A versatile and affordable array tomography workflow
FENS 2026: W01 Expanding Horizons: Array Tomography in Neuroscience for All
Fira Gran Via Barcelona (6-10 July 2026)
Ciliated zooplankton larvae
Volume EM with Array Tomograpy
Volume EM with Array Tomograpy
Fixation and screening of specimens
- High-pressure freezing + freeze substitution
- screening of samples by syncrotron X-ray
- Hamburg Desy Petra III and ESRF Grenoble I16A
Array tomography workflow
Array tomography workflow
Volume EM with Array Tomograpy
Sample mounting
- Leica UC7 Ultramicrotome
- ribbon pickup on ITO slides
- 2 Zeiss Gemin SEMs
- SensBSD detector
Array tomography workflow
Whole-body three-segmented Platynereis larva
- Platynereis dumerilii three-segmented larva
- whole-body connectome
- ~2,000 neurons
- 202 neuronal and 92 non-neuronal cell types
The non-bilaterian Metazoa
Ctenophores
Ernst Haeckel, Kunstformen der Natur (1904), plate 27: Ctenophorae
Balancer organ
- balancer organ = statocyst in the aboral organ
- stone cells = statolyths are balanced on four bundles of cilia
- change in orientation -> differential load on balancer cilia -> frequency change
- balancer beat-frequency propagates to comb rows
Balancer cilia respond to statocyst load
vEM of the ctenophore gravisensory organ
Kei Jokura
Ciliary bundles of the balancer supporting the statolyth
One large and two small nerve nets
- balancers SSN_Q12 SSN_Q34 SSN_Q1-4
Ctenophore synapses are unique
Connectome of the ctenophore balancer
- three syncytial nerve-net neurons
- nerve-net synapses on balancer cells
- no synapses from balancer to nerve net
- nerve nets synapse on each other
- not an input-output organisation
- nerve net coordinates the sensory-motor balancers
Synchronisation of balancer cilia
Connectome of the ctenophore balancer
- global coordination of balancer cells
- synchronisation of arrests (2x2 bundles)
- synchronisation of re-beat (all 4 bundles)
Going back to TEM…
- TurboTEM Horizon for Volume EM
- to be installed on a JEOL 120i
- new pole piece
- 100 mm wafer moved inside column
- high-throughput processing (50 to 300+ grids)
- custom grids slotted in wafer
Acknowledgements
- Alexandra Kerbl
- Karel Mocaer
- Sanja Jasek
- David Hug
- Jules Duruz
- Mateusz Kostecki
- Benedikt Dürr
- Kata Szabó
- Emily Savage
- Simone Wolters
- Anja Ciprianidis
- Kevin Urbansky
Alumni
- Kei Jokura (NIBB, Okazaki)
- Luis Bezares (LBDV, Villefranche-sur-mer)
- Luis Yanez-Guerra (Uni Sussex)
- Emelie Brodrick (Sussex)
- Csaba Verasztó (EPFL)
Facilities
- Réza Shahidi
- Charlotta Funaya
- Ulrike Engel
