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  - 
TY  - JOUR
A1  - Grob, Robin
A1  - Heinig, Niklas
A1  - Grübel, Kornelia
A1  - Rössler, Wolfgang
A1  - Fleischmann, Pauline N.
T1  - Sex-specific and caste-specific brain adaptations related to spatial orientation in Cataglyphis ants
JF  - Journal of Comparative Neurology
N2  - Cataglyphis desert ants are charismatic central place foragers. After long-ranging foraging trips, individual workers navigate back to their nest relying mostly on visual cues. The reproductive caste faces other orientation challenges, i.e. mate finding and colony foundation. Here we compare brain structures involved in spatial orientation of Cataglyphis nodus males, gynes, and foragers by quantifying relative neuropil volumes associated with two visual pathways, and numbers and volumes of antennal lobe (AL) olfactory glomeruli. Furthermore, we determined absolute numbers of synaptic complexes in visual and olfactory regions of the mushroom bodies (MB) and a major relay station of the sky-compass pathway to the central complex (CX). Both female castes possess enlarged brain centers for sensory integration, learning, and memory, reflected in voluminous MBs containing about twice the numbers of synaptic complexes compared with males. Overall, male brains are smaller compared with both female castes, but the relative volumes of the optic lobes and CX are enlarged indicating the importance of visual guidance during innate behaviors. Male ALs contain greatly enlarged glomeruli, presumably involved in sex-pheromone detection. Adaptations at both the neuropil and synaptic levels clearly reflect differences in sex-specific and caste-specific demands for sensory processing and behavioral plasticity underlying spatial orientation.
KW  - antennal lobe
KW  - synaptic plasticity
KW  - polymorphism
KW  - optic lobes
KW  - mushroom bodies
KW  - learning and memory
KW  - central complex
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-257299
VL  - 529
IS  - 18
ER  -