomormyrus rhynchophorus (Teleostei: Mormyridae) JF - The journal of comparative neurology N2 - The electric organ of the mormyrid weakly electric fish,Campylomormyrus rhynchophorus(Boulenger, 1898), undergoes changes in both the electric organ discharge (EOD) and the light and electron microscopic morphology as the fish mature from the juvenile to the adult form. Of particular interest was the appearance of papillae, surface specializations of the uninnervated anterior face of the electrocyte, which have been hypothesized to increase the duration of the EOD. In a 24.5 mm long juvenile the adult electric organ (EO) was not yet functional, and the electrocytes lacked papillae. A 40 mm long juvenile, which produced a short biphasic EOD of 1.3 ms duration, shows small papillae (average area 136 mu m(2)). In contrast, the EOD of a 79 mm long juvenile was triphasic. The large increase in duration of the EOD to 23.2 ms was accompanied by a small change in size of the papillae (average area 159 mu m(2)). Similarly, a 150 mm long adult produced a triphasic EOD of comparable duration to the younger stage (24.7 ms) but featured a prominent increase in size of the papillae (average area 402 mu m(2)). Thus, there was no linear correlation between EOD duration and papillary size. The most prominent ultrastructural change was at the level of the myofilaments, which regularly extended into the papillae, only in the oldest specimen-probably serving a supporting function. Physiological mechanisms, like gene expression levels, as demonstrated in someCampylomormyrusspecies, might be more important concerning the duration of the EOD. KW - Campylomormyrus KW - electric organ discharge KW - electrocyte ontogeny KW - electrocyte ultrastructure KW - papillae Y1 - 2020 U6 - https://doi.org/10.1002/cne.25003 SN - 0021-9967 SN - 1096-9861 VL - 529 IS - 5 SP - 1052 EP - 1065 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Nguyen, Manh Duy Linh A1 - Mamonekene, Victor A1 - Vater, Marianne A1 - Bartsch, Peter A1 - Tiedemann, Ralph A1 - Kirschbaum, Frank T1 - Ontogeny of electric organ and electric organ discharge in Campylomormyrus rhynchophorus (Teleostei: Mormyridae) JF - Journal of comparative physiology; A, Neuroethology, sensory, neural, and behavioral physiology N2 - The aim of this study was a longitudinal description of the ontogeny of the adult electric organ of Campylomormyrus rhynchophorus which produces as adult an electric organ discharge of very long duration (ca. 25 ms). We could indeed show (for the first time in a mormyrid fish) that the electric organ discharge which is first produced early during ontogeny in 33-mm-long juveniles is much shorter in duration and has a different shape than the electric organ discharge in 15-cm-long adults. The change from this juvenile electric organ discharges into the adult electric organ discharge takes at least a year. The increase in electric organ discharge duration could be causally linked to the development of surface evaginations, papillae, at the rostral face of the electrocyte which are recognizable for the first time in 65-mm-long juveniles and are most prominent at the periphery of the electrocyte. KW - Weakly electric fish KW - Development KW - Electric organ discharge KW - Electric KW - organ KW - Electrocyte features Y1 - 2020 U6 - https://doi.org/10.1007/s00359-020-01411-z SN - 0340-7594 SN - 1432-1351 VL - 206 IS - 3 SP - 453 EP - 466 PB - Springer CY - Berlin ; Heidelberg ER - TY - JOUR A1 - Korniienko, Yevheniia A1 - Nguyen, Linh A1 - Baumgartner, Stephanie A1 - Vater, Marianne A1 - Tiedemann, Ralph A1 - Kirschbaum, Frank T1 - Intragenus F1-hybrids of African weakly electric fish (Mormyridae: Campylomormyrus tamandua male x C. compressirostris female) are fertile JF - Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology N2 - Hybridization is widespread in fish and constitutes an important mechanism in fish speciation. There is, however, little knowledge about hybridization in mormyrids. F1-interspecies hybrids betweenCampylomormyrus tamandua male x C. compressirostris female were investigated concerning: (1) fertility; (2) survival of F2-fish and (3) new gene combinations in the F2-generation concerning the structure of the electric organ and features of the electric organ discharge. These F1-hybrids achieved sexual maturity at about 12-13.5 cm total length. A breeding group comprising six males and 13 females spawned 28 times naturally proving these F1-fish to be fertile. On average 228 eggs were spawned, the average fertilization rate was 47.8%. Eggs started to hatch 70-72 h after fertilization, average hatching rate was 95.6%. Average mortality rate during embryonic development amounted to 2.3%. Average malformation rate during the free embryonic stage was 27.7%. Exogenous feeding started on day 11. In total, we raised 353 normally developed larvae all of which died consecutively, the oldest specimen reaching an age of 5 months. During survival, the activities of the larval and adult electric organs were recorded and the structure of the adult electric organ was investigated histologically. KW - mormyridae KW - campylomormyrus KW - F1-hybrids KW - F2-hybrids KW - fertility Y1 - 2020 U6 - https://doi.org/10.1007/s00359-020-01425-7 SN - 0340-7594 SN - 1432-1351 VL - 206 IS - 4 SP - 571 EP - 585 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Paul, Christiane A1 - Mamonekene, Victor A1 - Vater, Marianne A1 - Feulner, Philine G. D. A1 - Engelmann, Jacob A1 - Tiedemann, Ralph A1 - Kirschbaum, Frank T1 - Comparative histology of the adult electric organ among four species of the genus Campylomormyrus (Teleostei: Mormyridae) JF - Journal of comparative physiology : A, Neuroethology, sensory, neural, and behavioral physiology N2 - The electric organ (EO) of weakly electric mormyrids consists of flat, disk-shaped electrocytes with distinct anterior and posterior faces. There are multiple species-characteristic patterns in the geometry of the electrocytes and their innervation. To further correlate electric organ discharge (EOD) with EO anatomy, we examined four species of the mormyrid genus Campylomormyrus possessing clearly distinct EODs. In C. compressirostris, C. numenius, and C. tshokwe, all of which display biphasic EODs, the posterior face of the electrocytes forms evaginations merging to a stalk system receiving the innervation. In C. tamandua that emits a triphasic EOD, the small stalks of the electrocyte penetrate the electrocyte anteriorly before merging on the anterior side to receive the innervation. Additional differences in electrocyte anatomy among the former three species with the same EO geometry could be associated with further characteristics of their EODs. Furthermore, in C. numenius, ontogenetic changes in EO anatomy correlate with profound changes in the EOD. In the juvenile the anterior face of the electrocyte is smooth, whereas in the adult it exhibits pronounced surface foldings. This anatomical difference, together with disparities in the degree of stalk furcation, probably contributes to the about 12 times longer EOD in the adult. KW - Mormyridae KW - Campylomormyrus KW - Electric organ discharge KW - Electrocyte geometry KW - Electric organ ontogeny Y1 - 2015 U6 - https://doi.org/10.1007/s00359-015-0995-6 SN - 0340-7594 SN - 1432-1351 VL - 201 IS - 4 SP - 357 EP - 374 PB - Springer CY - New York ER - TY - JOUR A1 - Kössl, Manfred A1 - Hechavarria, Julio A1 - Voss, Cornelia A1 - Schaefer, Markus A1 - Vater, Marianne T1 - Bat auditory cortex - model for general mammalian auditory computation or special design solution for active time perception? JF - European journal of neuroscience N2 - Audition in bats serves passive orientation, alerting functions and communication as it does in other vertebrates. In addition, bats have evolved echolocation for orientation and prey detection and capture. This put a selective pressure on the auditory system in regard to echolocation-relevant temporal computation and frequency analysis. The present review attempts to evaluate in which respect the processing modules of bat auditory cortex (AC) are a model for typical mammalian AC function or are designed for echolocation-unique purposes. We conclude that, while cortical area arrangement and cortical frequency processing does not deviate greatly from that of other mammals, the echo delay time-sensitive dorsal cortex regions contain special designs for very powerful time perception. Different bat species have either a unique chronotopic cortex topography or a distributed salt-and-pepper representation of echo delay. The two designs seem to enable similar behavioural performance. KW - chronotopy KW - echolocation KW - fovea KW - salt-and-pepper KW - target range Y1 - 2015 U6 - https://doi.org/10.1111/ejn.12801 SN - 0953-816X SN - 1460-9568 VL - 41 IS - 5 SP - 518 EP - 532 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Koessl, M. A1 - Hechavarria, J. C. A1 - Voss, C. A1 - Macias, S. A1 - Mora, E. C. A1 - Vater, Marianne T1 - Neural maps for target range in the auditory cortex of echolocating bats JF - Current opinion in neurobiology : reviews of all advances ; evaluation of key references ; comprehensive listing of papers N2 - Computational brain maps as opposed to maps of receptor surfaces strongly reflect functional neuronal design principles. In echolocating bats, computational maps are established that topographically represent the distance of objects. These target range maps are derived from the temporal delay between emitted call and returning echo and constitute a regular representation of time (chronotopy). Basic features of these maps are innate, and in different bat species the map size and precision varies. An inherent advantage of target range maps is the implementation of mechanisms for lateral inhibition and excitatory feedback. Both can help to focus target ranging depending on the actual echolocation situation. However, these maps are not absolutely necessary for bat echolocation since there are bat species without cortical target-distance maps, which use alternative ensemble computation mechanisms. Y1 - 2014 U6 - https://doi.org/10.1016/j.conb.2013.08.016 SN - 0959-4388 SN - 1873-6882 VL - 24 SP - 68 EP - 75 PB - Elsevier CY - London ER - TY - JOUR A1 - Hechavarria, Julio C. A1 - Macias, Silvio A1 - Vater, Marianne A1 - Mora, Emanuel C. A1 - Kössl, Manfred T1 - Evolution of neuronal mechanisms for echolocation specializations for target-range computation in bats of the genus Pteronotus JF - The journal of the Acoustical Society of America N2 - Delay tuning was studied in the auditory cortex of Pteronotus quadridens. All the 136 delay-tuned units that were studied responded strongly to heteroharmonic pulse-echo pairs presented at specific delays. In the heteroharmonic pairs, the first sonar call harmonic marks the timing of pulse emission while one of the higher harmonics (second or third) indicates the timing of the echo. Delay-tuned units are organized chronotopically along a rostrocaudal axis according to their characteristic delay. There is no obvious indication of multiple cortical axes specialized in the processing of different harmonic combinations of pulse and echo. Results of this study serve for a straight comparison of cortical delay-tuning between P. quadridens and the well-studied mustached bat, Pteronotus parnellii. These two species stem from the most recent and most basal nodes in the Pteronotus lineage, respectively. P. quadridens and P. parnellii use comparable heteroharmonic target-range computation strategies even though they do not use biosonar calls of a similar design. P. quadridens uses short constant-frequency (CF)/frequency-modulated (FM) echolocation calls, while P. parnellii uses long CF/FM calls. The ability to perform "heteroharmonic" target-range computations might be an ancestral neuronal specialization of the genus Pteronotus that was subjected to positive Darwinian selection in the evolution. Y1 - 2013 U6 - https://doi.org/10.1121/1.4768794 SN - 0001-4966 VL - 133 IS - 1 SP - 570 EP - 578 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Hechavarria, Julio C. A1 - Macias, Silvio A1 - Vater, Marianne A1 - Voss, Cornelia A1 - Mora, Emanuel C. A1 - Kossl, Manfred T1 - Blurry topography for precise target-distance computations in the auditory cortex of echolocating bats JF - Nature Communications N2 - Echolocating bats use the time from biosonar pulse emission to the arrival of echo (defined as echo delay) to calculate the space depth of targets. In the dorsal auditory cortex of several species, neurons that encode increasing echo delays are organized rostrocaudally in a topographic arrangement defined as chronotopy. Precise chronotopy could be important for precise target-distance computations. Here we show that in the cortex of three echolocating bat species (Pteronotus quadridens, Pteronotus parnellii and Carollia perspicillata), chronotopy is not precise but blurry. In all three species, neurons throughout the chronotopic map are driven by short echo delays that indicate the presence of close targets and the robustness of map organization depends on the parameter of the receptive field used to characterize neuronal tuning. The timing of cortical responses (latency and duration) provides a binding code that could be important for assembling acoustic scenes using echo delay information from objects with different space depths. Y1 - 2013 U6 - https://doi.org/10.1038/ncomms3587 SN - 2041-1723 VL - 4 IS - 10 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Kössl, Manfred A1 - Voss, Cornelia A1 - Mora, Emanuel C. A1 - Macias, Silvio A1 - Föller, Elisabeth A1 - Vater, Marianne T1 - Auditory cortex of newborn bats is prewired for echolocation JF - Nature Communications N2 - Neuronal computation of object distance from echo delay is an essential task that echolocating bats must master for spatial orientation and the capture of prey. In the dorsal auditory cortex of bats, neurons specifically respond to combinations of short frequency-modulated components of emitted call and delayed echo. These delay-tuned neurons are thought to serve in target range calculation. It is unknown whether neuronal correlates of active space perception are established by experience-dependent plasticity or by innate mechanisms. Here we demonstrate that in the first postnatal week, before onset of echolocation and flight, dorsal auditory cortex already contains functional circuits that calculate distance from the temporal separation of a simulated pulse and echo. This innate cortical implementation of a purely computational processing mechanism for sonar ranging should enhance survival of juvenile bats when they first engage in active echolocation behaviour and flight. Y1 - 2012 U6 - https://doi.org/10.1038/ncomms1782 SN - 2041-1723 VL - 3 IS - 2 PB - Nature Publ. Group CY - London ER -