Object Type:	vdep_channel

Description:	A Hodgkin-Huxley type voltage-dependent channel, which
		receives activation gate values from other elements.

Author:		M. Wilson, Caltech (2/89)

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ELEMENT PARAMETERS

DataStructure:	vdep_channel_type  [in src/hh/hh_struct.h]

Size:		96 bytes

Fields:		Gk		channel conductance
		Ik		channel current
		Ek		channel reversal potential
		gbar		channel maximum conductance

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SIMULATION PARAMETERS

Function:	VDepChannel  [in src/hh/vchannel.c]

Classes:	segment channel

Actions:	RESET
		PROCESS
		CHECK		[CHECK does nothing]
                SAVE2           invoked with the save command
                RESTORE2        invoked with the restore command

Messages:	VOLTAGE voltage
		MULTGATE gate_state power
		ADDGATE gate_state power 
		GMAX gmax 
		EK Ek

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Notes:	A vdep_channel calculates Gk by multiplying gbar by any number of
	factors of the form (gate_state)^(power).  These are typically
	received with the MULTGATE message from a tabgate element. For
	example, Gk = gbar*h*m^3 could be implemented with:

		addmsg Na_squid/m Na_squid MULTGATE m 3
		addmsg Na_squid/h Na_squid MULTGATE m 1

	Here, m and h are vdep_gate or tabgate elements, and Na_squid is a
	vdep_channel.  Note that the field for the gate variable is called
	'm', regardless of the name of the gate element.

	For most uses, the vdep_channel has been superseded by the
	tabchannel.  It is sometimes used with a table and tabgate element
	to implement conductances which depend on both concentration and
	voltage (e.g. the potassium C-current).

Example:	see Scripts/neurokit/prototypes/traub91chan.g

See also:	hh_channel, tabchannel, tabgate
