; VisSim Block Diagram Format (VBDF) ; Copyright (C) 1989-1995 Visual Solutions POa="Terry Dwyer" PV=2.000 PS=0 PE=3 PP=0.01 PI=172 PX=0.01 PN=1e-006 PL=5 PT=1e-005 Pn=-12,6,20,"Times New Roman" Pc=393 Po=1,50,666 Ppl=1 Ppp=0 Ppt=0 Ppf=1 Pe=0 PD=1024x768 Pf=0x0 Pr="stub" Ps=995,0,0,680,0,0 Pd=17 PM=1,1,1,1 N.1="date"*117x81 N.2="label"*73x1 n="Bibliography" N.3="comment"*8x4*105x47 C=" The definitive reference is Hodgkin, A. L. and A. F. Huxley. (1952) A quantitative description of membrane current and its application to conduction and excitation in nerve. J. Physiol. 117: 500-544. The contemporary classic is Hille, Bertil. Ion Channels of Excitable Membranes. (1984) " N.4="label"*115x83 n="Hodgkin-Huxley Action Potential" N.5="label"*153x83 n="Version 2.0" N.6="Compound"*142x86 n="Graph" Ms=1993,0,0,1360,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.7="label"*78x0 n="Graph" N.8="Compound"*45x76 n="Membrane Current" Ms=1993,0,0,1360,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.9="label"*56x1 n="Membrane Current" N.10="Compound"*110x9 n="Membrane Notes" Ms=1993,0,0,1360,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.11="label"*68x1 n="Membrane Notes" N.12="comment"*8x4*105x47 C=" Membrane potential is a function of the charge separation across the membrane and membrane capactance. Charge separation is the integral over time of current flowing through the membrane. Current is the sum of sodium (I Na+), potassium (I K+) and leak (I Leak) currents. The step function simulates a current pulse that moves the membrane charge to a new level. End " N.13="variable"*134x30 n="I" N.14="display"(-0.94026784442519)*128x22 Oe=6 Ox=1 Ov=0 N.15="summingJunction"*97x27#4,1 N.16="wirePositioner"*80x17 N.17="variable"*14x17 n="I_Na+" N.18="display"(-102.62817891676)*41x9 Oe=6 Ox=1 Ov=0 N.19="wirePositioner"*79x29 N.20="variable"*15x29 n="I_K+" N.21="display"(470.24524030836)*41x22 Oe=6 Ox=1 Ov=0 N.22="wirePositioner"*80x44 N.23="variable"*12x44 n="I_Leak" N.24="display"(6.4426707639776)*41x36 Oe=6 Ox=1 Ov=0 N.25="label"*46x12 n="uA / cm^2" N.26="label"*46x25 n="uA / cm^2" N.27="label"*46x40 n="uA / cm^2" N.28="Compound"*103x89 n="Units" Ms=1993,0,0,1360,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.29="label"*73x1 n="Units" N.30="comment"*8x4*105x47 C=" Physical units in this model are Voltage mv Current uA / cm^2 Charge uC / cm^2 Conductance (uA / cm^2) / mv Capacitance mv / (uC / cm^2) Time msec End " N.31="plot"*0x4*71x39#1,0 pt="Membrane Potential" px="Time (msec)" pax=0 pf=H pf=F pb=40,-100 pbx=3,0 pbY=0,0 pbX=0,0 pc=512 pm=10,0 pb.0=100,-200 pb.1=0,0 pb.2=0,0 pb.3=0,0 N.32="plot"*0x44*71x15#2,0 pt="Conductances" px="time (ms)" pax=0 pf=H pf=F pb=30,0 pbx=3,0 pbY=0,0 pbX=0,0 pc=512 pm=10,0 pg=0,3pb.0=0,0 pb.1=30,0 pb.2=0,0 pb.3=0,0 N.33="variable"*4x1 n="V" N.34="variable"*0x60 n="G_Na+" N.35="variable"*16x60 n="G_K+" N.36="Compound"*56x86 n="K+ Current" Ms=1993,0,0,1360,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.37="label"*67x1 n="K+ Current" N.38="variable"*143x12 n="I_K+" N.39="display"(470.24524030836)*139x14 Oe=6 Ox=1 Ov=0 N.40="label"*142x16 n="uA / cm^2" N.41="*"*128x11 N.42="Compound"*56x88 n="Leak Current" Ms=1993,0,0,1360,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.43="label"*45x4 n="Leak Current" N.44="Compound"*12x4 n="Current Notes" Ms=371,0,0,48,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.45="label"*62x1 n="Membrane Notes" N.46="comment"*8x4*105x47 C=" Each ion current is a function of membrane potential, equilibration potential and ion conductance. Equilibration potentials are functions of intracellular and extracellular ion concentrations. These potential are parameters is this model. End " N.47="variable"*60x19 n="I_Leak" N.48="label"*36x29 n=" Leak Current's Equilibrium Potential" N.49="summingJunction"*86x35 N.50="wirePositioner"*51x37 N.51="variable"*81x20 n="G_Leak" N.52="display"(0.3)*74x17 Oe=6 Ox=1 Ov=0 N.53="variable"*62x35 n="V" N.54="display"(-50.281861310408)*74x32 Oe=6 Ox=1 Ov=0 N.55="label"*33x14 n="mv" N.56="*"*32x18 N.57="Compound"*17x89 n="Membrane Voltange" Ms=1993,0,0,1360,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.58="label"*60x1 n="Membrane Voltage" N.59="Compound"*11x2 n="Membrane Notes" Ms=409,0,0,48,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.60="label"*68x1 n="Membrane Notes" N.61="comment"*8x4*105x47 C=" Membrane potential is a function of the charge separation across the membrane and membrane capactance. Charge separation is the integral over time of current flowing through the membrane. Current is the sum of sodium (I Na+), potassium (I K+) and leak (I Leak) currents. The step function simulates a current pulse that moves the membrane charge to a new level. End " N.62="integrator"(50.24,0,0)*57x35 N.63="display"(50.281861310408)*73x29 Oe=6 Ox=1 Ov=0 N.64="variable"*84x35 n="Q" N.65="display"(50.281861310408)*92x32 Oe=6 Ox=1 Ov=0 N.66="variable"*24x35 n="I" N.67="display"(-0.94026784442519)*44x29 Oe=6 Ox=1 Ov=0 N.68="label"*77x31 n="mv" N.69="label"*49x33 n="uA / cm^2" N.70="label"*134x25 n="uA / cm^2" N.71="variable"*146x63 n="% Inactivation" N.72="variable"*124x63 n="% Activation" N.73="variable"*105x63 n="G_Na+" N.74="meter"(-100,100)*74x5*89x47#4,0 n="Sodium Channel Behavior" Tt=1 Tw=0,-1000,0,"Na Current" Tw=1,0,40,"Na Conductance" Tw=2,0,100,"% Activation" Tw=3,0,100,"% Inactivation" Tc=0,16777215 Tc=1,8421504 Tg=1,8 Tc=2,32768 Tc=3,255 Tl=16744448 TL=0 N.75="variable"*85x63 n="I_Na+" N.76="*"*106x41#4,1 N.77="label"*4x56 n="Off Rate: N Gate" Ob=16777215 Og=8421504 Of=-19,0,700,0,0,0,34,"Arial" N.78="summingJunction"*62x40 N.79="*"*54x48 N.80="const"(1)*91x31 N.81="summingJunction"*100x31 N.82="*"*49x29 N.83="variable"*93x41 n="N" N.84="integrator"(0.727,3,0)*72x41 N.85="variable"*70x41 n="tau_N" N.86="meter"(-100,100)*88x35*19x14 n="tau_N" Tt=1 Tw=0,0,6,"Rate" Tc=0,255 N.87="1/X"*72x46 N.88="summingJunction"*63x45 N.89="const"(-1)*39x24 N.90="summingJunction"*47x24 N.91="/"*62x16 N.92="exp"*33x26 N.93="const"(10)*29x19 N.94="variable"*51x8 n="alpha_N" N.95="summingJunction"*24x13 N.96="const"(10.001)*9x13 N.97="/"*36x14 N.98="const"(8)*47x53 N.99="/"*36x49 N.100="const"(0.001)*5x50 N.101="summingJunction"*20x48 N.102="variable"*50x58 n="beta_N" N.103="const"(80)*25x53 N.104="exp"*44x50 N.105="variable"*4x13 n="H_H_V" N.106="label"*8x9 n="On Rate: N Gate" Ob=16777215 Og=8421504 Of=-19,0,700,0,0,0,34,"Arial" N.107="display"(0.83027282664697)*68x39 Oe=6 Ox=1 Ov=0 N.108="display"(11.271961191924)*94x10 Oe=6 Ox=1 Ov=0 N.109="meter"(-100,100)*62x19*72x31 n="Potassium Current" Tt=1 Tw=0,0,1000,"uA/cm^2" Tc=0,255 N.110="const"(36)*93x49 N.111="/"*55x50 N.112="variable"*11x12 n="H_H_V" N.113="display"(-29.718138689592)*27x12 Oe=6 Ox=1 Ov=0 N.114="display"(-69.4)*37x34 Oe=6 Ox=1 Ov=0 N.115="summingJunction"*26x36 N.116="variable"*4x35 n="H_H_Offset" N.117="const"(10.6)*13x38 N.118="const"(-12)*78x22 N.119="variable"*63x19 n="H_H_Offset" N.120="summingJunction"*88x19 N.121="display"(-92)*98x22 Oe=6 Ox=1 Ov=0 N.122="display"(-50.281861310408)*79x8 Oe=6 Ox=1 Ov=0 N.123="variable"*86x10 n="V" N.124="summingJunction"*104x10 N.125="label"*97x24 n="Potassium Current's Equilibrium Potential" N.126="display"(0.72660683201199)*72x39 Oe=6 Ox=1 Ov=0 N.127="display"(80)*65x17 Oe=6 Ox=1 Ov=0 N.128="display"(0.87506168915152)*52x6 Oe=6 Ox=1 Ov=0 N.129="display"(0.32936168579917)*51x56 Oe=6 Ox=1 Ov=0 N.130="/"*52x15 N.131="const"(10)*45x17 N.132="label"*63x51 n="uC / cm^2" N.133="display"(-375)*58x48 Oe=6 Ox=1 Ov=0 N.134="wirePositioner"*82x57 N.135="variable"*14x57 n="Stimulus" N.136="plot"*107x35*59x30#3,0 px="Time (sec)" pax=0 pf=H pf=F pb=100,-100 pbx=3,0 pbY=0,0 pbX=1,0 pc=512 pm=10,0 pb.0=0,-900 pb.1=900,0 pb.2=200,-100 pb.3=100,-400 N.137="variable"*95x39 n="I_Na+" N.138="variable"*95x49 n="I_K+" N.139="variable"*96x59 n="I" N.140="variable"*95x13 n="G_K+" N.141="plot"*16x28*92x24#1,0 px="Time (sec)" pax=0 pf=H pf=F pb=50,-100 pbx=3,0 pbY=0,0 pbX=0,0 pc=512 pm=10,0 pb.0=50,-90 pb.1=0,0 pb.2=0,0 pb.3=0,0 N.142="label"*131x38 n="mv" N.143="-X"*112x41 N.144="/"*91x40 N.145="label"*58x48 n="Capacitance (1.0 mv / (uC / cm^2))" N.146="slider"(1,10,0)*66x44 N.147="display"(-50.281861310408)*123x36 Oe=6 Ox=1 Ov=0 N.148="variable"*138x41 n="V" N.149="display"(-50.281861310408)*57x6 Oe=6 Ox=1 Ov=0 N.150="display"(-29.718138689592)*93x10 Oe=6 Ox=1 Ov=0 N.151="variable"*51x15 n="H_H_Offset" N.152="slider"(80,80,60)*30x15 N.153="variable"*94x14 n="H_H_V" N.154="variable"*62x11 n="V" N.155="summingJunction"*77x13 N.156="Compound"*147x81 n="Bibliography" Ms=0,0,0,0,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.157="plot"*47x0*57x22#1,0 pt="Membrane Potential" px="Time (msec)" py="mV" pax=0 pf=H pf=F pb=40,-100 pbx=3,0 pbY=0,0 pbX=0,0 pc=512 pm=10,0 pg=3,0pb.0=0,0 pb.1=0,0 pb.2=0,0 pb.3=0,0 N.158="variable"*39x10 n="V" N.159="wirePositioner"*96x27 N.160="variable"*52x10 n="RateTempEffect" N.161="*"*73x8 N.162="variable"*50x60 n="RateTempEffect" N.163="*"*73x58 N.164="wirePositioner"*70x49 N.165="display"(3.8202161018186)*88x31 Oe=6 Ox=1 Ov=0 N.166="const"(6.3)*29x35 N.167="const"(10)*49x36 N.168="const"(3)*67x33 N.169="summingJunction"*38x33 N.170="/"*56x34 N.171="Compound"*111x89 n="Temperature Effect" Ms=2048,0,0,3840,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.172="/"*57x14 N.173="summingJunction"*39x13 N.174="const"(1.1)*63x13 N.175="const"(10)*33x18 N.176="const"(6.3)*30x15 N.177="display"(1.1233085794566)*85x11 Oe=6 Ox=1 Ov=0 N.178="variable"*10x13 n="Temperature" N.179="variable"*11x33 n="Temperature" N.180="label"*65x30 n="Q10" N.181="label"*63x10 n="Q10" N.182="pow"(2)*72x13#2,1 N.183="pow"(2)*74x33#2,1 N.184="variable"*86x14 n="G_TempEffect" N.185="variable"*88x34 n="RateTempEffect" N.186="variable"*92x61 n="G_TempEffect" N.187="slider"(18.5,37,0)*33x3 N.188="variable"*61x3 n="Temperature" N.189="Compound"*20x19#1,2 n="beta_N" Ms=0,0,0,0,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.190="Compound"*23x12#2,0 n="tau_N" Ms=0,0,0,0,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.191="Compound"*20x6#1,1 n="alpha_N" Ms=0,0,0,0,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.192="*"*102x47#3,1 N.193="variable"*61x13 n="N_fourth" N.194="Compound"*45x12#2,1 n="N_fourth" Ms=2048,0,0,3840,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.195="Compound"*80x13#1,1 n="G_K+" Ms=0,0,0,0,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.196="Compound"*115x8#0,1 n="Driving_Force_K+" Ms=0,0,0,0,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.197="variable"*2x71 n="I_Na+" N.198="variable"*5x75 n="G_Na+" N.199="variable"*4x103 n="% Activation" N.200="variable"*4x107 n="% Inactivation" N.201="variable"*11x95 n="I_Na+" N.202="meter"(-100,100)*24x94*105x16#4,0 n="Sodium Channel Behavior" Tt=0 Tw=0,0,1,"Na Current (uA/cm^2)" Tw=1,0,1,"Na Conductance (mmho/cm^2)" Tw=2,0,1,"% Activation Gates Open" Tw=3,0,1,"% Inactivation Gates Closed" Tc=0,16777215 Tc=1,8421504 Tc=2,32768 Tc=3,255 Tl=0 TL=0 N.203="meter"(-100,100)*20x70*105x16#4,0 n="Sodium Channel Behavior" Tt=0 Tw=0,0,1,"Na Current (uA/cm^2)" Tw=1,0,1,"Na Conductance (mmho/cm^2)" Tw=2,0,1,"% Activation Gates Open" Tw=3,0,1,"% Inactivation Gates Closed" Tc=0,16777215 Tc=1,8421504 Tc=2,32768 Tc=3,255 Tl=0 TL=0 N.204="Compound"*153x28#0,1 n="Driving_Force_Na+" Ms=0,0,0,0,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.205="display"(80)*83x42 Oe=6 Ox=1 Ov=0 N.206="label"*122x50 n="Sodium's Current's Equilibrium Potential" N.207="summingJunction"*137x43 N.208="variable"*125x43 n="V" N.209="display"(-50.281861310408)*118x41 Oe=6 Ox=1 Ov=0 N.210="display"(35)*123x48 Oe=6 Ox=1 Ov=0 N.211="summingJunction"*112x44 N.212="variable"*83x44 n="H_H_Offset" N.213="const"(115)*103x46 N.214="Compound"*64x21#2,2 n="M_cubed" Ms=2048,0,0,3840,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.215="*"*71x51#3,1 N.216="*"*80x58 N.217="const"(100)*63x60 N.218="variable"*62x53 n="M" N.219="integrator"(0.6215,1,0)*38x53 N.220="*"*14x46 N.221="summingJunction"*48x47 N.222="const"(1)*42x47 N.223="*"*32x60 N.224="summingJunction"*22x47 N.225="wirePositioner"*54x43 N.226="wirePositioner"*55x53 N.227="wirePositioner"*88x62 N.228="Compound"*59x46#2,2 n="H" Ms=2048,0,0,3840,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.229="summingJunction"*60x45 N.230="*"*57x52 N.231="const"(1)*96x36 N.232="summingJunction"*103x36 N.233="*"*79x37 N.234="integrator"(0.0374,2,0)*69x46 N.235="*"*118x37 N.236="const"(100)*109x41 N.237="display"(0.037920622356809)*110x50 Oe=6 Ox=1 Ov=0 N.238="wirePositioner"*102x32 N.239="wirePositioner"*97x46 N.240="wirePositioner"*121x46 N.241="wirePositioner"*127x29 N.242="*"*113x26#3,1 N.243="variable"*112x23 n="G_TempEffect" N.244="*"*126x26 N.245="variable"*159x31 n="G_Na+" N.246="variable"*83x23 n="M_cubed" N.247="Compound"*39x46#2,0 n="tau_H" Ms=0,0,0,0,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.248="variable"*88x25 n="tau_H" N.249="meter"(-100,100)*102x26*19x11 n="tau_H" Tt=1 Tw=0,0,1,"Rate" Tc=0,255 N.250="1/X"*89x30 N.251="summingJunction"*80x29 N.252="display"(0.51109548975539)*83x23 Oe=6 Ox=1 Ov=0 N.253="Compound"*36x41#1,1 n="alpha_H" Ms=0,0,0,0,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.254="label"*21x8 n="On Rate: H Gate" Ob=16777215 Og=8421504 Of=-19,0,700,0,0,0,34,"Arial" N.255="exp"*59x13 N.256="const"(20)*43x16 N.257="variable"*56x7 n="alpha_H" N.258="summingJunction"*34x11 N.259="const"(0.001)*21x11 N.260="/"*53x12 N.261="const"(0.085)*60x17 N.262="*"*69x13 N.263="display"(0.073486470480953)*58x5 Oe=6 Ox=1 Ov=0 N.264="variable"*58x9 n="RateTempEffect" N.265="*"*82x7 N.266="Compound"*36x53#1,1 n="beta_H" Ms=0,0,0,0,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.267="label"*24x53 n="Off Rate: H Gate" Ob=16777215 Og=8421504 Of=-19,0,700,0,0,0,34,"Arial" N.268="const"(1)*58x50 N.269="summingJunction"*65x46 N.270="/"*49x45 N.271="const"(30.001)*23x46 N.272="summingJunction"*37x44 N.273="variable"*67x54 n="beta_H" N.274="const"(10)*39x50 N.275="exp"*54x46 N.276="1/X"*77x47 N.277="display"(1.8830950686725)*69x58 Oe=6 Ox=1 Ov=0 N.278="variable"*67x56 n="RateTempEffect" N.279="*"*91x54 N.280="Compound"*40x21#2,0 n="tau_M" Ms=0,0,0,0,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.281="summingJunction"*80x37 N.282="1/X"*90x38 N.283="variable"*90x33 n="tau_M" N.284="display"(0.12947141605587)*89x31 Oe=6 Ox=1 Ov=0 N.285="meter"(-100,100)*103x35*20x11 n="Tau_M" Tt=1 Tw=0,0,1,"Meter 1" Tc=0,255 N.286="Compound"*36x15#1,1 n="alpha_M" Ms=0,0,0,0,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.287="/"*42x11 N.288="const"(25.001)*9x10 N.289="summingJunction"*23x10 N.290="variable"*42x6 n="alpha_M" N.291="const"(10)*32x15 N.292="exp"*43x17 N.293="/"*56x12 N.294="summingJunction"*50x20 N.295="const"(1)*43x22 N.296="label"*9x6 n="On Rate: M Gate" Ob=16777215 Og=8421504 Of=-19,0,700,0,0,0,34,"Arial" N.297="display"(4.7918168609834)*44x4 Oe=6 Ox=1 Ov=0 N.298="*"*67x6 N.299="variable"*42x8 n="RateTempEffect" N.300="Compound"*36x30#1,1 n="beta_M" Ms=0,0,0,0,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.301="exp"*60x46 N.302="const"(18)*47x49 N.303="variable"*61x53 n="beta_M" N.304="summingJunction"*37x44 N.305="const"(0.001)*24x46 N.306="/"*55x45 N.307="*"*72x46 N.308="const"(4)*68x48 N.309="label"*25x52 n="Off Rate: M Gate" Ob=16777215 Og=8421504 Of=-19,0,700,0,0,0,34,"Arial" N.310="display"(2.9318956808526)*63x57 Oe=6 Ox=1 Ov=0 N.311="variable"*61x55 n="RateTempEffect" N.312="*"*82x53 N.313="variable"*68x49 n="% Inactivation" N.314="variable"*86x19 n="% Activation" N.315="label"*160x35 n="Na Conductance" N.316="*"*178x29 N.317="const"(120)*103x28 N.318="variable"*14x48 n="H_H_V" N.319="variable"*69x46 n="H" N.320="variable"*14x23 n="H_H_V" N.321="variable"*185x30 n="I_Na+" N.322="Compound"*51x78 n="Sodium Current" Ms=2048,0,0,3840,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.323="variable"*5x39 n="V" N.324="Compound"*3x21#0,1 n="Driving_Force_Leak" Ms=2048,0,0,3840,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.325="variable"*93x12 n="G_TempEffect" N.326="*"*104x18 N.327="const"(0.3)*69x20 N.328="Compound"*15x17#0,1 n="G_Leak" Ms=0,0,0,0,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.329="*"*123x29 N.330="integrator"(0,4,0)*30x27 N.331="const"(1)*26x27 N.332="summingJunction"*41x27 N.333="variable"*88x31 n=": Trigger_1" N.334="sign"*55x28 N.335="sign"*56x35 N.336="summingJunction"*41x33#3,1 N.337="const"(1)*25x37 N.338="integrator"(0,5,0)*29x37 N.339="!="*69x30 N.340="not"*78x31 N.341="wirePositioner"*25x32 N.342="label"*6x1 n=" Accommodation " Ob=0 Og=16777215 Of=-24,0,400,0,0,0,18,"Times New Roman" N.343="variable"*133x38 n="Stimulus" N.344="slider"(0.5,50,0)*3x32 N.345="label"*3x30 n="Pulse On At" N.346="label"*5x21 n=" Stimulus Amplitude (uA/cm^2 of Current)" Ob=8454143 Og=255 Of=-16,0,400,0,0,0,18,"Times New Roman" N.347="label"*2x38 n="Pulse Duration" N.348="slider"(0.1,1,0)*7x35 N.349="slider"(0,500,-500)*6x25 N.350="comment"*2x2*99x34 C="Knowledge Objective. The student should recognize that: A nerve's excitability is abolished when the membrane potential is held at a voltage more positive than threshold. Application Objective: The objectives are met when the student can: 1. Explain that the stimulator can only generate passive changes in membrane voltage, that is the membrane is simply acting as a resistor and capacitor. 2. Explain why the potassium current is ~500 mA/cm^2 in the steady state, and increases to~800 mA/cm^2 duirng a maximal depolarization.. 3. Explain why the sodium current changes very little, with even very large stimuli. 4. Compare the relative importance of the increased potassium current versus the absent sodium current in the loss of nerve excitability. " N.351="variable"*63x70 n="Stimulus@359" N.352="Compound"*13x5 n="Objectives" Ms=2048,0,0,3840,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.353="comment"*2x2*98x34 C=" Help Window Blue windows contain additional information and can be opened by double-clicking on them. For instance, double-click (or right click) on the objectives window and you can read this lesson's objectives. To exit, double-click (or right click) somewhere on the yellow background. Sliders can be changed in two ways: Double-click on the clear window to be able to directly enter values. Drag the slider under the clear window to change the value in that clear window. (\"Drag\" means: ) ( 1. Put the pointer on the slider ) ( 2. Hold down the left button on the mouse ) ( 3. Move the mouse to the right or the left. )" N.354="Compound"*10x11 n="Double-Click Here To Get Help" Ms=2048,0,0,3840,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.355="comment"*4x1*96x33 C=" Structure of this Window In this model, additional inward current is passed to bring the membrane potential to -50 mV. Two plots are given on the right of the screen. The top plot shows the membrane potential during the simulation. The bottom plot shows sodium and potassium currents following the stimulus. The wire diagram in the lower left corner implements a stimulator. The slider generates the amplitude of the stimulus, and can be set to much larger values than in other lessons. Blue windows offer additional information. The current window gives the structure of this lesson plan The \"Objectives\" window list the knowledge and application objectives. The \"Help\" window explains how to manipulate the variables in this window. The \"Bibliography\" window lists important citations. The \"Units\" window lists the units of measurement. " N.356="Compound"*8x8 n="Structure of this Window" Ms=2048,0,0,3840,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.357="wirePositioner"*28x49 N.358="not"*80x48 N.359="!="*72x47 N.360="integrator"(0,7,0)*32x55 N.361="const"(1)*27x55 N.362="summingJunction"*44x50#3,1 N.363="sign"*59x52 N.364="sign"*58x45 N.365="variable"*90x48 n=": Trigger_2" N.366="summingJunction"*44x44 N.367="const"(1)*29x44 N.368="integrator"(0,6,0)*33x44 N.369="*"*108x46#3,1 N.370="label"*18x52 n="Pulse Duration" N.371="label"*5x45 n="Pulse On At" N.372="slider"(0,20,0)*3x47 N.373="slider"(-375,50,-500)*89x42 N.374="plot"*248x55*53x14#1,0 pt="Electrical Stimulus" px="Time (sec)" py="uA/cm^2" pax=0 pf=H pf=F pb=10,-200 pbx=6,0 pbY=0,0 pbX=0,0 pc=512 pm=10,0 pb.0=0,-80 pb.1=0,0 pb.2=0,0 pb.3=0,0 N.375="display"(-375)*120x51 Oe=6 Ox=1 Ov=0 N.376="summingJunction"*123x37 N.377="const"(1)*97x50 N.378="wirePositioner"*106x16 N.379="const"(20)*34x52 N.380="variable"*100x49 n="H" N.381="variable"*96x45 n="M_cubed" N.382="plot"*113x44*31x18 px="Time (sec)" pax=0 pf=H pb=0.7,0.02 pbx=3,0 pbY=0,0 pbX=0,0 pc=512 pm=10,0 pb.0=0.7,0.1 pb.1=0.05,0.02 pb.2=0,0 pb.3=0,0 N.383="plot"*108x1*31x18 px="Time (sec)" pax=0 pf=H pb=-100,-200 pbx=3,0 pbY=0,0 pbX=0,0 pc=512 pm=10,0 pb.0=-100,-200 pb.1=0,0 pb.2=0,0 pb.3=0,0 N.384="variable"*93x2 n="I_Na+" N.385="plot"*59x3*31x18 px="Time (sec)" pax=0 pf=H pb=-20,-60 pbx=3,0 pbY=0,0 pbX=0,0 pc=512 pm=10,0 pb.0=-20,-60 pb.1=0,0 pb.2=0,0 pb.3=0,0 N.386="variable"*45x5 n="V" N.387="display"(0.61747312203489)*64x36 Oe=6 Ox=1 Ov=0 N.388="display"(1)*99x278 Oe=6 Ox=1 Ov=0 N.389="variable"*130x30 n="Pulse" N.390="Compound"*7x29#1,0 n="Stimulator" Ms=2048,0,0,3840,0,0 Ml=0 Mr=0 Mh=0 Mp=0 Mw="" N.391="plot"*47x22*57x18#2,0 pt="Membrane Current" px="Time (msec)" pax=0 pf=H pf=F pb=900,-200 pbx=3,0 pbY=0,0 pbX=0,0 pc=512 pm=10,0 pg=3,0pb.0=0,0 pb.1=600,400 pb.2=0,0 pb.3=0,0 N.392="variable"*34x25 n="I_Na+" N.393="variable"*36x34 n="I_K+" G.6=7,31,32,33,34,35,71,72,73,74,75,197,198,199,200,201,202,203, G.8=9,10,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,70,132,133,134,135,136,137,138,139, G.10=11,12, I.13.i1=15.o1 I.14.i1=15.o1 I.15.i1=16.o1 I.15.i2=19.o1 I.15.i3=22.o1 I.15.i4=134.o1 I.16.i1=17.o1 I.18.i1=17.o1 I.19.i1=20.o1 I.21.i1=20.o1 I.22.i1=23.o1 I.24.i1=23.o1 G.28=29,30, I.31.i1=33.o1 I.32.i1=34.o1 I.32.i2=35.o1 G.36=37,38,39,40,41,105,108,109,140,189,190,191,193,194,195,196, I.38.i1=41.o1 I.39.i1=38.o1 I.41.i1=196.o1 I.41.i2=195.o1 G.42=43,44,47,55,56,112,113,141,323,324,328, G.44=45,46, I.47.i1=56.o1 I.49.i1=53.o1 f49.2.i=- I.49.i2=50.o1 I.50.i1=115.o1 I.51.i1=327.o1 I.52.i1=51.o1 I.54.i1=53.o1 I.56.i1=328.o1 I.56.i2=324.o1 G.57=58,59,62,63,64,65,66,67,68,69,142,143,144,145,146,147,148,149,150,151,152,153,154,155, G.59=60,61, I.62.i1=66.o1 I.63.i1=62.o1 I.64.i1=62.o1 I.65.i1=64.o1 I.67.i1=66.o1 I.74.i1=75.o1 I.74.i2=73.o1 I.74.i3=72.o1 I.74.i4=71.o1 I.76.i1=83.o1 I.76.i2=83.o1 I.76.i3=83.o1 I.76.i4=83.o1 I.78.i1=82.o1 f78.2.i=- I.78.i2=79.o1 I.79.i1=83.o1 I.79.i2=194.i2 I.81.i1=80.o1 f81.2.i=- I.81.i2=83.o1 I.82.i1=159.o1 I.82.i2=194.i1 I.83.i1=84.o1 I.84.i1=78.o1 I.85.i1=87.o1 I.86.i1=85.o1 I.87.i1=88.o1 I.88.i1=190.i1 I.88.i2=190.i2 I.90.i1=89.o1 I.90.i2=92.o1 I.91.i1=130.o1 I.91.i2=90.o1 I.92.i1=97.o1 I.94.i1=91.o1 I.95.i1=96.o1 I.95.i2=191.i1 I.97.i1=95.o1 I.97.i2=93.o1 I.99.i1=101.o1 I.99.i2=103.o1 I.101.i1=189.i1 I.101.i2=100.o1 I.102.i1=111.o1 I.104.i1=99.o1 I.107.i1=85.o1 I.108.i1=140.o1 I.109.i1=41.o1 I.111.i1=104.o1 I.111.i2=98.o1 I.113.i1=112.o1 I.114.i1=115.o1 f115.1.i=- I.115.i1=116.o1 I.115.i2=117.o1 f120.1.i=- I.120.i1=119.o1 I.120.i2=118.o1 I.121.i1=120.o1 I.122.i1=123.o1 I.124.i1=123.o1 f124.2.i=- I.124.i2=120.o1 I.126.i1=83.o1 I.127.i1=119.o1 I.128.i1=161.o1 I.129.i1=163.o1 I.130.i1=97.o1 I.130.i2=131.o1 I.133.i1=135.o1 I.134.i1=135.o1 I.136.i1=137.o1 I.136.i2=138.o1 I.136.i3=139.o1 I.140.i1=195.o1 I.141.i1=323.o1 I.143.i1=144.o1 I.144.i1=62.o1 I.144.i2=146.o1 I.147.i1=143.o1 I.148.i1=143.o1 I.149.i1=154.o1 I.150.i1=155.o1 I.151.i1=152.o1 I.153.i1=155.o1 f155.1.i=- I.155.i1=154.o1 f155.2.i=- I.155.i2=151.o1 G.156=2,3, I.157.i1=158.o1 I.159.i1=81.o1 I.161.i1=94.o1 I.161.i2=160.o1 I.163.i1=102.o1 I.163.i2=162.o1 I.164.i1=163.o1 I.165.i1=183.o1 I.169.i1=179.o1 f169.2.i=- I.169.i2=166.o1 I.170.i1=169.o1 I.170.i2=167.o1 G.171=165,166,167,168,169,170,172,173,174,175,176,177,178,179,180,181,182,183,184,185,187,188, I.172.i1=173.o1 I.172.i2=175.o1 I.173.i1=178.o1 f173.2.i=- I.173.i2=176.o1 I.177.i1=182.o1 I.182.i1=174.o1 I.182.i2=172.o1 I.183.i1=168.o1 I.183.i2=170.o1 I.184.i1=182.o1 I.185.i1=183.o1 I.188.i1=187.o1 G.189=77,98,99,100,101,102,103,104,111,129,162,163,164, I.189.o1=164.o1 I.189.o2=163.o1 I.189.i1=105.o1 G.190=85,86,87,88,107, I.190.i1=191.o1 I.190.i2=189.o1 G.191=89,90,91,92,93,94,95,96,97,106,128,130,131,160,161, I.191.o1=161.o1 I.191.i1=105.o1 I.192.i1=195.i1 I.192.i2=110.o1 I.192.i3=186.o1 I.193.i1=194.o1 G.194=76,78,79,80,81,82,83,84,126,159, I.194.o1=76.o1 I.194.i1=191.o1 I.194.i2=189.o2 G.195=110,186,192, I.195.o1=192.o1 I.195.i1=193.o1 G.196=118,119,120,121,122,123,124,125,127, I.196.o1=124.o1 I.202.i1=201.o1 I.202.i3=199.o1 I.202.i4=200.o1 I.203.i1=197.o1 G.204=205,206,207,208,209,210,211,212,213, I.204.o1=207.o1 I.205.i1=212.o1 I.207.i1=208.o1 f207.2.i=- I.207.i2=211.o1 I.209.i1=208.o1 I.210.i1=211.o1 f211.1.i=- I.211.i1=212.o1 I.211.i2=213.o1 G.214=215,216,217,218,219,220,221,222,223,224,225,226,227,387, I.214.o1=216.o1 I.214.o2=227.o1 I.214.i1=286.o1 I.214.i2=300.o1 I.215.i1=218.o1 I.215.i2=218.o1 I.215.i3=218.o1 I.216.i1=215.o1 I.216.i2=217.o1 I.218.i1=226.o1 I.219.i1=224.o1 I.220.i1=225.o1 I.220.i2=214.i1 I.221.i1=222.o1 f221.2.i=- I.221.i2=226.o1 I.223.i1=226.o1 I.223.i2=214.i2 I.224.i1=220.o1 f224.2.i=- I.224.i2=223.o1 I.225.i1=221.o1 I.226.i1=219.o1 I.227.i1=215.o1 G.228=229,230,231,232,233,234,235,236,237,238,239,240,241,388, I.228.o1=241.o1 I.228.o2=235.o1 I.228.i1=253.o1 I.228.i2=266.o1 I.229.i1=233.o1 f229.2.i=- I.229.i2=230.o1 I.230.i1=239.o1 I.230.i2=228.i2 I.232.i1=231.o1 f232.2.i=- I.232.i2=239.o1 I.233.i1=238.o1 I.233.i2=228.i1 I.234.i1=229.o1 I.235.i1=232.o1 I.235.i2=236.o1 I.237.i1=239.o1 I.238.i1=232.o1 I.239.i1=234.o1 I.240.i1=239.o1 I.241.i1=240.o1 I.242.i1=246.o1 I.242.i2=317.o1 I.242.i3=319.o1 I.244.i1=243.o1 I.244.i2=242.o1 I.245.i1=244.o1 I.246.i1=214.o2 G.247=248,249,250,251,252, I.247.i1=253.o1 I.247.i2=266.o1 I.248.i1=250.o1 I.249.i1=250.o1 I.250.i1=251.o1 I.251.i1=247.i1 I.251.i2=247.i2 I.252.i1=248.o1 G.253=254,255,256,257,258,259,260,261,262,263,264,265, I.253.o1=265.o1 I.253.i1=318.o1 I.255.i1=260.o1 I.257.i1=262.o1 I.258.i1=259.o1 I.258.i2=253.i1 I.260.i1=258.o1 I.260.i2=256.o1 I.262.i1=255.o1 I.262.i2=261.o1 I.263.i1=265.o1 I.265.i1=257.o1 I.265.i2=264.o1 G.266=267,268,269,270,271,272,273,274,275,276,277,278,279, I.266.o1=279.o1 I.266.i1=318.o1 I.269.i1=275.o1 I.269.i2=268.o1 I.270.i1=272.o1 I.270.i2=274.o1 I.272.i1=266.i1 I.272.i2=271.o1 I.273.i1=276.o1 I.275.i1=270.o1 I.276.i1=269.o1 I.277.i1=279.o1 I.279.i1=273.o1 I.279.i2=278.o1 G.280=281,282,283,284,285, I.280.i1=286.o1 I.280.i2=300.o1 I.281.i1=280.i1 I.281.i2=280.i2 I.282.i1=281.o1 I.283.i1=282.o1 I.284.i1=283.o1 I.285.i1=283.o1 G.286=287,288,289,290,291,292,293,294,295,296,297,298,299, I.286.o1=298.o1 I.286.i1=320.o1 I.287.i1=289.o1 I.287.i2=291.o1 I.289.i1=288.o1 I.289.i2=286.i1 I.290.i1=293.o1 I.292.i1=287.o1 I.293.i1=287.o1 I.293.i2=294.o1 I.294.i1=292.o1 f294.2.i=- I.294.i2=295.o1 I.297.i1=298.o1 I.298.i1=290.o1 I.298.i2=299.o1 G.300=301,302,303,304,305,306,307,308,309,310,311,312, I.300.o1=312.o1 I.300.i1=320.o1 I.301.i1=306.o1 I.303.i1=307.o1 I.304.i1=300.i1 I.304.i2=305.o1 I.306.i1=304.o1 I.306.i2=302.o1 I.307.i1=301.o1 I.307.i2=308.o1 I.310.i1=312.o1 I.312.i1=303.o1 I.312.i2=311.o1 I.313.i1=228.o2 I.314.i1=214.o1 I.316.i1=204.o1 I.316.i2=245.o1 I.319.i1=228.o1 I.321.i1=316.o1 G.322=204,214,228,245,246,247,253,266,280,286,300,313,314,315,316,317,318,319,320,321,380,381,382,242,243,244,383,384,385,386, G.324=48,49,50,53,54,114,115,116,117, I.324.o1=49.o1 I.326.i1=325.o1 I.326.i2=51.o1 G.328=51,52,325,326,327, I.328.o1=326.o1 I.329.i1=378.o1 I.329.i2=333.o1 I.330.i1=331.o1 I.332.i1=330.o1 f332.2.i=- I.332.i2=341.o1 I.333.i1=340.o1 I.334.i1=332.o1 I.335.i1=336.o1 I.336.i1=341.o1 I.336.i2=348.o1 f336.3.i=- I.336.i3=338.o1 I.338.i1=337.o1 I.339.i1=334.o1 I.339.i2=335.o1 I.340.i1=339.o1 I.341.i1=344.o1 I.343.i1=376.o1 G.352=350,351, G.354=353, G.356=355, I.357.i1=372.o1 I.358.i1=359.o1 I.359.i1=364.o1 I.359.i2=363.o1 I.360.i1=361.o1 I.362.i1=357.o1 I.362.i2=379.o1 f362.3.i=- I.362.i3=360.o1 I.363.i1=362.o1 I.364.i1=366.o1 I.365.i1=358.o1 I.366.i1=368.o1 f366.2.i=- I.366.i2=357.o1 I.368.i1=367.o1 I.369.i1=373.o1 I.369.i2=365.o1 I.369.i3=377.o1 I.375.i1=369.o1 I.376.i1=389.o1 I.376.i2=369.o1 I.378.i1=390.i1 I.382.i1=381.o1 I.382.i2=380.o1 I.383.i1=384.o1 I.385.i1=386.o1 I.387.i1=226.o1 I.389.i1=329.o1 G.390=343,378,329,330,331,332,333,334,335,336,337,338,339,340,341,344,345,347,348,357,358,359,360,361,362,363,364,365,366,367,368,369,370,371,372,373,375,376,377,379,389, I.390.i1=349.o1 I.391.i1=392.o1 I.391.i2=393.o1