localize_currents_M.oc

//------------------------------------------------------------------------
//
//  Procedures to localize mechanisms in dendritic compartments
//
//  Simple version with minimal set of currents:
//	- potassium currents: IKd Traub, IM Zach
//	- INa current: Traub
//	- IKd in dendrites
//
//  Procedures to localize currents as a function of distance
//  (use the path distance function of NEURON)
//
//------------------------------------------------------------------------

strdef sect

soma distance(0,0.5)	// initialize path distances to center of soma

//
//  Procedures to insert mechanisms
//
proc insert_ina() {			// sodium channels
	   insert inaT
	   ena = 50
	   vtraub_inaT = -63			// threshold of -55
	   gnabar_inaT = 3			// zach init segment
	   gnabar_inaT = 20e-4			// zach dendrites & soma
}
proc insert_ikd() {			// delayed-rectifier	
	   insert ikdT
	   ek = -90
	   vtraub_ikdT = -63			// threshold of IKd
	   gkbar_ikdT = 2000e-4			// zach init segment
	   gkbar_ikdT = 200e-4			// zach soma
}
proc insert_im() {			// ca-dependent K+ current
	   insert imZ
	   ek = -90
	   gkbar_imZ = 3e-4			// zach dendrites & soma
}





//
//  Procedure to insert currents in soma, dendrites and axon
//
proc insert_currents() { 

   forsec "dend" {	// dendrites
	insert_ina()		// sodium channels
	insert_im()		// M-channels
	insert_ikd()		// delayed rectifier
   }

   soma {		// soma
	insert_ina()		// sodium channels
	insert_im()		// M-channels
	insert_ikd()		// delayed rectifier
   }

   axon {		// axon
	insert_ina()		// sodium channels
	insert_ikd()		// delayed rectifier
   }
}



//
//  Procedure to set conductances in the soma
//  arguments: 1=gNa, 2=gKd, 3=gM
//
proc set_soma() {

   print " "
   print "Set somatic currents:"
   print " "
   print " Sodium cnannels:  ",$1
   print " IKd channels:     ",$2
   print " IM channels:      ",$3
   print " "

   soma {
	gnabar_inaT = $1	// sodium channels
	gkbar_imZ = $3		// M-channels
	gkbar_ikdT = $2		// delayed rectifier
	if(DEBUG) {
	   sectionname(sect)
	   print "INa, IKd, IM inserted in ",sect
	}
   }
}



//
//  Procedure to set conductances in the axon
//  arguments: 1=gNa, 2=gKd
//
proc set_axon() {

   print " "
   print "Set axonal currents:"
   print " "
   print " Sodium cnannels:  ",$1
   print " IKd channels:     ",$2
   print " "

   axon {
	gnabar_inaT = $1	// sodium channels
	gkbar_ikdT = $2		// delayed rectifier
	if(DEBUG) {
	   sectionname(sect)
	   print "INa, IKd inserted in ",sect
	}
   }
}




//
//  Procedure to set conductances in the dendrites
//  arguments: 1=gNa, 2=gKd, 3=gM
//
proc set_dendrites() {

   print " "
   print "Set dendritic currents:"
   print " "
   print " Sodium cnannels:  ",$1
   print " IKd channels:     ",$2
   print " IM channels:      ",$3
   print " "

   forsec "dend" {
	gnabar_inaT = $1	// sodium channels
	gkbar_imZ = $3		// M-channels
	gkbar_ikdT = $2		// delayed rectifier
	if(DEBUG) {
	   sectionname(sect)
	   print "INa, IKd, IM inserted in ",sect
	}
   }

   forsec "myelin" {
	gnabar_inaT = $1	// sodium channels in myelin are idem dendrites
	if(DEBUG) {
	   sectionname(sect)
	   print "INa inserted in ",sect
	}
   }
}






//
//  Procedure to localize conductances in the dendrites
//  arguments: 1=gNa, 2=gKd, 3=gM, 4=min distance, 5=max distance
//
proc localize_dendrites() {	local i

   print " "
   print "Localize dendritic currents:"
   print " "
   print " Sodium cnannels:  ",$1
   print " IKd channels:     ",$2
   print " IM channels:      ",$3
   print " distance range: ",$4," to ",$5
   print " "

   i=0
   forsec "dend" {
     if( (distance(0.5) >= $4) && (distance(0.5) <= $5) ) {
	gnabar_inaT = $1	// sodium channels
	gkbar_imZ = $3		// M-channels
	gkbar_ikdT = $2		// delayed rectifier
	if(DEBUG) {
	   sectionname(sect)
	   print "INa, IKd, IM inserted in ",sect
	}
     }
     i=i+1
   }
}