TY  - JOUR
A1  - Fleischmann, Pauline N.
A1  - Grob, Robin
A1  - Rössler, Wolfgang
T1  - Magnetosensation during re-learning walks in desert ants (Cataglyphis nodus)
JF  - Journal of Comparative Physiology A
N2  - At the beginning of their foraging careers, Cataglyphis desert ants calibrate their compass systems and learn the visual panorama surrounding the nest entrance. For that, they perform well-structured initial learning walks. During rotational body movements (pirouettes), naïve ants (novices) gaze back to the nest entrance to memorize their way back to the nest. To align their gaze directions, they rely on the geomagnetic field as a compass cue. In contrast, experienced ants (foragers) use celestial compass cues for path integration during food search. If the panorama at the nest entrance is changed, foragers perform re-learning walks prior to heading out on new foraging excursions. Here, we show that initial learning walks and re-learning walks are structurally different. During re-learning walks, foragers circle around the nest entrance before leaving the nest area to search for food. During pirouettes, they do not gaze back to the nest entrance. In addition, foragers do not use the magnetic field as a compass cue to align their gaze directions during re-learning walk pirouettes. Nevertheless, magnetic alterations during re-learning walks under manipulated panoramic conditions induce changes in nest-directed views indicating that foragers are still magnetosensitive in a cue conflict situation.
KW  - path integration
KW  - landmark panorama
KW  - learning and memory
KW  - magnetic compass
KW  - navigation
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-266556
SN  - 1432-1351
VL  - 208
IS  - 1
ER  - 
TY  - JOUR
A1  - Grob, Robin
A1  - Tritscher, Clara
A1  - Grübel, Kornelia
A1  - Stigloher, Christian
A1  - Groh, Claudia
A1  - Fleischmann, Pauline N.
A1  - Rössler, Wolfgang
T1  - Johnston's organ and its central projections in Cataglyphis desert ants
JF  - Journal of Comparative Neurology
N2  - The Johnston's organ (JO) in the insect antenna is a multisensory organ involved in several navigational tasks including wind‐compass orientation, flight control, graviception, and, possibly, magnetoreception. Here we investigate the three dimensional anatomy of the JO and its neuronal projections into the brain of the desert ant Cataglyphis, a marvelous long‐distance navigator. The JO of C. nodus workers consists of 40 scolopidia comprising three sensory neurons each. The numbers of scolopidia slightly vary between different sexes (female/male) and castes (worker/queen). Individual scolopidia attach to the intersegmental membrane between pedicel and flagellum of the antenna and line up in a ring‐like organization. Three JO nerves project along the two antennal nerve branches into the brain. Anterograde double staining of the antennal afferents revealed that JO receptor neurons project to several distinct neuropils in the central brain. The T5 tract projects into the antennal mechanosensory and motor center (AMMC), while the T6 tract bypasses the AMMC via the saddle and forms collaterals terminating in the posterior slope (PS) (T6I), the ventral complex (T6II), and the ventrolateral protocerebrum (T6III). Double labeling of JO and ocellar afferents revealed that input from the JO and visual information from the ocelli converge in tight apposition in the PS. The general JO anatomy and its central projection patterns resemble situations in honeybees and Drosophila. The multisensory nature of the JO together with its projections to multisensory neuropils in the ant brain likely serves synchronization and calibration of different sensory modalities during the ontogeny of navigation in Cataglyphis.
KW  - ant brain
KW  - chordotonal organ
KW  - graviception
KW  - magnetic compass
KW  - multisensory integration
KW  - navigation
KW  - wind compass
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-225679
VL  - 529
IS  - 8
SP  - 2138
EP  - 2155
ER  -