Xanat 2.0

A Graphical Anatomical Database

By Bill Press and Bruno Olshausen

XANAT is a computer program that facilitates the analysis of neuroanatomical data by storing the results of numerous tracer studies in a standardized format, and by providing various tools for performing summaries and comparisons of these studies. Data are entered by drawing injection and label sites directly onto canonical representations of the neuroanatomical structures of interest, along with providing descriptive text information (shown above). Searches may then be performed on the data by querying the database graphically according to injection or label site, or via text information (i.e., keyword search). Analyses may also be performed by accumulating data across multiple studies and displaying a color coded map that graphically represents the total evidence for connectivity between regions. Thus, data may be studied and compared free of areal boundaries (which often vary from one lab to the next), and instead with respect to standard landmarks, such as the position relative to well known neuroanatomical substrates, or stereotaxic coordinates. If desired, areal boundaries may be defined by the user to facilitate the interpretation of results.

Shown at left is the result of an analysis performed on pulvinar-cortical connectivity data. The database was queried for all connections to and from the inferotemporal complex. The results are displayed as a color-coded heatmap superimposed on an area of interest, which in this case is a caudal slice of the pulvinar. Red denotes the highest evidence of connectivity, and blue the lowest. In this slice, regions of highest connectivity are found in the ventro-medial subdivision of the pulvinar. This result represents the cumulative evidence from 30 relevant studies culled from the database. (A total of 127 studies have been entered to date.)

XANAT was written in C to work under the X windows system (hence the name) in the unix operating system environment. We hope to make a version for Mac/PC platforms in the future.

Included with the distribution is an example dataset of pulvinar-cortical connectivity, which should prove useful in learning how to use the program.

Download the tar file: xanat-2.0.tar.Z or try out the interactive.