Object Type:    SynG_object
 
Description:    Implements graded synaptic inhibition in the leech
 
Author:         J. Lu and A. Hill, Calabrese Lab, 3/97
 
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ELEMENT PARAMETERS
 
DataStructure:  SynG_type  [in src/newconn/SynGS_struct.h]
 
Size:           196 bytes
 
Fields:         Ik                 channel current
                Gk                 time varying channel conductance
                Ek                 reversal potential of channel
                A                  shunts effective Ca current
                B                  buffering parameter
                P                  Ca factor governing transmitter release
                C                  limit parameter(limits release to Gbar)
                R                  release = p^3/(p^3+C)
                Gbar               maximal conductance
                A1                 A1 in Ainf=A1+A2/(1+exp(A3+(Vm+A4)))
                A2                 A2
                A3                 A3
                A4                 A4
                A5                 A5 is the time constant
                POWER              POWER

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SIMULATION PARAMETERS
 
Function:       SynG  [in src/newconn/SynG.c]
 
Classes:        device synchannel
 
Actions:        RESTORE2  SAVE2  CHECK  RESET  PROCESS  INIT
 
Messages:       VOLTAGE         presynaptic membrane potential
                CAF             presynaptic fast Ca current, ICaF
                CAS             presynaptic slow Cacurrent, ICaS
                POSTVOLTAGE     postsynaptic membrane potential
 
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Notes:          Simulates graded synaptic transmission designed specifically
                for leech HN cells, based on the synchan object.  Needs
		presynaptic calcium currents (ICaF and ICaS) and presynaptic
		membrane potential as input.  The output is the synaptic
		conductance.  In addition, this object can calculate the
		synpatic current if it is given the postsynaptic membrane
		potential.  This is useful only for the purpose of plotting
		the synaptic current.  The simuation will work without
		calculating synaptic current because the postsynaptic
		compartment calculates the current based on the postsynaptic
		Vm and the synaptic reversal potential.

Example:        See http://calabreselx.biology.emory.edu/software.html.

See also:       synchan, SynE_object, SynS_object
