classes
active postloc prelist threshold
delay pre preloc valid
postcell precell syn weight
postcelllist precelllist synlist x
SYNTAX
section netcon = new Netcon(&v(x), target, threshold, delay, weight)
netcon = new Netcon(source, target, threshold, delay, weight)
section netcon = new Netcon(&v(x), target)
netcon = new Netcon(source, target)
DESCRIPTION
Network Connection object that defines a synaptic connection between
a source and target. When the source variable passes threshold in the
positive direction at time t-delay, the target will receive an event
at time t along with weight information. There is no limit on delay
except that it be >= 0 and there is no limit on the number of events
pending delivery.
If the optional threshold, delay, and weight arguments are not
specified, their default values are 10, 1, and 0 respectively. In
any case, their values can be specified after the netcon has been
constucted, see threshold weight and delay .
The target must be a PointProcess that defines a NET_RECEIVE procedure.
The number of NET_RECEIVE procedure arguments define a weight vector
whose elements can be accessed with through the NetCon.weight ( weight )variable
but the weight argument in the above constructors specify the value of
the first argument, with the normal interpretation of weight or maximum
conductance. On initialization, all weight elements with index > 0 are
set to 0.
The source is normally a reference to a membrane potential which is
watched during simulation for passage past threshold. The
currently accessed section is required by the local variable
time step method in order to determine the source "cell".
Any range variable may be a source variable but I suspect that membrane
potential is the only practical one. The source may also
be a PointProcess which contains a "x" variable which is watched for
threshold crossing.
A source used by multiple NetCon instances is shared by those instances
to allow faster threshold detection (ie on a per source basis instead
of a per NetCon basis) Therefore, there is really only one threshold
for all NetCon objects that share a source. However, delay and weight
are distinct for each NetCon object.
From a NetCon instance, various lists of NetCon's can be created
with the same target, precell, or postcell. See netconlist
for creation of NetCon lists from a target, precell, or postcell
pattern or object.
BUGS
NetCon can currently only be used if a CVode object exists.
NetCon
SYNTAX
boolean = netcon.valid()
DESCRIPTION
Returns 0 if the source or target have been freed. If the NetCon object
is used when it is not valid a runtime error message will be printed on
the console terminal.
NetCon
SYNTAX
boolean = netcon.active(boolean)
boolean = netcon.active()
DESCRIPTION
Turns the synapse on or off in the sense that when off, no events
are delivered using this NetCon instance. Returns the previous
state (or current state if no argument).
NetCon
SYNTAX
target_object = netcon.syn()
DESCRIPTION
Returns a reference to the synaptic target PointProcess.
NetCon
SYNTAX
source_object = netcon.pre()
DESCRIPTION
Returns a reference to the source PointProcess. If the source is a membrane
potential then the return value is NULLobject
NetCon
SYNTAX
{x = netcon.preloc() ... pop_section()}
DESCRIPTION
The source section is pushed onto the section stack so that it is
the currently accessed section. Pop_section must be called after you are
finished with the section.
BUGS
The return value of x is .5 if the source was a membrane potential and
therefore does not necessarily correspond to the actual x value location.
If the source was an object, the section is not pushed and the return
value is -1.
NetCon
SYNTAX
{x = netcon.postloc() ... pop_section()}
DESCRIPTION
The section of the target point process is pushed onto the section stack
so that it is the currently accessed section. Pop_section must be called
after you are finished with the section. The x return value is the
relative location of the point process in that section.
NetCon
SYNTAX
cellobj = netcon.precell()
DESCRIPTION
If the source is a membrane potential and the section was declared in
an object (defined in a cell template), a reference to the presynaptic cell
(object) is returned.
NetCon
SYNTAX
cellobj = netcon.postcell()
DESCRIPTION
If the synaptic point process is located in a section which was declared in
an object (defined in a cell template), a reference to the postsynaptic cell
(object) is returned.
NetCon
SYNTAX
List = netcon.prelist()
List = netcon.prelist(List)
DESCRIPTION
List of all the NetCon objects with source the same as netcon.
With no argument, a new List is created.
If the List arg is present, the objects are appended.
NetCon
SYNTAX
List = netcon.synlist()
List = netcon.synlist(List)
DESCRIPTION
List of all the NetCon objects with target the same as netcon.
With no argument, a new List is created.
If the List arg is present, the objects are appended.
SEE ALSO
netconlist
NetCon
SYNTAX
List = netcon.postcelllist()
List = netcon.postcelllist(List)
DESCRIPTION
List of all the NetCon objects with postsynaptic cell object the same as netcon.
With no argument, a new List is created.
If the List arg is present, the objects are appended.
SEE ALSO
netconlist
NetCon
SYNTAX
List = netcon.precelllist()
List = netcon.precelllist(List)
DESCRIPTION
List of all the NetCon objects with presynaptic cell object the same as netcon.
With no argument, a new List is created.
If the List arg is present, the objects are appended.
SEE ALSO
netconlist
NetCon
SYNTAX
del = netcon.delay
netcon.delay = del
DESCRIPTION
Time (ms) between source crossing threshold and delivery of event
to target. Any number of threshold events may occur before delivery of
previous events. delay may be any value >= 0.
NetCon
SYNTAX
w = netcon.weight
netcon.weight = w
x = netcon.weight[i]
netcon.weight[i] = x
DESCRIPTION
Weight variable which is delivered to the target point processes
NET_RECEIVE procedure. The number of arguments in the model descriptions
NET_RECEIVE procedure determines the size of the weight vector.
Generally the 0th element (no index required) refers to synaptic weight
and remaining elements are used as storage by a synaptic model for purposes
of distinguishing NetCon streams of events.
NetCon
SYNTAX
th = netcon.threshold
netcon.threshold = th
DESCRIPTION
Source threshold. Note that many NetCon objects may share the same
source.
NetCon
SYNTAX
x = netcon.x
netcon.x = x
DESCRIPTION
Value of the source variable which is watched for threshold crossing.
If the source is a membrane potential then netcon.x is a reference to
that potential. If the source is an object, then netcon.x is a reference
to the objects field called "x", ie source.x .
neuron/neuron/classes/netcon.hel : Feb 2 08:47