Kinetic block error message

[Annik]

In writing a mod file for extracellular chloride management, I get an error message that a) I don't understand the cause of and b) I'm not sure how to fix. I have:

Code: Select all

PARAMETER {
	clbath  = 140	(mM)		:Resting clo concentration	
	fhspace	= 350	(angstrom)
	txfer	= 5	(ms)		:Time constant of Clo 
	DFree 	= 2.03	(um2/ms)
	diam		(um)
}

ASSIGNED {
	icl 	(mA/cm2)	
}

STATE {
	clo	(mM)	
}

INITIAL {
	clo = clbath
		
} 

BREAKPOINT {
	SOLVE state METHOD euler	
}

KINETIC state {
		COMPARTMENT (1e-4)*diam*PI*fhspace {clo}
		LONGITUDINAL_DIFFUSION (1e-4)*DFree*diam*PI*fhspace {clo}
		~clo << (1e8)*(-icl*PI)/(fhspace*FARADAY)+((clbath - clo)/txfer)

But I get the following error message:

syntax error:
Illegal statement:
Illegal block at line 59 in file ./extracl.mod
~clo << (1e8)*(-icl*PI)/(fhspace*FARADAY)+((clbath - clo)/txfer)
___________^

What is the correct syntax here?

[ted]

As soon as possible, please read
Integration methods for SOLVE statements
in the Forum's "Hot tips" area. If that doesn't take care of the problem, let me know.

You will find many other useful bits about NMODL in chapter 9 of The NEURON Book,
or the predecessor of that chapter
Hines, M.L. and Carnevale, N.T.
Expanding NEURON's repertoire of mechanisms with NMODL.
Neural Computation 12:995-1007, 2000
which is available from a link at http://www.neuron.yale.edu/neuron/nrnpubs

[Annik]

Using cnexp, derivimplicit and sparse all gave the same error message. I have read through most of Chapter 9 and some of the programmer's reference, but a lot of the instructions about syntactic rules seem to be given with specific examples, and I have not yet seen an example that explains why this syntax error might come up.

[ted]

OK, I'll have to reproduce the problem myself. Zip up the mod file and enough hoc code to reproduce the error message and email it to me
ted dot carnevale at yale dot edu
and I'll let you know what I find out. No .o, .c, or .dll files, please--just hoc, mod, and whatever ses files might be involved.

--Ted