\documentclass[11pt]{article} \usepackage{amsfonts,amsbsy, amssymb, graphicx} % Tree-saver \setlength{\textwidth}{8.276in} \setlength{\textheight}{11.705in} %Allow 1in margin on each side and nothing else \addtolength{\textwidth}{-2in} \addtolength{\textheight}{-2in} \setlength{\oddsidemargin}{0pt} \setlength{\evensidemargin}{\oddsidemargin} \setlength{\topmargin}{0pt} \addtolength{\topmargin}{-\headheight} \addtolength{\topmargin}{-\headsep} \input mfpic.tex \renewcommand{\baselinestretch}{1.3} \renewcommand{\mathrm}[1]{{\mbox{\tiny #1}}} \newcommand{\dfrac}[2]{\displaystyle{\frac{#1}{#2}}} \newcommand{\ds}[1]{\displaystyle#1} \newcommand{\bs}[0]{\boldsymbol} \parindent=0pt \parskip=5pt \title{\LARGE\bf A new compartmental model - increased accuracy and precision of the traditional compartmental model without increased computational effort} \author{\Large\bf K.A. Lindsay\\ Department of Mathematics, University of Glasgow,\\ Glasgow G12 8QQ \\[10pt] \Large\bf A.E. Lindsay\\ Department of Mathematics, University of Edinburgh,\\ Edinburgh EH9 3JZ \\[10pt] \Large\bf J.R. Rosenberg$^\dagger$\\ Division of Neuroscience and Biomedical Systems,\\ University of Glasgow, Glasgow G12 8QQ} \makeatletter \def\@cite#1#2{{#1\if@tempswa , #2\fi}} \def\@biblabel#1{ } %\def\@biblabel#1{#1.} \makeatother \begin{document} \opengraphsfile{mfpic} \maketitle \thispagestyle{empty} \vfil \begin{tabular}{ll} $^\dagger$ & \textbf{Corresponding author} \\[5pt] & J.R. Rosenberg \\ & West Medical Building \\ & Division of Neuroscience and Biomedical Systems \\ & University of Glasgow \\ & Glasgow G12 8QQ \\ & Scotland UK \\[5pt] & Tel\quad(+44) 141 330 6589 \\ & Fax\quad(+44) 141 330 2923 \\ & Email \verb$j.rosenberg@bio.gla.ac.uk$\\[10pt] & \textbf{Keywords} \\[5pt] & Compartmental models, Dendrites, Cable Equation \end{tabular} \vfil \pagebreak[4] \begin{center} \begin{tabular}{p{5.2in}} \multicolumn{1}{c}{\textbf{Abstract}}\\[10pt] Compartmental models of dendrites are the most widely used tool for investigating their electrical behaviour. Traditional compartmental models assign a single potential to a compartment and consequently treat segments as iso-potential regions of dendrite. All input is assigned to the centre of a segment independent of its location on the segment. By contrast, the compartmental model introduced in this article assigns a potential to each end of a segment, and takes into account the effect of input location on model solution by partitioning input between the axial currents at the proximal and distal boundaries of segments. For a given number of segments, the new and traditional compartmental models use the same number of locations at which the membrane potential is to be found. However, the solution achieved by the new compartmental model gives an order of magnitude better accuracy and precision than that achieved by a traditional model. \end{tabular} \end{center} %\tableofcontents \pagebreak[4] \input NewComp1.tex \input NewComp2.tex \input NewComp3.tex \input NewComp4.tex \input NewComp5.tex \input NewComp6.tex \closegraphsfile \end{document} \begin{table}[!h] \[ \begin{array}{c|cccccccccccc} \hline \mbox{No. Compartments} & 34 & 41 & 54 & 61 & 75 & 82 & 93 & 193 & 293 & 390 & 495 & 992 \\ \log_{10}(\mbox{Compartments}) & 1.53 & 1.61 & 1.73 & 1.79 & 1.88 & 1.91 & 1.97 & 2.29 & 2.47 & 2.59 & 2.70 & 3.00 \\ \mbox{\begin{tabular}{c} Traditional Model \\[-5pt] Mean Firing Rate \end{tabular}} & 31.5 & 30.3 & 30.5 & 29.8 & 29.2 & 28.5 & 28.3 & 26.5 & 25.9 & 26.2 & 26.7 & 26.0 \\ \mbox{\begin{tabular}{c} New Model \\[-5pt] Mean Firing Rate \end{tabular}} & 27.6 & 27.9 & 27.5 & 27.2 & 27.0 & 27.0 & 26.8 & 26.5 & 26.2 & 26.2 & 26.2 & 26.1 \\ \hline \end{array} \] \centering \parbox{5.5in}{\caption{\label{simex2} The result of the second simulation exercise for a traditional compartmental model and the new compartmental model in which 10 second records of spike train activity are obtained for both models at various numbers of compartments.}} \end{table} \begin{center} \begin{tabular}{p{5.2in}} \multicolumn{1}{c}{\textbf{Abstract}}\\[10pt] Compartmental models of dendrites are the most widely used tool for investigating their electrical behaviour. Traditional compartmental models assign a single potential to a compartment. The value of this potential is taken to represent the potential at the centre of the segment represented by the compartment, and consequently the segment is treated as an iso-potential region of dendrite. In this model all input to a segment is assigned to the centre of the segment on which it acts, independent of its location on the segment. By contrast, the compartmental model introduced in this article assigns two potentials to a compartment -- one at each end of the segment represented by the compartment. The new model takes into account the effect of input location on model solution by partitioning the input between the axial currents at the proximal and distal boundaries of segments. For a given number of segments, the new and traditional compartmental models use the same number of locations at which the membrane potential is to be found. However, the solution achieved by the new compartmental model gives an order of magnitude better accuracy and precision than that achieved by a traditional model. \end{tabular} \end{center}