TY  - JOUR
A1  - Groh, Claudia
A1  - Rössler, Wolfgang
T1  - Analysis of Synaptic Microcircuits in the Mushroom Bodies of the Honeybee
JF  - Insects
N2  - 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.
KW  - mushroom body
KW  - microglomeruli
KW  - projection neurons
KW  - Kenyon cells
KW  - dendritic specializations
KW  - structural synaptic plasticity
KW  - behavioral plasticity
KW  - vision
KW  - olfaction
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200774
SN  - 2075-4450
VL  - 11
IS  - 1
ER  - 
TY  - JOUR
A1  - Stieb, Sara Mae
A1  - Kelber, Christina
A1  - Wehner, Rüdiger
A1  - Rössler, Wolfgang
T1  - Antennal-Lobe Organization in Desert Ants of the Genus Cataglyphis
JF  - Brain, Behavior and Evolution
N2  - Desert ants of the genus Cataglyphis possess remarkable visual navigation capabilities. Although Cataglyphis species lack a trail pheromone system, Cataglyphis fortis employs olfactory cues for detecting nest and food sites. To investigate potential adaptations in primary olfactory centers of the brain of C. fortis, we analyzed olfactory glomeruli (odor processing units) in their antennal lobes and compared them to glomeruli in different Cataglyphis species. Using confocal imaging and 3D reconstruction, we analyzed the number, size and spatial arrangement of olfactory glomeruli in C. fortis, C.albicans, C.bicolor, C.rubra, and C.noda. Workers of all Cataglyphis species have smaller numbers of glomeruli (198–249) compared to those previously found in olfactory-guided ants. Analyses in 2 species of Formica – a genus closely related to Cataglyphis – revealed substantially higher numbers of olfactory glomeruli (c. 370), which is likely to reflect the importance of olfaction in these wood ant species. Comparisons between Cataglyphis species revealed 2 special features in C. fortis. First, with c. 198 C. fortis has the lowest number of glomeruli compared to all other species. Second, a conspicuously enlarged glomerulus is located close to the antennal nerve entrance. Males of C. fortis possess a significantly smaller number of glomeruli (c. 150) compared to female workers and queens. A prominent male-specific macroglomerulus likely to be involved in sex pheromone communication occupies a position different from that of the enlarged glomerulus in females. The behavioral significance of the enlarged glomerulus in female workers remains elusive. The fact that C. fortis inhabits microhabitats (salt pans) that are avoided by all other Cataglyphis species suggests that extreme ecological conditions may not only have resulted in adaptations of visual capabilities, but also in specializations of the olfactory system.
KW  - olfactory glomeruli
KW  - plasticity
KW  - ant
KW  - antennal lobe
KW  - glomerulus
KW  - insects
KW  - interspecific comparison
KW  - macroglomerulus
KW  - olfaction
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196815
SN  - 0006-8977
SN  - 1421-9743
N1  - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
VL  - 77
IS  - 3
ER  - 
TY  - THES
A1  - Langenhan, Tobias
T1  - Ciliary neurotrophic factor (CNTF) im olfaktorischen System von Ratten und Mäusen
T1  - Ciliary neurotrophic factor (CNTF) in the olfactory system of rats and mice
N2  - Das olfaktorische System ist aufgrund seiner lebenslangen regenerativen Kapazität, seines Reichtums an neurotrophen Faktoren und der relativ guten Zugänglichkeit für Manipulationen ein attraktiver Gegenstand neurobiologischer Forschung. In der vorliegenden Arbeit wurde die Lokalisation und mögliche Funktion des ziliären neurotrophen Faktors (CNTF) in der primären Geruchsbahn mit Hilfe immunhistochemischer Methoden untersucht. Es konnte gezeigt werden, dass die CNTF-Ir bei Ratten und Mäusen in den olfaktorischen Gliazellen (Ensheathingzellen) lokalisiert ist. Elektronenmikroskopische Aufnahmen belegten ein zytoplasmatisches und nukleäres Vorkommen der CNTF-Ir innerhalb der EC. Ein neues und überraschendes Ergebnis der Arbeit ist, dass CNTF in individuellen olfaktorischen Neuronen vorkommt. Bislang wurde CNTF lediglich in Gliazellen des zentralen und peripheren Nervensystems nachgewiesen. Die weitere Charakterisierung der epithelialen CNTF-ir Neurone kennzeichnete diese als reife olfaktorische Nervenzellen. Die CNTF-Ir war mit dem olfaktorischen Markerprotein (OMP) kolokalisiert, einem Marker ausschließlich reifer ON und wies keine Kolokalisation mit dem Growth associated protein 43 (GAP-43) auf, dessen Expression unreife Riechsinneszellen kennzeichnet. CNTF könnte einerseits an lebenslang fortwährenden De- und/oder Regenerationsvorgängen des olfaktorischen Epithels beteiligt sein. Die Exposition der Riechschleimhaut gegenüber infektiösen, physikalischen und chemischen Noxen bedingt den ständigen Verlust olfaktorischer Neurone und deren lebenslange Regeneration aus neuronalen Vorläuferzellen im olfaktorischen Epithel. Die Zellkerne CNTF-ir ON wiesen in der Mehrzahl keine degenerativen Veränderungen wie Kondensierung und Fragmentierung auf, wie es bei geschädigten und untergehenden Zellen beobachtet wird. Im olfaktorischen Epithel zeigte sich des weiteren keine neuronale Kolokalisation von CNTF mit der aktivierten Caspase-3, einem Exekutorenzym der Apoptose, wie man es bei apoptotisch degenerierenden Neuronen findet. Nach Läsionen des olfaktorischen Epithels von Mäusen, die nekrotische Zelluntergänge auslösen, konnte kein gesteigertes Vorkommen von CNTF-ir ON gezeigt werden. Eine Einbindung von CNTF in die Mechanismen neuronaler Degeneration erscheint nach den Ergebnissen verschiedener Experimente wenig wahrscheinlich. Eine zweite Erklärung für das individuelle neuronale Auftreten der CNTF-Ir bot die Annahme, dass CNTF mit der Expression olfaktorischer Rezeptorproteine vergesellschaftet sein könnte. Dreidimensionale Rekonstruktionen von Paaren von BO bei Ratten und Mäusen zeigte, dass die Axone CNTF-ir ON in Glomeruli olfactorii projizierten, die bilateralsymmetrisch in beiden BO eines Tieres lokalisiert waren. Diese Symmetrie findet man ebenfalls bei den Projektionen der ON, die das gleiche olfaktorische Rezeptorprotein exprimieren. Die Lokalisation der CNTF-ir innervierten Glomeruli war interindividuell ähnlich, ihre Anzahl wies jedoch erhebliche Unterschiede auf. Dieses Phänomen lässt sich mit Befunden vergleichen, die im Rahmen von olfaktorischen Aktivitätsstudien bei Mäusen und Ratten erhoben wurden. Dabei beobachtete man eine Erhöhung der Anzahl aktivierter Glomeruli mit steigenden Geruchsstoffkonzentrationen. Auffallend war eine deutliche Übereinstimmung des Verteilungsmusters der CNTF-ir Glomeruli mit dem in der Literatur dargestellten Verteilungsmuster von Glomeruli, die durch Uringerüche aktiviert werden. Die räumliche Rekonstruktion der BO und die Darstellung der Position der CNTF-ir innervierten Glomeruli legt demnach eine neue mögliche Funktion von CNTF im olfaktorischen System nah: dessen Einbindung in Phänomene der Aktivität olfaktorischer Nervenzellen und plastischer Prozesse, die an der ersten Synapse der Geruchsbahn stattfinden. In der vorliegenden Arbeit konnte durch die Anwendung von klassischen Methoden der anatomisch-histologischen Forschung die Lokalisation von CNTF in der primären Geruchsbahn geklärt werden. Die Befunde führten zu weiteren Hypothesen hinsichtlich seiner funktionellen Einbindung in die olfaktorische Informationsverarbeitung, denen in zukünftigen Studien nachgegangen werden wird.
N2  - The olfactory system is bestowed with a set of remarkable features that render it an intriguing object for neurobiological research. It possesses the livelong capacity to regenerate, it displays an extraordinary wealth of neurotrophic factors and it is easily accessible to experimental manipulations. The current study aimed to deliver a comprehensive description of the localization and possible function of ciliary neurotrophic factor (CNTF) in the primary olfactory pathway by means of immunohistochemical methods. It could be shown that CNTF-immunoreactivity in rats and mice was localized in olfactory glia cells (ensheathing cells); using electron microscopy it was demonstrated that CNTF-immunoreactivity occurred both in the cytoplasm and the nucleus of ensheathing cells. Additionally, it was shown that CNTF can be also found in individual olfactory sensory neurons (OSN). Thus far, CNTF was known to be localized in peripheral and central glial cells only. Further characterization of neuroepithelial CNTF-occurrence revealed that CNTF-immunoreactive OSN are mature neurons displaying colocalization with the olfactory marker protein (OMP), a distinct marker protein for mature OSN. This was in line with absent colocalization of CNTF with Growth associated protein 43 (GAP-43) immunoreactivity, a marker of maturing OSN. CNTF could be implicated in the ongoing processes and neurode- and regeneration that take place in the olfactory epithelium. The olfactory mucosa is constantly exposed to the outer environment including noxious substances such as infectious agents, and extreme physical or chemical conditions. Hence, a permanent loss of OSN occurs which is counterbalanced with constant regeneration of neurons from neural precursor cells residing in the epithelium. Nuclei of CNTF-immunoreactive OSN did not display degenerative signs such as condensation or fragmentation that mark harmed degenerating cells. In addition to that no colocalization of CNTF and the apoptotic executor enzyme activated capsase-3 could be found in the olfactory epithelium. Even after chemical lesions of the olfactory epithelium of mice that cause necrotic cell death no enhanced incidence of CNTF-immunoreactive OSN was noted. Therefore, an implication of CNTF in neuronal degenerative processes in the olfactory mucosa seems unlikely. An alternative explanation for the individual neuronal localization of CNTF-immunoreactivity relied on the assumption that CNTF could be associated with the expression of olfactory receptor proteins (ORP). Three-dimensional reconstructions of rat and mice olfactory bulb pairs demonstrated the axonal projections of CNTF-immunoreactive OSN in olfactory glomeruli, which where found to be located at bilaterally symmetrical positions. This symmetry is also notable for OSN that express the identical ORP. The localization of CNTF-immunoreactive glomeruli was interindividually similar although they substantially differed in their numbers between animals. This phenomenon is reminiscent of results from olfactory activity studies obtained from rats and mice. It was observed that an increasing number of olfactory glomeruli is recruited due to an elevation of the odour concentration that the animals was exposed to. The distribution pattern of CNTF-immunoreactive glomeruli was comparable to glomerular activity maps elicited by urine odours. Hence, the three-dimensional reconstruction of olfactory bulbs and the localization of CNTF-immunoreactive glomeruli indicate a possible role for CNTF in activity-dependent processes of OSN and in neuroplastic mechanisms that occur at the first synapse of the primary olfactory pathway. In the current dissertation the localization of CNTF in the primary olfactory pathway was untangled by means of classical anatomical-histological techniques. The results yielded further hypotheses regarding the functional relationship of CNTF with olfactory information processing, which will be followed by future investigations.
KW  - CNTF
KW  - neurotrophe Faktoren
KW  - Neuroregeneration
KW  - Olfaktion
KW  - Geruchssystem
KW  - CNTF
KW  - neurotrophic facors
KW  - neuroregeneration
KW  - olfaction
KW  - olfactory system
Y1  - 2004
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-16009
ER  - 
TY  - JOUR
A1  - Falibene, Augustine
A1  - Roces, Flavio
A1  - Rössler, Wolfgang
A1  - Groh, Claudia
T1  - Daily Thermal Fluctuations Experienced by Pupae via Rhythmic Nursing Behavior Increase Numbers of Mushroom Body Microglomeruli in the Adult Ant Brain
JF  - Frontiers in Behavioral Neuroscience
N2  - 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.
KW  - microglomeruli
KW  - temperature
KW  - broodtranslocation
KW  - camponotus ants
KW  - olfaction
KW  - vision
KW  - synapticplasticity
KW  - mushroom body
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-146711
VL  - 10
IS  - 73
ER  - 
TY  - THES
A1  - Frey, Monika
T1  - Effects and mechanisms of a putative human pheromone
T1  - Effekte und Mechanismen eines putativen menschlichen Pheromons
N2  - There is evidence that pheromones are communicative signals in animals. However, the existence and function of human pheromones are still under discussion. During the last years several substances have been labeled as putative human pheromones and especially 4,16–androstadien-3-one (androstadienone), found in male and female sweat, became subject of intense investigation. In contrast to common odors androstadienone presumably modulates human physiological and psychological reactions. Data suggest that androstadienone might influence the processing of visual cues, specifically faces or affective stimuli, via projections from the fusiform gyrus and the amygdala. Moreover, attentional processes may be modulated, which is supported by explicit and implicit behavioral data. This thesis includes three experimental studies examining effects of androstadienone exposure on behavioral and cortical reactions to visual and emotional stimuli. The main hypotheses were that androstadienone might influence human behavior to and perception of visual cues. The first study sought to clarify androstadienone effects on attention-related reactions as well as on behavioral tendencies. Motoric approach-avoidance reactions in response to happy and angry facial expressions were investigated in 30 women and 32 men. Participants either inhaled androstadienone or a control solution, without knowing the real content, while performing the following task: they had to push away or to pull towards them a joystick as fast as possible in reaction to either an angry or a happy cartoon face, which was presented on a computer screen. Results showed that androstadienone modulated the participant´s task performance by accelerating the reaction speed compared to the control compound. Faster reactions were observed particularly when reacting to angry faces but not when reacting to happy faces. This might be explained by the finding that human body odors, the source of androstadienone, were found to activate the human fear system, i.e. modulating fear-related attentional processes. Therefore, the quicker reaction towards angry faces with exposure to androstadienone could be due to an enhanced allocation of attentional resources towards fear-related cues like angry faces. Results also showed that androstadienone enhanced men´s approach tendency towards faces independent of emotional expressions. This observation might be explained by androstadienone´s former shown ability to improve attractiveness ratings of other persons. In this regard, the endogenous odor might enhance evaluations of faces in men and, thus, might improve their willingness to approach social stimuli. In contrast to men, women already showed in the control condition higher approach tendency towards faces. Therefore, androstadienone might rather maintain than enhance the approach score in women. In the second study event-related brain potentials (ERPs) triggered by social and non-social visual stimuli were investigated by means of electroencephalography. In a double-blind between-subjects design 51 women participated. Twenty-eight women inhaled androstadienone, whereas 23 women inhaled a control solution. Four different picture categories, i.e. real faces, pictures with couples, pictures with social and non-social scenes, each including three different valence categories, i.e. positive, negative and neutral, should clarify the stimulus type or context androstadienone is acting on. The androstadienone compared to the control odor did not influence brain responses significantly. Explorative analyses, however, suggested that androstadienone influences the processing of faces. While in the control group angry faces elicited larger P300 amplitudes than happy faces, the androstadienone group showed similar P300 amplitudes concerning all emotional expressions. This observation tentatively indicates that the endogenous odor might indeed affect the neuronal responses to emotional facial stimuli, especially late components reflecting evaluative processes. However, this observation has to be verified and further investigated, in particular whether androstadienone caused reduced responses to angry faces or enhanced responses to happy faces. The third study investigated androstadienone effects on face processing especially in men. ERPs elicited by happy, angry and neutral cartoon faces, which were presented on a computer screen, were measured while 16 men, not knowing the applicated odor, inhaled either androstadienone or a control solution. Exposure to androstadienone significantly increased later neuronal responses, the P300 amplitude. This belated component of the ERP reflects attention allocation and evaluative processes towards important stimuli. Therefore, androstadienone might facilitate central nervous face processing by enhancing attention towards these stimuli. In sum, the current results corroborate the notion of androstadienone as an active social chemosignal. In minute amounts and not detectable as an odor it influenced cortical and motoric reactions. Therefore, it might be concluded that androstadienone indeed affects cognitive functions like attentional processes and in turn affects our behavior. The current results further support the notion that androstadienone acts like a human modulator pheromone, namely modulating ongoing behavior or a psychological reaction to a particular context, changing stimulus sensitivity, salience and sensory-motor integration. However, these conclusions remain tentative until further replication takes place, best in ecologically valid environments. Furthermore, one has to keep in mind that the current studies could not replicate several previous findings and could not verify some hypotheses assuming communicative effects of androstadienone. Thus, the main assumption of this thesis that androstadienone is an active chemosignal is still challenged. Also, whether the term “pheromone” is indeed suitable to label androstadienone remains open.
N2  - Pheromone sind als Kommunikationssubstanzen im Tierreich unabkömmlich. Ob jedoch menschliche Pheromone tatsächlich existieren, wird noch immer diskutiert. Während der letzten Jahre wurden mehrere Substanzen als putative menschliche Pheromone bezeichnet. Unter diesen wurde v.a. 4,16–androstadien-3-on (Androstadienon), eine Komponente des männlichen und weiblichen Schweißes, intensiv untersucht. Bisherige Ergebnisse deuten darauf hin, dass Androstadienon im Gegensatz zu herkömmlichen Duftstoffen die Verarbeitung visueller Stimuli, v.a. von Gesichtern und von affektiven Stimuli, vermutlich über eine Modulation der Aktivität des Gyrus fusiformis und der Amygdala beeinflussen kann. Außerdem könnten Aufmerksamkeitsprozesse durch Androstadienon beeinflusst sein, was durch explizite und implizite Verhaltensdaten angedeutet wird. Diese Doktorarbeit untersuchte in drei verschiedenen Studien die Effekte von Androstadienon auf kortikale Reaktionen und Verhalten bei Männern und Frauen, während diese mit visuellen, insbesondere emotionalen Stimuli konfrontiert wurden. Die Haupthypothesen waren, dass Androstadienon die Wahrnehmung visueller Stimuli und menschliches Verhalten gegenüber diesen beeinflussen könnte. Die erste Studie untersuchte Androstadienoneffekte auf aufmerksamkeitsabhängige, motorische Reaktionen sowie auf Verhaltenstendenzen. Motorisches Annäherungs- und Vermeidungsverhalten als Reaktion auf freudige und ärgerliche Gesichter wurden bei 30 Frauen und 32 Männern untersucht. Während diese entweder Androstadienon oder einen Kontrollduft inhalierten, ohne zu wissen welchen, mussten sie so schnell wie möglich einen Joystick jeweils wegdrücken oder zu sich heranziehen, sobald entweder ein freudiges oder ärgerliches Gesicht auf einem Computerbildschirm erschien. Im Vergleich zum Kontrollduft beschleunigte Androstadienon die Reaktionsgeschwindigkeit spezifisch auf ärgerliche Gesichter unabhängig von der Bewegungsrichtung. Dies könnte damit zusammenhängen, dass menschlicher Körpergeruch, die Quelle von Androstadienon, das Angstsystem im menschlichen Gehirn aktiviert. Die schnellere Reaktion auf ärgerliche Gesichter durch den endogenen Geruch könnte dementsprechend auf eine erhöhte Bereitstellung von Aufmerksamkeitsressourcen für angstverwandte Stimuli, wie ärgerliche Gesichter, zurückzuführen sein. Zusätzlich zeigten die Ergebnisse, dass Androstadienon unabhängig vom Emotionsausdruck die Annäherungstendenz bei Männern zu den Gesichtern erhöht. Diese Beobachtung könnte durch die in einer früheren Studie gezeigte Eigenschaft von Androstadienon, die Attraktivitätsbewertungen anderer Personen zu erhöhen, erklärt werden. Demnach könnte der endogene Duftstoff bei Männern die Bewertung von Gesichtern verbessern und folglich die Bereitschaft, sich sozialen Stimuli anzunähern, erhöhen. Im Gegensatz zu Männern zeigten Frauen schon in der Kontrollbedingung eine stärkere Annäherungstendenz zu Gesichtern. Folglich könnte Androstadienon diese verstärkte Tendenz bei Frauen eher aufrechterhalten als verstärken. In der zweiten Studie wurden kortikale Reaktionen, d.h. ereigniskorrelierte Gehirnpotentiale (EKPs), auf soziale und nicht-soziale visuelle Bilder bei 28 Frauen, die Androstadienon rochen, und bei 23 Frauen die einem Kontrollduft ausgesetzt waren, mit Elektroenzephalographie untersucht. Allen Teilnehmerinnen war der Inhalt des applizierten Duftstoffes nicht bewusst. Vier verschiedene Bildkategorien, d.h. echte Gesichter, Bilder mit Paaren, Bilder mit Gruppen von Menschen und Bilder ohne Personen, mit jeweils positiver, negativer und neutraler Valenz wurden verwendet, um den Wirkkontext von Androstadienon zu klären. Androstadienon beeinflusste die Hirnreaktionen auf diese Stimuli nicht signifikant. Explorative Analysen deuteten aber an, dass Androstadienon die späte EKP Komponente, P300, beeinflussen kann. Während in der Kontrollgruppe ärgerliche Gesichter größere P300 Amplituden auslösten als freudige Gesichter, erzeugten in der Androstadienongruppe alle emotionalen Ausdrücke ähnliche P300 Amplituden. Dies könnte andeuten, dass Androstadienon attentive oder evaluative Prozesse bei der Gesichtsverarbeitung beeinflusst, was aber durch weitere Studien bestätigt und präzisiert werden muss. Die dritte Studie untersuchte Androstadienoneffekte auf zentralnervöse Prozesse der Gesichtsverarbeitung von Männern. EKPs auf freudige, ärgerliche und neutrale Cartoongesichter wurden aufgezeichnet, während 16 Männer entweder Androstadienon oder den Kontrollduft inhalierten, ohne jeweils zu wissen welchen. Androstadienon verstärkte eine späte neuronale Reaktion, die P300 Komponente, auf alle Gesichter signifikant. Diese Komponente des ereigniskorrelierten Potenzials spiegelt die Bereitstellung von Aufmerksamkeit auf wichtige Stimuli wider. Androstadienon könnte folglich die zentralnervöse Verarbeitung von Gesichtern erleichtern, indem es Aufmerksamkeit auf diese Stimuli lenkt. Zusammenfassend stützen die genannten Ergebnisse die Annahme, dass Androstadienon ein aktives soziales Chemosignal ist. In winzigen, bewusst nicht wahrnehmbaren Mengen beeinflusste es kortikale und motorische Reaktionen. Demzufolge scheint Androstadienon tatsächlich auf kognitive Funktionen wie Aufmerksamkeit zu wirken und deshalb unser Verhalten beeinflussen zu können. Die aktuellen Ergebnisse unterstützen auch die Annahme, dass Androstadienon ein menschliches Modulatorpheromon ist, das in einem speziellen Kontext unser Verhalten und eine psychologische Reaktion moduliert und Stimulussensitivität und die Sensor-Motor-Integration ändert. Dennoch müssen diese Interpretationen als vorläufig betrachtet werden bis die dargestellten Ergebnisse auch unter ökologisch validen Bedingungen repliziert werden konnten. Außerdem muss berücksichtigt werden, dass in dieser Doktorarbeit einige frühere Ergebnisse und einige Hypothesen bezüglich kommunikativer Effekte von Androstadienone nicht bestätigt werden konnten. Deshalb kann die Annahme, dass Androstadienon ein aktives Chemosignal ist, immer noch in Frage gestellt werden. Auch ob Androstadienon tatsächlich als menschliches Pheromon bezeichnet werden sollte bleibt offen.
KW  - Pheromon
KW  - Aufmerksamkeit
KW  - Mensch
KW  - Androstadienon
KW  - ereigniskorreliertes Potential
KW  - Antwortverhalten
KW  - Geruchssinn
KW  - androstadienone
KW  - humans
KW  - olfaction
KW  - pheromone
KW  - behavior
KW  - attention
Y1  - 2011
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-72292
ER  - 
TY  - THES
A1  - Weiland, Romy
T1  - Facial reactions in response to gustatory and olfactory stimuli in healthy adults, patients with eating disorders, and patients with attention-deficit hyperactivity disorder
T1  - Mimische Reaktionen auf Geschmacks- und Geruchsreize bei gesunden Erwachsenen, Patientinnen mit Essstörungen und Patientinnen mit Aufmerksamkeitsdefizit/Hyperaktivitätsstörung
N2  - The aim of this project was to investigate whether reflex-like innate facial reactions to tastes and odors are altered in patients with eating disorders. Qualitatively different tastes and odors have been found to elicit specific facial expressions in newborns. This specificity in newborns is characterized by positive facial reactions in response to pleasant stimuli and by negative facial reactions in response to unpleasant stimuli. It is, however, unclear, whether these specific facial displays remain stable during ontogeny (1). Despite the fact that several studies had shown that taste-and odor-elicited facial reactions remain quite stable across a human’s life-span, the specificity of research questions, as well as different research methods, allow only limited comparisons between studies. Moreover, the gustofacial response patterns might be altered in pathological eating behavior (2). To date, however, the question of whether dysfunctional eating behavior might alter facial activity in response to tastes and odors has not been addressed. Furthermore, changes in facial activity might be linked to deficient inhibitory facial control (3). To investigate these three research questions, facial reactions in response to tastes and odors were assessed. Facial reactions were analyzed using the Facial Action Coding System (FACS, Ekman & Friesen, 1978; Ekman, Friesen, & Hager, 2002) and electromyography.
N2  - Ziel dieses Projektes war es zu untersuchen, ob spezifische, mimische Reaktionen auf Geschmacks- und Geruchsreize bei Patientinnen mit Essstörungen verändert sind. Bei Neugeborenen rufen qualitativ verschiedene Geschmacksreize und Geruchsreize spezifische mimische Reaktionsmuster hervor. Diese Spezifität zeichnet sich infolge angenehmer Reize durch positive mimische Reaktionen und infolge unangenemher Reize durch negative mimische Reaktionen aus. Es ist jedoch unklar, ob diese spezifischen Reaktionsmuster während der ontogentischen Entwicklung stabil bleibe (1). Trotz der Befunde, dass geschmacks- und geruchsinduzierte mimische Reaktionen bei Erwachsenen relativ stabil bleiben, erlauben spezifische Forschungsfragen und verschiedene Methoden nur einen begrenzten Vergleich zwischen den Studien. Darüber hinaus könnten die gustofazialen Reaktionsmuster bei Patientinnen mit Essstörungen verändert sein (2). Diese Frage wurde jedoch bisher nicht untersucht. Weiterhin könnten Veränderungen in den mimischen Reaktionen bei essgestörten Patientinnen durch eine defizitäre Hemmungskontrolle bedingt sein (3). Zur Klärung dieser drei Fragestellungen wurden mimische Reaktionen auf Geschmacks- und Geruchsreize erfasst. Die Mimikanalyse erfolgte mit Hilfe des Facial Action Coding Systems (FACS, Ekman & Friesen, 1978; Ekman, Friesen, & Hager, 2002) und des Elektromyogramms.
KW  - Mimik
KW  - Geschmack
KW  - Geruch
KW  - Essstörung
KW  - Aufmerksamkeits-Defizit-Syndrom
KW  - facial expressions
KW  - gustation
KW  - olfaction
KW  - eating disorders
KW  - ADHD
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-51759
ER  - 
TY  - JOUR
A1  - Chen, Yi-chun
A1  - Gerber, Bertram
T1  - Generalization and discrimination tasks yield concordant measures of perceived distance between odours and their binary mixtures in larval Drosophila
JF  - The Journal of Experimental Biology
N2  - Similarity between odours is notoriously difficult to measure. Widely used behavioural approaches in insect olfaction research are cross-adaptation, masking, as well as associative tasks based on olfactory learning and the subsequent testing for how specific the established memory is. A concern with such memory-based approaches is that the learning process required to establish an odour memory may alter the way the odour is processed, such that measures of perception taken at the test are distorted. The present study was therefore designed to see whether behavioural judgements of perceptual distance are different for two different memory-based tasks, namely generalization and discrimination. We used odour-reward learning in larval Drosophila as a study case. In order to challenge the larvae's olfactory system, we chose to work with binary mixtures and their elements (1-octanol, n-amyl acetate, 3-octanol, benzaldehyde and hexyl acetate). We determined the perceptual distance between each mixture and its elements, first in a generalization task, and then in a discrimination task. It turns out that scores of perceptual distance are correlated between both tasks. A re-analysis of published studies looking at element-to-element perceptual distances in larval reward learning and in adult punishment learning confirms this result. We therefore suggest that across a given set of olfactory stimuli, associative training does not grossly alter the pattern of perceptual distances.
KW  - discrimination
KW  - drosophila melanogaster
KW  - generalization
KW  - memory
KW  - olfaction
KW  - perception
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-121625
VL  - 217
IS  - 12
ER  - 
TY  - JOUR
A1  - Heisswolf, Annette
A1  - Ulmann, Sandra
A1  - Obermaier, Elisabeth
A1  - Mitesser, Oliver
A1  - Poethke, Hans J.
T1  - Host plant finding in the specialised leaf beetle Cassida canaliculata: an analysis of small-scale movement behaviour
N2  - 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.
KW  - Käfer
KW  - Blattkäfer
KW  - Ampfer
KW  - Wiesensalbei
KW  - Arena experiment
KW  - Coleoptera
KW  - Chrysomelidae
KW  - olfaction
KW  - Rumex
KW  - Salvia pratensis
KW  - vision
KW  - walking
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-49485
ER  - 
TY  - JOUR
A1  - Kropf, Jan
A1  - Rössler, Wolfgang
T1  - In-situ recording of ionic currents in projection neurons and Kenyon cells in the olfactory pathway of the honeybee
JF  - PLoS ONE
N2  - The honeybee olfactory pathway comprises an intriguing pattern of convergence and divergence: ~60.000 olfactory sensory neurons (OSN) convey olfactory information on ~900 projection neurons (PN) in the antennal lobe (AL). To transmit this information reliably, PNs employ relatively high spiking frequencies with complex patterns. PNs project via a dual olfactory pathway to the mushroom bodies (MB). This pathway comprises the medial (m-ALT) and the lateral antennal lobe tract (l-ALT). PNs from both tracts transmit information from a wide range of similar odors, but with distinct differences in coding properties. In the MBs, PNs form synapses with many Kenyon cells (KC) that encode odors in a spatially and temporally sparse way. The transformation from complex information coding to sparse coding is a well-known phenomenon in insect olfactory coding. Intrinsic neuronal properties as well as GABAergic inhibition are thought to contribute to this change in odor representation. In the present study, we identified intrinsic neuronal properties promoting coding differences between PNs and KCs using in-situ patch-clamp recordings in the intact brain. We found very prominent K+ currents in KCs clearly differing from the PN currents. This suggests that odor coding differences between PNs and KCs may be caused by differences in their specific ion channel properties. Comparison of ionic currents of m- and l-ALT PNs did not reveal any differences at a qualitative level.
KW  - action potentials
KW  - olfaction
KW  - honeybee
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175869
VL  - 13
IS  - 1
ER  - 
TY  - JOUR
A1  - Brill, Martin F.
A1  - Meyer, Anneke
A1  - Roessler, Wolfgang
T1  - It takes two—coincidence coding within the dual olfactory pathway of the honeybee
JF  - Frontiers in Physiology
N2  - To rapidly process biologically relevant stimuli, sensory systems have developed a broad variety of coding mechanisms like parallel processing and coincidence detection. Parallel processing (e.g., in the visual system), increases both computational capacity and processing speed by simultaneously coding different aspects of the same stimulus. Coincidence detection is an efficient way to integrate information from different sources. Coincidence has been shown to promote associative learning and memory or stimulus feature detection (e.g., in auditory delay lines). Within the dual olfactory pathway of the honeybee both of these mechanisms might be implemented by uniglomerular projection neurons (PNs) that transfer information from the primary olfactory centers, the antennal lobe (AL), to a multimodal integration center, the mushroom body (MB). PNs from anatomically distinct tracts respond to the same stimulus space, but have different physiological properties, characteristics that are prerequisites for parallel processing of different stimulus aspects. However, the PN pathways also display mirror-imaged like anatomical trajectories that resemble neuronal coincidence detectors as known from auditory delay lines. To investigate temporal processing of olfactory information, we recorded PN odor responses simultaneously from both tracts and measured coincident activity of PNs within and between tracts. Our results show that coincidence levels are different within each of the two tracts. Coincidence also occurs between tracts, but to a minor extent compared to coincidence within tracts. Taken together our findings support the relevance of spike timing in coding of olfactory information (temporal code).
KW  - olfaction
KW  - mushroom body
KW  - insect
KW  - coincidence
KW  - multi-electrode-recording
KW  - antennal lobe
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126179
VL  - 6
IS  - 208
ER  -