Leech Mechanosensory Neurons: Synaptic Facilitation by Reflected APs (Baccus 1998)

 Download zip file 
Help downloading and running models
Accession:3807
This model by Stephen Baccus explores the phenomena of action potential (AP) propagation at branch boints in axons. APs are sometimes transmitted down the efferent processes and sometimes are reflected back to the axon of AP origin or neither. See the paper for details. The model zip file contains a readme.txt which list introductory steps to follow to run the simulation. Stephen Baccus's email address: baccus@fas.harvard.edu
Reference:
1 . Baccus SA (1998) Synaptic facilitation by reflected action potentials: enhancement of transmission when nerve impulses reverse direction at axon branch points. Proc Natl Acad Sci U S A 95:8345-50 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Neuron or other electrically excitable cell;
Brain Region(s)/Organism:
Cell Type(s): Leech pressure (P) mechanosensory neuron;
Channel(s): I K; I K,Ca; I Sodium; I Calcium; I Potassium;
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Action Potential Initiation; Pattern Recognition; Activity Patterns; Spatio-temporal Activity Patterns; Influence of Dendritic Geometry; Detailed Neuronal Models; Synaptic Plasticity; Short-term Synaptic Plasticity; Axonal Action Potentials; Action Potentials; Facilitation; Invertebrate;
Implementer(s): Baccus, Stephen [Baccus at fas.Harvard.edu];
Search NeuronDB for information about:  I K; I K,Ca; I Sodium; I Calcium; I Potassium; 
This is an implementation of Stephen Baccus's original model from the paper
Baccus SA. Synaptic facilitation by reflected action potentials: 
enhancement of transmission when nerve impulses reverse direction 
at axon branch points. Proc Natl Acad Sci U S A. 1998 Jul 7;95(14):8345-50
with minor changes by Michael Hines and Tom Morse.

Stephen Baccus's email:
baccus@fas.harvard.edu

How to use:

First install the neuron simulator if you have not already:
http://www.neuron.yale.edu

To start the simulation:

On Macintosh computers:

   Download the zip file.
   Drag it onto the mos2nrn application icon.

On PC's or UNIX:

   Auto-launch the program from the model description page in modelDB.
   (or download, extract the zip file; compile with mknrndll;  Clicking on
   the mosinit.hoc file on the pc or typing nrngui mosinit.hoc under
   unix will start the simulation)

----------------------------------

Once the default simulation is started you can
1)click on the Voltage Space Plot and then
2)click on the Fig 6 button.

Action potentials are shown propagating down the stimulated
axon and then occasionally reflecting back down this stimulated
axon and also propagating into the thick axon and the thin posterior
axon.  See paper for details. Note that the AP's travel faster in 
thicker axons than thiner axons.

If you wish to slow down the simulation 
3) click on high resolution (after stopping the model from the
   run control page if it is not already stopped)
4) click on the Fig 6 button to start again.

20110411 changed solve method to cnexp in caacum.mod and naacum.mod as
per "Integration methods for SOLVE statements" topic in the NEURON
forum http://www.neuron.yale.edu/phpBB/viewtopic.php?f=28&t=592
20110412 corrected above change to derivimplicit from cnexp
-ModelDB Administrator

Loading data, please wait...