Extending in vitro conditioning in Aplysia to analyze operant and classical processes in the same preparation.

Operant and classical conditioning are major processes shaping behavioral responses in all animals. Although the understanding of the mechanisms of classical conditioning has expanded significantly, the understanding of the mechanisms of operant conditioning is more limited. Recent developments in Aplysia are helping to narrow the gap in the level of understanding between operant and classical conditioning, and have raised the possibility of studying the neuronal processes underlying the interaction of operant and classical components in a relatively complex learning task. In the present study, we describe a first step toward realizing this goal, by developing a single in vitro preparation in which both operant and classical conditioning can be studied concurrently. The new paradigm reproduced previously published results, even under more conservative and homogenous selection criteria and tonic stimulation regime. Moreover, the observed learning was resistant to delay, shortening, and signaling of reinforcement.

In vitro analog of classical conditioning of feeding behavior in aplysia.

The feeding behavior of Aplysia californica can be classically conditioned using tactile stimulation of the lips as a conditioned stimulus (CS) and food as an unconditioned stimulus (US). Moreover, several neural correlates of classical conditioning have been identified. The present study extended previous work by developing an in vitro analog of classical conditioning and by investigating pairing-specific changes in neuronal and synaptic properties. The preparation consisted of the isolated cerebral and buccal ganglia. Electrical stimulation of a lip nerve (AT4) and a branch of the esophageal nerve (En2) served as the CS and US, respectively. Three protocols were used: paired, unpaired, and US alone. Only the paired protocol produced a significant increase in CS-evoked fictive feeding. At the cellular level, classical conditioning enhanced the magnitude of the CS-evoked synaptic input to pattern-initiating neuron B31/32. In addition, paired training enhanced both the magnitude of the CS-evoked synaptic input and the CS-evoked spike activity in command-like neuron CBI-2. The in vitro analog of classical conditioning reproduced all of the cellular changes that previously were identified following behavioral conditioning and has led to the identification of several new learning-related neural changes. In addition, the pairing-specific enhancement of the CS response in CBI-2 indicates that some aspects of associative plasticity may occur at the level of the cerebral sensory neurons.

Bodily and Embodied: Being Human in the Tradition of the Hebrew Bible

A depiction of the ancient Hebrew understanding of the human being must take into account the fact that the Bible does not contain a systematic anthropology, but unfolds the multiplicity of human existence inductively, aspectively, and in narrative fashion. In comparison to Greek body/soul dualism, but also in the context of body-(de-)construction and gender debates, this circumstance makes it a treasure trove of interesting, often contrasting recollections and insights with liberating potential. This assertion will be illustrated concretely in terms of the nexus points of the human body (throat, heart, and womb), the relationship of humans to animals and angels, and the questions of the power and value of a human being.

Alles koscher? Die Renaissance jüdischer Restaurants zwischen Tradition und Innovation

Die Erfindung eines jüdischen „ethnic food“ im urbanen Kontext Die religiösen Speisegesetze, die Kaschrut, sind heute nur noch für eine kleine Minderheit der Juden im Alltag verbindlich. In urbanen Zentren Europas finden sich heute jedoch eine Vielzahl von Restaurants, die Bezug nehmen auf das Judentum und seine kulinarischen Traditionen. Am Beispiel von fünf verschiedenen Städten (Berlin, Lodz, Paris, Wien, Zürich) wird aufgezeigt, wie „jüdische“ Gastronomie vor dem Hintergrund unterschiedlicher historischer Erfahrungen und vielfältiger Migrationsbewegungen von Juden aber auch von Nichtjuden neu interpretiert werden können. Auch wenn die meisten Gaststätten keine koscheren Speisen im religionsgesetzlichen Sinne anbieten, sind diese Restaurants doch ein wichtiges Merkmal eines innovativen und integrativen Umgangs mit Europas jüdischem Erbe.

Die frühe hebräische Geschichtsschreibung und die Historien Herodots - zwei Paar Stiefel?

In der Vergangenheit ist vielfach behauptet worden, dass die Hebräische Bibel und die Historien Herodots in ganz verschiedene literarische bzw. konzeptionelle Kategorien gehören. Ein Textvergleich soll klären, ob diese These haltbar ist. Der Tagungsbeitrag gibt Einblick in grundsätzliche Überlegungen im Zuge der Präzisierung des methodischen Zugriffs und der Fragestellung. Es werden zunächst kurz verschiedene Begründungen für die Verneinung von Historiographie im Tanach beleuchtet (Christian Meier, Erhard Blum, Philip Davies) und dann kurz die Schwierigkeiten bei der Definition von antiker Geschichtsschreibung dargestellt, die im Ergebnis für das Offenhalten von Kategorien- und Genregrenzen sprechen. Möglicherweise kann beim Umgang mit dieser etwas diffusen Situation die Kategorienbildung in der Prototypensemantik helfen. Ausgehend von einer Liste von Elementen, die nicht als ‚KO-Kriterien‘ für antike Geschichtsschreibung in Frage kommen wird kurz erläutert, warum Geschichtsschreibung und mythisches Erzählen in frühen historiographischen Texten miteinander kompatibel sind. Kurze Beispiele zeigen, dass Herodots Verhältnis zu mythischen und religiösen Vorstellungen keineswegs einheitlich ist, und dass diese Tradition einen der Bezugsrahmen seines Werks ausmacht. Diese Einsichten schlagen sich in den methodischen Überlegungen nieder. Ein wichtiger Ausgangspunkt ist hier die Annahme der Andersartigkeit der antiken Historiographie und ihrer Auffassung von der Arbeit und Aufgabe eines Historikers. In der Forschung sind zu meinem oder ähnlichen Themen verschiedene methodische Ansätze gewählt worden; so das Ausgehen von modernen oder antiken Geschichts- bzw. Literaturtheorien oder die Rekonstruktion des Umgangs der Autoren mit ihren Quellen. Demgegenüber bietet eine literaturwissenschaftlich-vergleichende Erzähltextanalyse gewisse Vorteile. Damit die Auswahl der Vergleichshinsichten nicht willkürlich erfolgt, brauchen komparatistische Textanalysen trotzdem ein theoretisches Konzept oder zumindest einen übergeordneten Leitgedanken. Hier scheint mir das Herausarbeiten der jeweils spezifischen ‚historischen Wahrheit‘ der Texte fruchtbar zu sein.

Cerebellar cortex involvement in classical eyelid conditioning

A model for cerebellar involvement in motor learning was tested using classical eyelid conditioning in the rabbit. Briefly, we assume that modifications of the strength of granule cell synapses at Purkinje cells in the cerebellar cortex and mossy fiber (MF) synapses at cerebellar interpositus nuclei are responsible for the acquisition, adaptively-timed expression, and extinction of conditioned eyelid responses (CRs). A corollary of these assumptions is that the cerebellar cortex is necessary for acquisition and extinction. This model also suggests a mechanism whereby the cerebellar cortex can discriminate different times during a conditioned stimulus (CS) and thus mediate the learned timing of CRs. Therefore, experiments were done to determine the role of the cerebellar cortex in the timing, extinction, and acquisition of CRs. Lesions of the cerebellar cortex that included the anterior lobe disrupted the learned timing of CRs such that they occurred at extremely short latencies. Stimulation of MFs in the middle cerebellar peduncle as the CS could support differently timed CRs in the same animal. These data indicate that synaptic plasticity in the cerebellar cortex mediates the learned timing of CRs. These short-latency CRs which resulted from anterior lobe damage did not extinguish, while CRs in animals receiving lesions which did not include the anterior lobe extinguished normally. Preliminary data suggests that lesions of the anterior lobe which produce short-latency responses prevent the acquisition of CRs to a novel CS. These findings indicate that the anterior lobe of cerebellar cortex is necessary for eyelid conditioning. The involvement of the anterior lobe in eyelid conditioning has not been previously reported, however, the anterior lobe has generally been spared in lesion studies examining cerebellar cortex involvement in eyelid conditioning due to its relatively inaccessible location. The observation that the anterior lobe of the cerebellar cortex is not always required for the basic expression of CRs, but is necessary for response timing, extinction, and acquisition, is consistent with the hypothesis that eyelid conditioning can involve plasticity in both the cerebellar cortex and interpositus nucleus and that plasticity in the nucleus is controlled by Purkinje cell activity. ^

The Social Imaginary of Culture/Civilization in the Arabic Literary Tradition

Charles Taylor’s contribution to social imaginaries offers an interpretive framework for better understanding modernity as secularity. One of its main aspects is conceiving of human society in linear, homogenous time (secular time). Looking into the Arabic intellectual tradition, I will argue in my paper that Taylor’s framework can help us understand major social and intellectual transformations. The Ottoman and Arabic modernization process during the 19th century has often been understood by focusing on certain core concepts. One of these is tamaddun, usually translated as “civilization.” I will be mostly talking about the works of two “pioneers” of Arab modernity (which is traditionally referred to as an-nahḍa, the so-called Arab Renaissance): the Syrian Fransīs Marrāsh and the Egyptian Rifāʿa aṭ-Ṭahṭāwī. First I will focus on Marrāsh’s didactic novel “The Forest of Truth” (1865), as it offers a complex view of tamaddun, which has sometimes been construed as merely a social and political reform program. The category of "social imaginary,” however, is useful in grasping the wider semantic scope of this concept, which is reading it as a signifier for human history conceived of in secular time, as Taylor defines it. This conceptualization of human history functioning within the immanent frame can also be observed in the introduction to “The Extraction of Pure Gold in the Description of Paris” (1834), a systematic account of a travel experience in France that was written by the other “pioneer,” aṭ-Ṭahṭāwī. Finally, in translating tamaddun as “the modern social imaginary of civilization/culture,” the talk aims to consider this imaginary as a major factor in the emergence of the “secular age.” Furthermore, it suggests the importance of studying (quasi-) literary texts, such as historiographical, geographical, and self-narratives in the Arabic literary tradition, in order to further elaborate continuities and ruptures in social imaginaries.