The locust standard brain: a 3D standard of the central complex as a platform for neural network analysis

El Jundi B(1), Heinze S, Lenschow C, Kurylas A, Rohlfing T, Homberg U.

Author information:
(1)Fachbereich Biologie, Tierphysiologie, Philipps-Universität Marburg Marburg,
Germany.

Many insects use the pattern of polarized light in the sky for spatial
orientation and navigation. We have investigated the polarization vision system
in the desert locust. To create a common platform for anatomical studies on
polarization vision pathways, Kurylas et al. (2008) have generated a
three-dimensional (3D) standard brain from confocal microscopy image stacks of
10 male brains, using two different standardization methods, the Iterative Shape
Averaging (ISA) procedure and the Virtual Insect Brain (VIB) protocol.
Comparison of both standardization methods showed that the VIB standard is ideal
for comparative volume analysis of neuropils, whereas the ISA standard is the
method of choice to analyze the morphology and connectivity of neurons. The
central complex is a key processing stage for polarization information in the
locust brain. To investigate neuronal connections between diverse
central-complex neurons, we generated a higher-resolution standard atlas of the
central complex and surrounding areas, using the ISA method based on brain
sections from 20 individual central complexes. To explore the usefulness of this
atlas, two central-complex neurons, a polarization-sensitive columnar neuron
(type CPU1a) and a tangential neuron that is activated during flight, the giant
fan-shaped (GFS) neuron, were reconstructed 3D from brain sections. To examine
whether the GFS neuron is a candidate to contribute to synaptic input to the
CPU1a neuron, we registered both neurons into the standardized central complex.
Visualization of both neurons revealed a potential connection of the CPU1a and
GFS neurons in layer II of the upper division of the central body.

DOI: 10.3389/neuro.06.021.2009
PMCID: PMC2818101
PMID: 20161763

Auteurs Bordeaux Neurocampus