Model of a Sympathetic Preganglionic Neurone
Created by M.F. Nolan 2010
Edited by L.J.B Briant

1. This code creates a model of a sympathetic preganglionic neurone
(SPN), which is used in Briant and Stalbovskiy et al. (2014). The code
describing the morphology and mechanisms in the model cell are in
Cell.hoc.

2. The model focuses on ensuring the potassium A-current (IA) within
the model, and the output produced by the model in response to typical
inputs, well-fits the experimental data (see Figure 2 in Whyment et
al. 2011).

These parameter fitting data are generated by:

I-V.hoc 				
CurrentMagnitude.hoc
HyperpolarisingPulses.hoc
I-F.hoc					
PrepulseDuration.hoc
Activation.hoc
Inactivation.hoc

These simulation generate data for Figure A1 in Briant and Stalbovskiy
et al. (2014). The steady-state curve (Figure A1 A3) can be generated
from the output of these hoc codes, by using the MATLAB code provided
in the MATLAB code folder.

3. The model is then used to investigate how alterations to IA
influence the excitability and output of the model. The reader can
alter IA parameters and measure how the excitability (say AHP)
changes. As an example parameter GKABAR is investigated for its
influence on the inflection point in GKABAR_Inflection.hoc (Figure 5
in Briant and Stalbovskiy et al. (2014)).

4. The influence of other IA parameters on the excitability and output
of the model can be implemented by the reader by injecting a small,
large amplitude current pulse (2ms, 2nA) and using the MATLAB code to
measure AHP duration, amplitude etc.

References:

Whyment AD, Coderre E, Wilson JM, Renaud LP, O'Hare E, and Spanswick
D.  Electrophysiological, pharmacological and molecular profile of the
transiently outward rectifying conductance in rat sympathetic
preganglionic neurons in vitro.  Neuroscience 178: 68-81, 2011.

Briant, L. J.  and Stalbovskiy, A. O.  and Nolan, M. F.  and
Champneys, A. R.  and Pickering, A. E.  Increased intrinsic
excitability of muscle vasoconstrictor preganglionic neurons may
contribute to the elevated sympathetic activity in hypertensive rats
J. Neurophysiol. Aug 2014