You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
131 lines
3.2 KiB
131 lines
3.2 KiB
TITLE Model of glycine receptors |
|
|
|
COMMENT |
|
----------------------------------------------------------------------------- |
|
|
|
Kinetic model of glycine receptors |
|
=============================== |
|
|
|
6-state gating model with |
|
2 open states provide dual exponential response. |
|
|
|
O1 |
|
| |
|
C0 -- C1 -- C2 -- O2 |
|
| |
|
D1 |
|
|
|
----------------------------------------------------------------------------- |
|
|
|
This mod file does not include mechanisms for the release and time course |
|
of transmitter; it is to be used in conjunction with a sepearate mechanism |
|
to describe the release of transmitter and that provides the concentration |
|
of transmitter in the synaptic cleft (to be connected to pointer C here). |
|
|
|
Default parameters are set for a miniature EPSC. |
|
|
|
|
|
----------------------------------------------------------------------------- |
|
|
|
Paul B. Manis, Ph.D. 28 Dec 2009 |
|
|
|
----------------------------------------------------------------------------- |
|
ENDCOMMENT |
|
|
|
INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)} |
|
|
|
NEURON { |
|
POINT_PROCESS Gly6S |
|
POINTER XMTR |
|
RANGE C0, C1, C2, D1, O1, O2, Open |
|
RANGE Erev |
|
RANGE Rb, Ru1, Ru2, Rd, Rr, Ro1, Rc1, Ro2, Rc2 |
|
RANGE g, rb, gmax |
|
RANGE CellType : 0 is bushy, 1 is stellate |
|
NONSPECIFIC_CURRENT i |
|
} |
|
|
|
UNITS { |
|
(nA) = (nanoamp) |
|
(mV) = (millivolt) |
|
(pS) = (picosiemens) |
|
(umho) = (micromho) |
|
(mM) = (milli/liter) |
|
(uM) = (micro/liter) |
|
} |
|
|
|
PARAMETER { |
|
|
|
Erev = -70 (mV) : reversal potential |
|
gmax = 500 (pS) : maximal conductance |
|
CellType = 0 (1) : Cell type definition. |
|
: Rates |
|
: Bushy cell IPSCs: (rates can be changed externally) |
|
: Set per Fits 8 March 2010 (see Synapses.py as well) |
|
Rd = 1.177999 (/ms) : desensitization |
|
Rr = 0.000005 (/ms) : resensitization |
|
Rb = 0.009403 (/mM /ms): binding |
|
: diffusion limited |
|
Ru2 = 0.000086 (/ms) : unbinding (2nd site) |
|
Ro1 = 0.187858 (/ms) : opening (fast) |
|
Ro2 = 1.064426 (/ms) : opening (slow) |
|
Ru1 = 0.028696 (/ms) : unbinding (1st site) |
|
Rc1 = 0.103625 (/ms) : closing |
|
Rc2 = 1.730578 (/ms) : closing |
|
|
|
} |
|
|
|
ASSIGNED { |
|
v (mV) : postsynaptic voltage |
|
i (nA) : current = g*(v - Erev) |
|
g (pS) : conductance |
|
XMTR (mM) : pointer to glutamate concentration |
|
rbind (/ms) : binding |
|
Open (1) |
|
} |
|
|
|
STATE { |
|
: Channel states (all fractions) |
|
C0 : unbound |
|
C1 : single gly bound |
|
C2 : double gly bound |
|
D1 : double gly bound, desensitized |
|
O1 : double gly bound, open state 1 |
|
O2 : double gly bound, open state 2 |
|
} |
|
|
|
INITIAL { |
|
|
|
XMTR = 0 |
|
C0 = 1 |
|
C1 = 0 |
|
C2 = 0 |
|
D1 = 0 |
|
O1 = 0 |
|
O2 = 0 |
|
} |
|
|
|
BREAKPOINT { |
|
SOLVE kstates METHOD sparse |
|
:VERBATIM |
|
: if (XMTR > 0.1) { |
|
: fprintf(stderr, "t = %f XMTR = %f\n", t, XMTR); |
|
: } |
|
: ENDVERBATIM |
|
Open = (O1 + O2) |
|
g = gmax * Open |
|
i = (1e-6)*g*(v-Erev) |
|
} |
|
|
|
|
|
KINETIC kstates { |
|
|
|
rbind = Rb * (1e3) * XMTR |
|
|
|
~ C0 <-> C1 (rbind,Ru1) |
|
~ C1 <-> C2 (rbind*2.0,Ru2) |
|
~ C2 <-> O1 (Ro1,Rc1) |
|
~ C2 <-> D1 (Rd,Rr) |
|
~ C2 <-> O2 (Ro2,Rc2) |
|
CONSERVE C0+C1+C2+D1+O1+O2 = 1 |
|
}
|
|
|