Biology subjects

Frantzmann, F.

Publications and source records attributed to Frantzmann, F..

3 recordsLinked to original sources

bioRxiv2023

Neuronal correlates of time integration into memories

The circadian clock affects a wide range of physiological processes. Of particular interest is the influence of the clock on memory performance, as circadian dysfunction is associated with age- and disease-related decline in memory. In various species it has been shown that memory performance is regulated by the circadian clock. However, the anatomical and functional connection of the circadian clock and memory neurons has not been described in detail so far. This study now identifies that Diuretic hormone 31 (DH31)-positive clock neurons of the DN1p cluster regulate memory performance. DH31, a functional homolog of the mammalian calcitonin gene-related peptide, plays a crucial role in this process as a clock communication signal. DH31 facilitates memory performance during the night via indirect signalling, while DH31 signals directly to the mushroom bodies restricting memory performance specifically in the evening. This pleiotropic action of DH31 suggests that the circadian clock confines memory performance to a physiological dynamic range.

neuroscience↗

bioRxiv2019

A novel thermal-visual place learning paradigm for honeybees

Honeybees have fascinating navigational skills and learning capabilities in the field. To decipher the mechanisms underlying place learning in honeybees, we need paradigms to study place learning of individual honeybees under controlled laboratory conditions. Here, we present a novel visual place learning arena for honeybees which relies on high temperatures as aversive stimuli. Honeybees learn to locate a safe spot in an unpleasantly warm arena, relying on a visual panorama. Bees can solve this task very well at a temperature of 46{degrees}C, while at temperatures above 48 {degrees}C bees die quickly. This new paradigm, which is based on a pioneering work in Drosophila, allows us now to investigate thermal-visual place learning of individual honeybees in the laboratory, for example after controlled genetic knockout or pharmacological intervention.

neuroscience↗

bioRxiv2018

A comprehensive anatomical map of the peripheral octopaminergic/tyraminergic system of Drosophila melanogaster

The modulation of an animals behavior through external sensory stimuli, previous experience and its internal state is crucial to survive in a constantly changing environment. In most insects, octopamine (OA) and its precursor tyramine (TA) modulate a variety of physiological processes and behaviors by shifting the organism from a relaxed or dormant condition to a responsive, excited and alerted state. Even though OA/TA neurons of the central brain are described on single cell level in Drosophila melanogaster, the periphery was largely omitted from anatomical studies. Given that OA/TA is involved in behaviors like feeding, flying and locomotion, which highly depend on a variety of peripheral organs, it is necessary to study the peripheral connections of these neurons to get a complete picture of the OA/TA circuitry. We here describe the anatomy of this aminergic system in relation to peripheral tissues of the entire fly. OA/TA neurons arborize onto skeletal muscles all over the body and innervate reproductive organs, the heart, the corpora allata, and sensory neurons in the antenna, wings and halteres underlining their relevance in modulating complex behaviors.

neuroscience↗