## Multiple Gap Junctions on a Single Neuron

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### Multiple Gap Junctions on a Single Neuron

Hello,

I am trying to connect a Neuron with 2 other neurons by gap junctions using the pointer method but my code doesn't seem to work. Is it possible to have more than 1 Gap Junction on a single neuron? If yes, is there anything in particular regarding distance between the 2 Gap Junctions etc that I need to keep in mind?
Code: Select all
`       func lambda(){local i   if(numarg()==0){      print "Calculate decay length(um) with"      print "  Ra(ohm-cm), Rm(ohm-cm^2), diameter(um)"      return 0   }   i=50*sqrt(\$2*\$3/\$1)   return i}//-------------------------------------------------------------------------------// Build up a model with three neurons which own Na and K channels acting as // Hodgkin-Huxley modelcreate neuron[6]// create standard hh neuronsproc NeuronGeometry(){ local i,dlamda,n   if(numarg()!=2){      print "Create neurons with cell length(um),cell diameter(um)"      return   }   // create standard hh neurons   for(i=0; i<6; i+=1){      access neuron[i]      cm = 1      Ra = 35.4         L = \$1      diam = \$2      insert hh         ena       = 50      ek        = -77      gnabar_hh    = 0.12      gkbar_hh    = 0.036      gl_hh       = 0.0003      el_hh        = -54.3      dlamda = lambda(Ra,1.0/gl_hh,diam)/50            n= L/dlamda         n = int(n/2)*2+1      nseg=n   }}NeuronGeometry(5000,25)//-------------------------------------------------------------------------------//construct gap junctions between each neuron pair for 1st oscillatorobjref gpre[7],gpost[7]for(i=0;i<3;i+=1){   neuron[i]    gpre[i]  = new Gap(0.999)   neuron[(i+1)%3]    gpost[i] = new Gap(0.001)   setpointer  gpre[i].vnb,  neuron[(i+1)%3].v(0.001)   setpointer  gpost[i].vnb, neuron[i].v(0.999)}//adjust gap junction conductanceproc gap_r(){local i   if(numarg()!=3){      print "provide gap_n0-n1 , gap_n1-n2, and gap_n2-n0 value(MOhm)"      return   }   for(i=1;i<=3;i+=1){      gpre[i-1].r = \$i      gpost[i-1].r= \$i   }}   gap_r(0.9524,0.9524,0.9524)         //construct gap junctions between each neuron pair for 1st oscillator over// create two stimuli objects(for first oscillator, neuron 0, 1 and 2) access neuron[0]objref st[2]for(i=0;i<2;i+=1){   st[i]      = new IClamp(0.01)     st[i].del   = 0.5     st[i].dur    = 0.05   }proc SetST(){   if(numarg()==0){      print "Set stimulator with interval(ms),st[0] amp,st[1]amp"      return   }   st[1].del = 0.5 + \$1   st[0].amp=\$2   st[1].amp=\$3}SetST(2,295.5,300)//construct gap junctions between each neuron pair for 2nd oscillator   neuron[3]   gpre[3]  = new Gap(0.999)   neuron[4]   gpost[3] = new Gap(0.001)   setpointer  gpre[3].vnb,  neuron[4].v(0.001)   setpointer  gpost[3].vnb, neuron[3].v(0.999)   neuron[4]   gpre[4]  = new Gap(0.999)   neuron[5]   gpost[4] = new Gap(0.001)   setpointer  gpre[4].vnb,  neuron[5].v(0.001)   setpointer  gpost[4].vnb, neuron[4].v(0.999)   neuron[5]   gpre[5]  = new Gap(0.999)   neuron[3]   gpost[5] = new Gap(0.001)   setpointer  gpre[5].vnb,  neuron[3].v(0.001)   setpointer  gpost[5].vnb, neuron[5].v(0.999)//adjust gap junction conductanceproc gap_r2(){local i   if(numarg()!=3){      print "provide gap_n6-n4 , gap_n4-n5, and gap_n5-n6 value(MOhm)"      return   }         gpre[3].r = \$1      gpost[3].r= \$1      gpre[4].r = \$2      gpost[4].r= \$2      gpre[5].r = \$3      gpost[5].r= \$3      }     gap_r2(0.9524,0.9524,0.9524)       // gap_r2(.1,.1,.1)       //gap_r(.98,.98,.98)//construct gap junctions between each neuron pair for 2nd oscillator over// create two stimuli objects(for second oscillator, neuron 3, 4 and 5)access neuron[3]objref st2[2]for(i=0;i<2;i+=1){   st2[i]      = new IClamp(0.01)   st2[i].del   = .5   st2[i].dur    = 0.05   }proc SetST2(){   if(numarg()==0){      print "Set stimulator with interval(ms),st[0] amp,st[1]amp"      return   }   st2[1].del = .5 + \$1   st2[0].amp=\$2   st2[1].amp=\$3}SetST2(2,295.5,300)//Connecting neurons 2 and 3 with gap junction..      neuron[2] gpre[6]  = new Gap(0.980)      neuron[3] gpost[6] = new Gap(0.010)      setpointer gpre[6].vnb, neuron[3].v(0.010)      setpointer gpost[6].vnb,neuron[2].v(0.980)      gpre[6].r=.98gpost[6].r=.98dt=0.001Dt=0.01vinit = -65celsius = 25`

In my code, there are 2 Neurons that need to have more than one gap junctions Neurons 2 and 3

Regards,
Priti
Priti Gupta

Posts: 5
Joined: Mon Jul 02, 2012 5:15 am

### Re: Multiple Gap Junctions on a Single Neuron

Priti Gupta wrote:my code doesn't seem to work.
How do you know? If an error message is generated, what is the error message?
Is it possible to have more than 1 Gap Junction on a single neuron? If yes, is there anything in particular regarding distance between the 2 Gap Junctions etc that I need to keep in mind?
Yes. No.
ted