Modelling reduced excitability in aged CA1 neurons as a Ca-dependent process (Markaki et al. 2005)

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Accession:119266
"We use a multi-compartmental model of a CA1 pyramidal cell to study changes in hippocampal excitability that result from aging-induced alterations in calcium-dependent membrane mechanisms. The model incorporates N- and L-type calcium channels which are respectively coupled to fast and slow afterhyperpolarization potassium channels. Model parameters are calibrated using physiological data. Computer simulations reproduce the decreased excitability of aged CA1 cells, which results from increased internal calcium accumulation, subsequently larger postburst slow afterhyperpolarization, and enhanced spike frequency adaptation. We find that aging-induced alterations in CA1 excitability can be modelled with simple coupling mechanisms that selectively link specific types of calcium channels to specific calcium-dependent potassium channels."
Reference:
1 . Markaki M, Orphanoudakis S, Poirazi P (2005) Modelling reduced excitability in aged CA1 neurons as a calcium-dependent process Neurocomputing 65-66:305-314
Model Information (Click on a link to find other models with that property)
Model Type: Neuron or other electrically excitable cell;
Brain Region(s)/Organism: Hippocampus;
Cell Type(s): Hippocampus CA1 pyramidal GLU cell;
Channel(s): I Na,p; I Na,t; I L high threshold; I N; I A; I K; I M; I K,Ca; I R;
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Activity Patterns; Aging/Alzheimer`s;
Implementer(s):
Search NeuronDB for information about:  Hippocampus CA1 pyramidal GLU cell; I Na,p; I Na,t; I L high threshold; I N; I A; I K; I M; I K,Ca; I R;
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CA1_Aged
template
BasalPath.hoc *
EPSPTuning.hoc *
ExperimentControl.hoc *
ObliquePath.hoc *
RangeRef.hoc *
SynapseBand.hoc *
                            
// This function centralizes parameters so that we won't confuse experimental variable bindings with 
// neurophysiological variable bindings
// written by Terrence Brannon, modified by Yiota Poirazi, July 2001, poirazi@LNC.usc.edu
 

begintemplate ExperimentControl

public morphology_dir, generic_dir, data_dir 
strdef morphology_dir, generic_dir, data_dir

public syscmd
strdef syscmd

public tmp_str, tmp_str2, tmp_str3
strdef tmp_str, tmp_str2, tmp_str3, tmp_str_internal

public defvar, self_define
public add_lib_dir, xopen_geometry_dependent, xopen_generic, xopen_library

public printfile, create_variable

objref this, filep

objref tmpo, tmpo2, tmpo3
public tmpo, tmpo2, tmpo3

objref grapho[20], fileo[20]
public grapho, fileo

proc init () {
  print "object ExperimentControl created.\n"
  sprint(tmp_str,"show_errmess_always(%d)",$1)
  execute1(tmp_str)

  verbose_level=$2

  variable_dump_cleared=0
}


proc clear_variable_dump() {
  sprint(tmp_str, "system(\"rm -rf %s/variable_dump\")", data_dir)
  execute1(tmp_str)
}

proc defvar() {
  if (!variable_dump_cleared) {
    clear_variable_dump()
    variable_dump_cleared=1
  }
    
  sprint(tmp_str,"%s = %s", $s2, $s3)
  execute1(tmp_str)
  dump_variable($s1,$s2,$s3,$s4)
}

proc dump_variable() {

  filep=new File()

  sprint(tmp_str,"%s/variable_dump",data_dir)
  filep.aopen(tmp_str)
  filep.printf("%s\n%s\n%s\n%s\n\n", $s1, $s2, $s3, $s4)
  filep.close()
  
}

proc create_variable() {
  sprint(tmp_str_internal,"%s=%s",$s1,$s2)
  execute1(tmp_str_internal)
}


proc self_define() {
  this = $o1
}

proc xopen_geometry_dependent() {
  sprint(tmp_str,"xopen(\"%s/%s.hoc\")",morphology_dir,$s1)
  execute1(tmp_str)
}

proc xopen_generic() {
  sprint(tmp_str,"xopen(\"%s/%s.hoc\")",generic_dir,$s1)
  execute1(tmp_str)
}

proc xopen_library() {
  sprint(tmp_str, "%s.tmp_str2=lib_dir_%s",this,$s1)
  execute1(tmp_str)
  sprint(tmp_str3,"xopen(\"%s/%s.hoc\")",tmp_str2,$s2)
  print tmp_str3
  execute1(tmp_str3)
}

proc printfile() {
  sprint(tmp_str2, "%s/%s.ps", $s1,$s2)
  tmpo.printfile(tmp_str2)
}

proc add_lib_dir() {
  sprint(tmp_str,"strdef lib_dir_%s",$s1)
  execute1(tmp_str)
  sprint(tmp_str,"lib_dir_%s=\"%s\"",$s1,$s2)
  execute1(tmp_str)
}

endtemplate ExperimentControl



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