A comparison of manual neuronal reconstruction from biocytin histology
or 2-photon imaging: morphometry and computer modeling
A. V. Blackman, S. Grabuschnig, R. Legenstein, and
P. J. Sjöström
Accurate 3D reconstruction of neurons is vital for applications linking anatomy
and physiology. Reconstructions are typically created using Neurolucida after
biocytin histology (BH). An alternative inexpensive and fast method is to use
freeware such as Neuromantic to reconstruct from fluorescence imaging (FI)
stacks acquired using 2-photon laser-scanning microscopy during physiological
recording. We compare these two methods with respect to morphometry, cell
classification, and multicompartmental modeling in the NEURON simulation
environment. Quantitative morphological analysis of the same cells
reconstructed using both methods reveals that whilst biocytin reconstructions
facilitate tracing of more distal collaterals, both methods are comparable in
representing the overall morphology: automated clustering of reconstructions
from both methods successfully separates neocortical basket cells from
pyramidal cells but not BH from FI reconstructions. BH reconstructions suffer
more from tissue shrinkage and compression artifacts than FI reconstructions
do. FI reconstructions, on the other hand, consistently have larger process
diameters. Consequently, significant differences in NEURON modeling of
excitatory post-synaptic potential (EPSP) forward propagation are seen
between the two methods, with FI reconstructions exhibiting smaller
depolarizations. Simulated action potential backpropagation (bAP), however,
is indistinguishable between reconstructions obtained with the two methods.
In our hands, BH reconstructions are necessary for NEURON modeling and
detailed morphological tracing, and thus remain state of the art, although
they are more labor intensive, more expensive, and suffer from a higher
failure rate due to the occasional poor outcome of histological processing.
However, for a subset of anatomical applications such as cell type
identification, FI reconstructions are superior, because of indistinguishable
classification performance with greater ease of use, essentially 100rate, and lower cost.
Reference: A. V. Blackman, S. Grabuschnig, R. Legenstein, and
P. J. Sjöström.
A comparison of manual neuronal reconstruction from biocytin histology or
2-photon imaging: morphometry and computer modeling.
Frontiers in neuroanatomy, 8, 2014.