@article{GrohRoessler2020, author = {Groh, Claudia and R{\"o}ssler, Wolfgang}, title = {Analysis of Synaptic Microcircuits in the Mushroom Bodies of the Honeybee}, series = {Insects}, volume = {11}, journal = {Insects}, number = {1}, issn = {2075-4450}, doi = {10.3390/insects11010043}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200774}, year = {2020}, abstract = {Mushroom bodies (MBs) are multisensory integration centers in the insect brain involved in learning and memory formation. In the honeybee, the main sensory input region (calyx) of MBs is comparatively large and receives input from mainly olfactory and visual senses, but also from gustatory/tactile modalities. Behavioral plasticity following differential brood care, changes in sensory exposure or the formation of associative long-term memory (LTM) was shown to be associated with structural plasticity in synaptic microcircuits (microglomeruli) within olfactory and visual compartments of the MB calyx. In the same line, physiological studies have demonstrated that MB-calyx microcircuits change response properties after associative learning. The aim of this review is to provide an update and synthesis of recent research on the plasticity of microcircuits in the MB calyx of the honeybee, specifically looking at the synaptic connectivity between sensory projection neurons (PNs) and MB intrinsic neurons (Kenyon cells). We focus on the honeybee as a favorable experimental insect for studying neuronal mechanisms underlying complex social behavior, but also compare it with other insect species for certain aspects. This review concludes by highlighting open questions and promising routes for future research aimed at understanding the causal relationships between neuronal and behavioral plasticity in this charismatic social insect.}, language = {en} } @article{KirschUllrichKunde2016, author = {Kirsch, Wladimir and Ullrich, Benjamin and Kunde, Wilfried}, title = {Are Effects of Action on Perception Real? Evidence from Transformed Movements}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {12}, doi = {10.1371/journal.pone.0167993}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-178574}, year = {2016}, abstract = {It has been argued that several reported non-visual influences on perception cannot be truly perceptual. If they were, they should affect the perception of target objects and reference objects used to express perceptual judgments, and thus cancel each other out. This reasoning presumes that non-visual manipulations impact target objects and comparison objects equally. In the present study we show that equalizing a body-related manipulation between target objects and reference objects essentially abolishes the impact of that manipulation so as it should do when that manipulation actually altered perception. Moreover, the manipulation has an impact on judgements when applied to only the target object but not to the reference object, and that impact reverses when only applied to the reference object but not to the target object. A perceptual explanation predicts this reversal, whereas explanations in terms of post-perceptual response biases or demand effects do not. Altogether these results suggest that body-related influences on perception cannot as a whole be attributed to extra-perceptual factors.}, language = {en} } @article{FalibeneRocesRoessleretal.2016, author = {Falibene, Augustine and Roces, Flavio and R{\"o}ssler, Wolfgang and Groh, Claudia}, title = {Daily Thermal Fluctuations Experienced by Pupae via Rhythmic Nursing Behavior Increase Numbers of Mushroom Body Microglomeruli in the Adult Ant Brain}, series = {Frontiers in Behavioral Neuroscience}, volume = {10}, journal = {Frontiers in Behavioral Neuroscience}, number = {73}, doi = {10.3389/fnbeh.2016.00073}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146711}, year = {2016}, abstract = {Social insects control brood development by using different thermoregulatory strategies. Camponotus mus ants expose their brood to daily temperature fluctuations by translocating them inside the nest following a circadian rhythm of thermal preferences. At the middle of the photophase brood is moved to locations at 30.8°C; 8 h later, during the night, the brood is transferred back to locations at 27.5°C. We investigated whether daily thermal fluctuations experienced by developing pupae affect the neuroarchitecture in the adult brain, in particular in sensory input regions of the mushroom bodies (MB calyces). The complexity of synaptic microcircuits was estimated by quantifying MB-calyx volumes together with densities of presynaptic boutons of microglomeruli (MG) in the olfactory lip and visual collar regions. We compared young adult workers that were reared either under controlled daily thermal fluctuations of different amplitudes, or at different constant temperatures. Thermal regimes significantly affected the large (non-dense) olfactory lip region of the adult MB calyx, while changes in the dense lip and the visual collar were less evident. Thermal fluctuations mimicking the amplitudes of natural temperature fluctuations via circadian rhythmic translocation of pupae by nurses (amplitude 3.3°C) lead to higher numbers of MG in the MB calyces compared to those in pupae reared at smaller or larger thermal amplitudes (0.0, 1.5, 9.6°C), or at constant temperatures (25.4, 35.0°C). We conclude that rhythmic control of brood temperature by nursing ants optimizes brain development by increasing MG densities and numbers in specific brain areas. Resulting differences in synaptic microcircuits are expected to affect sensory processing and learning abilities in adult ants, and may also promote interindividual behavioral variability within colonies.}, language = {en} } @article{SommerlandtSpaetheRoessleretal.2016, author = {Sommerlandt, Frank M. J. and Spaethe, Johannes and R{\"o}ssler, Wolfgang and Dyer, Adrian G.}, title = {Does Fine Color Discrimination Learning in Free-Flying Honeybees Change Mushroom-Body Calyx Neuroarchitecture?}, series = {PLoS One}, volume = {11}, journal = {PLoS One}, number = {10}, doi = {10.1371/journal.pone.0164386}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147932}, pages = {e0164386}, year = {2016}, abstract = {Honeybees learn color information of rewarding flowers and recall these memories in future decisions. For fine color discrimination, bees require differential conditioning with a concurrent presentation of target and distractor stimuli to form a long-term memory. Here we investigated whether the long-term storage of color information shapes the neural network of microglomeruli in the mushroom body calyces and if this depends on the type of conditioning. Free-flying honeybees were individually trained to a pair of perceptually similar colors in either absolute conditioning towards one of the colors or in differential conditioning with both colors. Subsequently, bees of either conditioning groups were tested in non-rewarded discrimination tests with the two colors. Only bees trained with differential conditioning preferred the previously learned color, whereas bees of the absolute conditioning group, and a stimuli-na{\"i}ve group, chose randomly among color stimuli. All bees were then kept individually for three days in the dark to allow for complete long-term memory formation. Whole-mount immunostaining was subsequently used to quantify variation of microglomeruli number and density in the mushroom-body lip and collar. We found no significant differences among groups in neuropil volumes and total microglomeruli numbers, but learning performance was negatively correlated with microglomeruli density in the absolute conditioning group. Based on these findings we aim to promote future research approaches combining behaviorally relevant color learning tests in honeybees under free-flight conditions with neuroimaging analysis; we also discuss possible limitations of this approach.q}, language = {en} } @article{StejskalStreinzerDyeretal.2015, author = {Stejskal, Kerstin and Streinzer, Martin and Dyer, Adrian and Paulus, Hannes F. and Spaethe, Johannes}, title = {Functional Significance of Labellum Pattern Variation in a Sexually Deceptive Orchid (Ophrys heldreichii): Evidence of Individual Signature Learning Effects}, series = {PLoS One}, volume = {10}, journal = {PLoS One}, number = {11}, doi = {10.1371/journal.pone.0142971}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-137582}, pages = {e0142971}, year = {2015}, abstract = {Mimicking female insects to attract male pollinators is an important strategy in sexually deceptive orchids of the genus Ophrys, and some species possess flowers with conspicuous labellum patterns. The function of the variation of the patterns remains unresolved, with suggestions that these enhance pollinator communication. We investigated the possible function of the labellum pattern in Ophrys heldreichii, an orchid species in which the conspicuous and complex labellum pattern contrasts with a dark background. The orchid is pollinated exclusively by males of the solitary bee, Eucera berlandi. Comparisons of labellum patterns revealed that patterns within inflorescences are more similar than those of other conspecific plants. Field observations showed that the males approach at a great speed and directly land on flowers, but after an unsuccessful copulation attempt, bees hover close and visually scan the labellum pattern for up to a minute. Learning experiments conducted with honeybees as an accessible model of bee vision demonstrated that labellum patterns of different plants can be reliably learnt; in contrast, patterns of flowers from the same inflorescence could not be discriminated. These results support the hypothesis that variable labellum patterns in O. heldreichii are involved in flower-pollinator communication which would likely help these plants to avoid geitonogamy.}, language = {en} } @article{HeisswolfUlmannObermaieretal.2007, author = {Heisswolf, Annette and Ulmann, Sandra and Obermaier, Elisabeth and Mitesser, Oliver and Poethke, Hans J.}, title = {Host plant finding in the specialised leaf beetle Cassida canaliculata: an analysis of small-scale movement behaviour}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-49485}, year = {2007}, abstract = {1. Host plant finding in walking herbivorous beetles is still poorly understood. Analysis of small-scale movement patterns under semi-natural conditions can be a useful tool to detect behavioural responses towards host plant cues. 2. In this study, the small-scale movement behaviour of the monophagous leaf beetle Cassida canaliculata Laich. (Coleoptera: Chrysomelidae) was studied in a semi-natural arena (r = 1 m). In three different settings, a host (Salvia pratensis L., Lamiales: Lamiaceae), a non-host (Rumex conglomeratus Murr., Caryophyllales: Polygonaceae), or no plant was presented in the centre of the arena. 3. The beetles showed no differences in the absolute movement variables, straightness and mean walking speed, between the three settings. However, the relative movement variables, mean distance to the centre and mean angular deviation from walking straight to the centre, were significantly smaller when a host plant was offered. Likewise, the angular deviation from walking straight to the centre tended to decline with decreasing distance from the centre. Finally, significantly more beetles were found on the host than on the non-host at the end of all the trials. 4. It is concluded that C. canaliculata is able to recognise its host plant from a distance. Whether olfactory or visual cues (or a combination of both) are used to find the host plant remains to be elucidated by further studies.}, subject = {K{\"a}fer}, language = {en} } @article{MuellerMeigen2016, author = {M{\"u}ller, Philipp L. and Meigen, Thomas}, title = {M-sequences in ophthalmic electrophysiology}, series = {Journal of Vision}, volume = {16}, journal = {Journal of Vision}, number = {1,15}, doi = {10.1167/16.1.15}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-165796}, pages = {1-19}, year = {2016}, abstract = {The aim of this review is to use the multimedia aspects of a purely digital online publication to explain and illustrate the highly capable technique of m-sequences in multifocal ophthalmic electrophysiology. M-sequences have been successfully applied in clinical routines during the past 20 years. However, the underlying mathematical rationale is often daunting. These mathematical properties of m-sequences allow one not only to separate the responses from different fields but also to analyze adaptational effects and impacts of former events. By explaining the history, the formation, and the different aspects of application, a better comprehension of the technique is intended. With this review we aim to clarify the opportunities of m-sequences in order to motivate scientists to use m-sequences in their future research.}, language = {en} } @article{KirschKunde2022, author = {Kirsch, Wladimir and Kunde, Wilfried}, title = {Perceptual changes after learning of an arbitrary mapping between vision and hand movements}, series = {Scientific Reports}, volume = {12}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-022-15579-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301074}, year = {2022}, abstract = {The present study examined the perceptual consequences of learning arbitrary mappings between visual stimuli and hand movements. Participants moved a small cursor with their unseen hand twice to a large visual target object and then judged either the relative distance of the hand movements (Exp.1), or the relative number of dots that appeared in the two consecutive target objects (Exp.2) using a two-alternative forced choice method. During a learning phase, the numbers of dots that appeared in the target object were correlated with the hand movement distance. In Exp.1, we observed that after the participants were trained to expect many dots with larger hand movements, they judged movements made to targets with many dots as being longer than the same movements made to targets with few dots. In Exp.2, another group of participants who received the same training judged the same number of dots as smaller when larger rather than smaller hand movements were executed. When many dots were paired with smaller hand movements during the learning phase of both experiments, no significant changes in the perception of movements and of visual stimuli were observed. These results suggest that changes in the perception of body states and of external objects can arise when certain body characteristics co-occur with certain characteristics of the environment. They also indicate that the (dis)integration of multimodal perceptual signals depends not only on the physical or statistical relation between these signals, but on which signal is currently attended.}, language = {en} } @article{HalderHammerKleihetal.2013, author = {Halder, Sebastian and Hammer, Eva Maria and Kleih, Sonja Claudia and Bogdan, Martin and Rosenstiel, Wolfgang and Birbaumer, Niels and K{\"u}bler, Andrea}, title = {Prediction of Auditory and Visual P300 Brain-Computer Interface Aptitude}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130327}, pages = {e53513}, year = {2013}, abstract = {Objective Brain-computer interfaces (BCIs) provide a non-muscular communication channel for patients with late-stage motoneuron disease (e.g., amyotrophic lateral sclerosis (ALS)) or otherwise motor impaired people and are also used for motor rehabilitation in chronic stroke. Differences in the ability to use a BCI vary from person to person and from session to session. A reliable predictor of aptitude would allow for the selection of suitable BCI paradigms. For this reason, we investigated whether P300 BCI aptitude could be predicted from a short experiment with a standard auditory oddball. Methods Forty healthy participants performed an electroencephalography (EEG) based visual and auditory P300-BCI spelling task in a single session. In addition, prior to each session an auditory oddball was presented. Features extracted from the auditory oddball were analyzed with respect to predictive power for BCI aptitude. Results Correlation between auditory oddball response and P300 BCI accuracy revealed a strong relationship between accuracy and N2 amplitude and the amplitude of a late ERP component between 400 and 600 ms. Interestingly, the P3 amplitude of the auditory oddball response was not correlated with accuracy. Conclusions Event-related potentials recorded during a standard auditory oddball session moderately predict aptitude in an audiory and highly in a visual P300 BCI. The predictor will allow for faster paradigm selection. Significance Our method will reduce strain on patients because unsuccessful training may be avoided, provided the results can be generalized to the patient population.}, language = {en} } @phdthesis{Schmalz2023, author = {Schmalz, Fabian Dominik}, title = {Processing of behaviorally relevant stimuli at different levels in the bee brain}, doi = {10.25972/OPUS-28882}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-288824}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {The behavior of honeybees and bumblebees relies on a constant sensory integration of abiotic or biotic stimuli. As eusocial insects, a sophisticated intraspecific communication as well as the processing of multisensory cues during foraging is of utter importance. To tackle the arising challenges, both honeybees and bumblebees have evolved a sophisticated olfactory and visual processing system. In both organisms, olfactory reception starts at the antennae, where olfactory sensilla cover the antennal surface in a sex-specific manner. These sensilla house olfactory receptor neurons (ORN) that express olfactory receptors. ORNs send their axons via four tracts to the antennal lobe (AL), the prime olfactory processing center in the bee brain. Here, ORNs specifically innervate spheroidal structures, so-called glomeruli, in which they form synapses with local interneurons and projection neurons (PN). PNs subsequently project the olfactory information via two distinct tracts, the medial and the lateral antennal-lobe tract, to the mushroom body (MB), the main center of sensory integration and memory formation. In the honeybee calyx, the sensory input region of the MB, PNs synapse on Kenyon cells (KC), the principal neuron type of the MB. Olfactory PNs mainly innervate the lip and basal ring layer of the calyx. In addition, the basal ring receives input from visual PNs, making it the first site of integration of visual and olfactory information. Visual PNs, carrying sensory information from the optic lobes, send their terminals not only to the to the basal ring compartment but also to the collar of the calyx. Receiving olfactory or visual input, KCs send their axons along the MB peduncle and terminate in the main output regions of the MB, the medial and the vertical lobe (VL) in a layer-specific manner. In the MB lobes, KCs synapse onto mushroom body output neurons (MBON). In so far barely understood processes, multimodal information is integrated by the MBONs and then relayed further into the protocerebral lobes, the contralateral brain hemisphere, or the central brain among others. This dissertation comprises a dichotomous structure that (i) aims to gain more insight into the olfactory processing in bumblebees and (ii) sets out to broaden our understanding of visual processing in honeybee MBONs. The first manuscript examines the olfactory processing of Bombus terrestris and specifically investigates sex-specific differences. We used behavioral (absolute conditioning) and electrophysiological approaches to elaborate the processing of ecologically relevant odors (components of plant odors and pheromones) at three distinct levels, in the periphery, in the AL and during olfactory conditioning. We found both sexes to form robust memories after absolute conditioning and to generalize towards the carbon chain length of the presented odors. On the contrary, electroantennographic (EAG) activity showed distinct stimulus and sex-specific activity, e.g. reduced activity towards citronellol in drones. Interestingly, extracellular multi-unit recordings in the AL confirmed stimulus and sex-specific differences in olfactory processing, but did not reflect the differences previously found in the EAG. Here, farnesol and 2,3-dihydrofarnesol, components of sex-specific pheromones, show a distinct representation, especially in workers, corroborating the results of a previous study. This explicitly different representation suggests that the peripheral stimulus representation is an imperfect indication for neuronal representation in high-order neuropils and ecological importance of a specific odor. The second manuscript investigates MBONs in honeybees to gain more insights into visual processing in the VL. Honeybee MBONs can be categorized into visually responsive, olfactory responsive and multimodal. To clarify which visual features are represented at this high-order integration center, we used extracellular multi-unit recordings in combination with visual and olfactory stimulation. We show for the first time that information about brightness and wavelength is preserved in the VL. Furthermore, we defined three specific classes of visual MBONs that distinctly encode the intensity, identity or simply the onset of a stimulus. The identity-subgroup exhibits a specific tuning towards UV light. These results support the view of the MB as the center of multimodal integration that categorizes sensory input and subsequently channels this information into specific MBON populations. Finally, I discuss differences between the peripheral representations of stimuli and their distinct processing in high-order neuropils. The unique activity of farnesol in manuscript 1 or the representation of UV light in manuscript 2 suggest that the peripheral representation of a stimulus is insufficient as a sole indicator for its neural activity in subsequent neuropils or its putative behavioral importance. In addition, I discuss the influence of hard-wired concepts or plasticity induced changes in the sensory pathways on the processing of such key stimuli in the peripheral reception as well as in high-order centers like the AL or the MB. The MB as the center of multisensory integration has been broadly examined for its olfactory processing capabilities and receives increasing interest about its visual coding properties. To further unravel its role of sensory integration and to include neglected modalities, future studies need to combine additional approaches and gain more insights on the multimodal aspects in both the input and output region.}, subject = {Biene}, language = {en} }