Object Type:    fura2

Description:	Computes fura2 fluorescence in a single difshell.

Author:         E. De Schutter BBF-UIA 1/95

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ELEMENT PARAMETERS

DataStructure:	fura2_type [in src/concen/conc_struct.h]

Size:           104 bytes

Fields:         F340            F340 fluorescence
                F380            F380 fluorescence
                ratio           F340/F380

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SIMULATION PARAMETERS

Function:	FuraRatio [in src/concen/fura2.c]

Classes:        concentration  segment

Actions:        RESET  PROCESS

Messages:       CONCEN  Bfree Bbound vol    (from all fura2 difbuffers)

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Notes:          Computes the fluorescence signal of the fura-2 calcium
                indicator dye by adding together information from a series of
                difbuffers (representing the fura2 in shells).

                In order to use the fura2 object, create difbuffers to model
                the diffusion of the fura-2 dye and Ca buffering for each
                difshell that is associated with a compartment.  The Btot, D,
                kBf, and kBb fields for the difbuffers should be set to values
                that are typical of the ionic environment of the dye.  The
                difbuffers are linked to their difshells with the usual
                messages.

                Then send "CONCEN Bfree Bbound vol" messages to a single fura2
                element from each difbuffer that corresponds to the
                compartment for which you wish to calculate the fura-2
                fluorescence signal.
                
                For a general description of buffered calcium diffusion see:
                De Schutter E., and Smolen P., "Calcium dynamics in large
                neuronal models", in Methods in neuronal modeling: From ions
                to networks (2nd edition), C. Koch and I. Segev editors, pp.
                211-250 (1998).  Details of the GENESIS implementation of the
                fura2 object are given in Sec. 6.6.4.  Also see Blumenfeld et.
                al., Biophys. J. 63: 1146-1164 (1992) for additional
                discussion of fura-2 parameters.

Example:

See also:	difshell, difbuffer
