******************************************************* *** Simulator for Models of Neurite Outgrowth *** ******************************************************* Help Contents: 1. Author Details 2. System Requirements 3. Quick User Guide 4. Model Descriptions 5. References ----------------------------------------- 1. Author Details: ----------------------------------------- Author: Bruce P. Graham, Department of Computing Science and Mathematics, University of Stirling, Scotland, U.K. Email: b.graham@cs.stir.ac.uk Web: www.cs.stir.ac.uk/~bpg/ ----------------------------------------- 2. System Requirements: ----------------------------------------- Should run on any system supporting Java 2. Code provided as executable jar file (e.g. java -jar Neurite.jar). Example parameter files in "Params" subdirectory. ----------------------------------------- 3. Quick User Guide: ----------------------------------------- Button Function ------ -------- Quit quit the simulator Load load a set of simulation parameters Save save a set of simulation parameters Model select required model from drop-down menu and set model parameters Simulation set simulation parameters e.g. number of trees, simulation duration and time step Display set 2D visualisation parameters Off/On turn 2D visualisation off or on (visualisation only occurs during creation of a single tree) Plot turn on model parameter plotting (each selection creates new graph) Construct start simulator to create required number of trees (neurites) Stop terminate current simulation Draw draw 2D visualisation of one tree from currently created set of trees ("Display" must be on) Display tree index of tree visualised by "Draw" Help shows this file ----------------------------------------- 4. Model Descriptions: ----------------------------------------- The simulator currently contains three models of neurite outgrowth. 1. BESTL -------- This is an implementation of van Pelt's stochastic model of dendritic development, based on the description given in van Pelt and Uylings (1999). Example parameter files: BESTL_PC23.par - rat cortical layer 2/3 pyramidal cell basal dendrites (van Pelt et al, 2001) BESTL_PC5.par - rat corical layer 5 pyramidal cell basal dendrites (van Pelt & Uylings, 1999) BESTL_nonPC.par - rat cortical layer 4 non-pyramidal cell dendrites (van Pelt et al, 2003) BESTL_Pur.par - guinea pig Purkinje cell dendrites (van Pelt et al, 2001) 2. AD ----- Biophysical model of neurite outgrowth described in Graham and van Ooyen (2004). In the model, branching depends on the concentration of a branch-determining substance in each terminal segment. The substance is produced in the cell body and is transported by active transport and diffusion to the terminals. The model reveals that transport-limited effects may give rise to the same modulation of branching as indicated by the stochastic BESTL model. Different limitations arise if transport is dominated by active transport or by diffusion. Example parameter files for reproducing the same trees as for the BESTL model are provided (see Figure 4 and Table 2 of Graham & van Ooyen, 2004). Example parameter files: AD_PC23.par, AD_PC5.par, AD_nonPC.par, AD_Pur.par 3. ADcm ------- Implementation of the AD model in "compartmental" form, allowing calculation of spatial concentration profiles along the lengths of unbranched neurite segments. Compartmentalization follows "growth cone" scheme of Graham and van Ooyen (2001) in which a compartment immediately preceding a terminal (or "growth cone") compartment elongates as the neurite grows. All other compartments have fixed length. Elongating compartments are split into two when their length reaches twice the length of other compartments. A branching event results in a growth cone compartment being replaced by four new compartments, consisting of a new growth cone and one preceding compartment for the two new daughter branches. Concentration gradients are most obvious when transport is by slow diffusion. Example parameter file: ADcm_D600.par ----------------------------------------- 5. References: ----------------------------------------- Graham, B.P. & van Ooyen, A., Compartmental models of growing neurites, Neurocomputing 38-40:31-36, 2001 Graham, B.P. & van Ooyen, A., Transport limited effects in a model of dendritic branching, Journal of Theoretical Neurobiology 230:421-432, 2004 van Pelt, J. & Uylings, H.B.M., Natural variability in the geometry of dendritic branching patterns, Chapt. 4 in "Modeling in the Neurosciences: From Ionic Channels to Neural Networks", Poznanski, R.R. (ed.), Harwood Academic, pp79-108, 1999 van Pelt, J., van Ooyen, A. & Uylings, H.B.M.,, Modeling dendritic geometry and the development of nerve connections, Chapt. 7 in "Computational Neuroscience: Realistic Modeling for Experimentalists", De Schutter, E. (ed.), CRC Press, pp179-208, 2001 van Pelt, J., Graham, B.P. and Uylings, H.B.M., Formation of dendritic branching patterns, Chapt. 4 in "Modeling Neural Development", van Ooyen, A. (ed.), MIT Press, pp75-94, 2003.