Neuron Reconstruction

What is Neuron Reconstruction and Why is it so Important?

Neuron reconstruction is the process of creating digital reconstructions of the entire (or sometimes only specific portions) of neurons. Neuron reconstruction includes delineating and reconstructing the axon, dendrites soma, and other sub-cellular components of a neuron, thereby creating a digital, geometric model of the neuron. Researchers use neuron reconstruction techniques for reconstruction and morphological analysis of neurons in tissue sections, tissue slabs, intact brains, and cell culture. Neuron reconstruction is typically performed using light microscopy imaging, sometimes it is performed using electron microscopy imaging. 

The resulting 3D reconstructions are used to visualize and analyze not only overall neuronal process length, but also other morphological quantities such as branching frequency, segment length, branch angle, spine or receptor density, and segment diameter. These digital reconstructions can be morphometrically analyzed to understand more about intricate neuronal structures. The reconstructions can also be used with electrotonic modeling software to model the electrical properties of neurons. The morphological structure and connectivity of somas, dendrites, axons, spines, varicosities and synapses provide extremely valuable information on the workings of neurons throughout the body, ranging from brain circuits to the peripheral nervous system.

Santiago Ramón y Cajal, was the first to perform neuron reconstruction. He did so with a pencil and paper, creating graphic representations of neurons he observed. Edmund Glaser, MBF Bioscience co-founder, and Hendrick van der Loos performed the first digital neuron reconstruction in the early 1960’s. Today, neuron reconstruction in performed in 1000’s of laboratories around the world using techniques that range from computer assisted, to fully-automatic. 

How Do You Reconstruct Neurons?

There are two general methods for reconstructing neurons. One popular method is to obtain images (2D or 3D) from a microscope and then use software that can import the image data and provide you with a set of tracing and segmentation tools. Some software may also have some built-in analyses tools. 

 Three important factors with this method are:

1.    Image data quality: The XY and Z resolution are very important as well as high contrast and low noise in the images

2.    Neuron reconstruction tools:  These tools can vary substantially from very basic drawing tools that come in free software to highly specialized tools that are designed specifically to reconstruct as accurate and detailed digital model of the neuron as possible

3.    Analyses tools: These tools can also very substantially from very basic measurement tools to highly sophisticated tools designed specifically to provide quantitative morphometric data that are relevant to neuroscience researchers 

A second popular method for reconstructing neurons does not require any previously acquired image data at all. This method requires a computer-controlled microscope-based system with software that provides neuron reconstruction tools to trace from a live camera image. This method is very popular for reconstructing Golgi stained neurons or other brightfield staining methods as there is no concern for tissue bleaching.

Three important factors with this method are:

1.    The software used must be capable of fully-controlling all motorized functions of the microscope to create one fully integrated system and the motorized stage must be off a high enough resolution in order to record accurate XYZ position data

2.    The software must include neuron reconstruction tools that allow the user to trace over a live camera image and across multiple fields of view and even multiple tissue sections

3.    The software must provide similar tools for image analysis that would be used in the first method.

What Makes Some Neuron Reconstructing Software Better Than Others?

• Accuracy and validity of the reconstruction produced
• Ease of use
• Speed of tracing and reconstruction
• Ability to detect, trace and reconstruct sub-cellular structures
• Automatic trading modes
  • Fully Automatic
  • User Guided
  • Manual
• Ability to handle big image data files
• Ability to handle multiple neurons
• Availability of technical support
• Built-in morphometric analyses tools
• Built-in tools for publishing data

What is the Best Neuron Reconstructing Software? 

Neurolucida and Neurolucida 360 are two different software applications that provide tools for 2D and 3D tracing dendrite, axons, spines, synapses, somas and varicosities. You can also use them to manually map the brain to give anatomical context to neuronal pathways, cells and synaptic distribution (for automatic brain nuclei mapping see NeuroInfo). 

Neurolucida is primarily a manual computer-assisted neuron reconstruction system that can be integrated directly with microscopes. In addition to reconstructing structures, it can be used as your primary image acquisition software package so you can do brightfield and multichannel fluorescent stack imaging, multifocal tiling, image post-processing. Neurolucida is the most widely used neuron reconstruction system in the world due to its ability to accurately trace virtually any neuron in any specimen. It is the gold standard in neuron reconstruction.

Neurolucida 360 is designed for automatic 3D and 2D reconstruction from acquired images from brightfield, fluorescence, confocal, and light sheet microscopes. Using multiple algorithms and a 3D interactive reconstruction environment, it can easily detect and trace structures automatically. It is compatible with different image modalities (confocal, 2-photon, lightsheet) and many proprietary image formats (.czi, .lif, .oib, .nd2, etc.). Neurolucida 360 is the most advanced automatic neuron reconstructing software. It can be used on 2D and 3D images obtained from a wide variety of specimens. Its capabilities for reconstructing neurons and modeling dendritic spines are unparalleled.