Do IFs need a section ?

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AG

Do IFs need a section ?

Post by AG » Tue Oct 25, 2005 4:33 am

Dear All,

I have read the following:

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	: ARTIFICIAL_CELL is a synonym for POINT_PROCESS. However it is also
	: a hint that this model not only has a NET_RECEIVE block and does NOT
	: have a BREAKPOINT but does not have to be associated with a
	: section location or numerical integrator. i.e it does not
	: refer to v or any ions or have a POINTER
But when I try to access to the m value of the IF I obtain:

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oc>objref n1
oc>n1=new IntFire1()
oc>n1.m
nrniv: point process not located in a section near line 5
n1.m
     ^
oc>
I have the same problem when I use NetStim objects to stimulate IF networks. Does the best solution consist in creating a "fake" section and building IF networks into it or did I misunderstood something ?

Thanks for your help !

AG

ted
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Re: Do IFs need a section ?

Post by ted » Tue Oct 25, 2005 10:51 am

Does the best solution consist in creating a "fake" section and building IF networks into it or did I misunderstood something ?
For the present, every artificial cell is a point process and must be "hosted" by a
section, even if that section is a "dummy section" with no significant membrane
properties. This introduces negligible computational overhead.

FYI 1: Launch NEURON's demo program, select the Synchronizing net, and
type psection() at the oc> prompt. You'll see this:

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acell_home_ { nseg=1  L=100  Ra=35.4
        /*location 0 attached to cell 0*/
        /* First segment only */
        insert morphology { diam=500}
        insert capacitance { cm=1}
        insert IntervalFire { tau=10 invl=10}
        insert IntervalFire { tau=10 invl=10.5}
        insert IntervalFire { tau=10 invl=11}
        insert IntervalFire { tau=10 invl=11.5}
        insert IntervalFire { tau=10 invl=12}
        insert IntervalFire { tau=10 invl=12.5}
        insert IntervalFire { tau=10 invl=13}
        insert IntervalFire { tau=10 invl=13.5}
        insert IntervalFire { tau=10 invl=14}
        insert IntervalFire { tau=10 invl=14.5}
}
FYI 2: If you build a network with the NetWork Builder, then export hoc code (click on
its "Hoc code" button) you will find that the first three lines in that file are

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// NetGUI default section. Artificial cells, if any, are located here.
create acell_home_
access acell_home_

AG

Great !

Post by AG » Tue Oct 25, 2005 11:10 am

All is clear now, thank you for your help !

AG.

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