CA1 pyramidal neuron: synaptic plasticity during theta cycles (Saudargiene et al. 2015)

 Download zip file   Auto-launch 
Help downloading and running models
Accession:157157
This NEURON code implements a microcircuit of CA1 pyramidal neuron and consists of a detailed model of CA1 pyramidal cell and four types of inhibitory interneurons (basket, bistratified, axoaxonic and oriens lacunosum-moleculare cells). Synaptic plasticity during theta cycles at a synapse in a single spine on the stratum radiatum dendrite of the CA1 pyramidal cell is modeled using a phenomenological model of synaptic plasticity (Graupner and Brunel, PNAS 109(20):3991-3996, 2012). The code is adapted from the Poirazi CA1 pyramidal cell (ModelDB accession number 20212) and the Cutsuridis microcircuit model (ModelDB accession number 123815)
Reference:
1 . Saudargiene A, Cobb S, Graham BP (2015) A computational study on plasticity during theta cycles at Schaffer collateral synapses on CA1 pyramidal cells in the hippocampus. Hippocampus 25:208-18 [PubMed]
Model Information (Click on a link to find other models with that property)
Model Type: Synapse; Dendrite;
Brain Region(s)/Organism:
Cell Type(s): Hippocampus CA1 pyramidal cell; Hippocampus CA1 basket cell; Hippocampus CA1 bistratified cell; Hippocampus CA1 axo-axonic cell;
Channel(s):
Gap Junctions:
Receptor(s):
Gene(s):
Transmitter(s):
Simulation Environment: NEURON;
Model Concept(s): Long-term Synaptic Plasticity; STDP;
Implementer(s): Saudargiene, Ausra [ausra.saudargiene at gmail.com];
Search NeuronDB for information about:  Hippocampus CA1 pyramidal cell;
/
SaudargieneEtAl2015
readme.html
ANsyn.mod *
bgka.mod *
bistableGB_DOWNUP.mod
burststim2.mod *
cad.mod
cadiffus.mod *
cagk.mod *
cal.mod *
calH.mod *
car.mod *
cat.mod *
ccanl.mod *
d3.mod *
gabaa.mod *
gabab.mod *
glutamate.mod *
gskch.mod *
h.mod
hha_old.mod *
hha2.mod *
hNa.mod *
IA.mod
ichan2.mod
Ih.mod *
kadbru.mod
kadist.mod *
kapbru.mod
kaprox.mod *
Kaxon.mod *
kca.mod *
Kdend.mod *
km.mod *
Ksoma.mod *
LcaMig.mod *
my_exp2syn.mod *
Naaxon.mod *
Nadend.mod *
nap.mod
Nasoma.mod *
nca.mod *
nmda.mod *
nmdaca.mod *
regn_stim.mod *
somacar.mod *
STDPE2Syn.mod *
apical-non-trunk-list.hoc
apical-tip-list.hoc
apical-tip-list-addendum.hoc
apical-trunk-list.hoc
axoaxonic_cell17S.hoc
axon-sec-list.hoc
BasalPath.hoc
basal-paths.hoc
basal-tree-list.hoc
basket_cell17S.hoc
bistratified_cell13S.hoc
burst_cell.hoc
current-balance.hoc *
main.hoc
map-segments-to-3d.hoc *
mod_func.c
mosinit.hoc
ObliquePath.hoc *
oblique-paths.hoc
olm_cell2.hoc
pattsN100S20P5_single.dat
PC.ses
peri-trunk-list.hoc
pyramidalNeuron.hoc
randomLocation.hoc
ranstream.hoc
screenshot.png
soma-list.hoc
stim_cell.hoc *
vector-distance.hoc
                            
COMMENT
-----------------------------------------------------------------------------
Simple synaptic mechanism derived for first order kinetics of
binding of transmitter to postsynaptic receptors.

A. Destexhe & Z. Mainen, The Salk Institute, March 12, 1993.
-----------------------------------------------------------------------------

During the arrival of the presynaptic spike (detected by threshold 
crossing), it is assumed that there is a brief pulse (duration=Cdur)
of neurotransmitter C in the synaptic cleft (the maximal concentration
of C is Cmax).  Then, C is assumed to bind to a receptor Rc according 
to the following first-order kinetic scheme:

Rc + C ---(Alpha)--> Ro							(1)
       <--(Beta)--- 

where Rc and Ro are respectively the closed and open form of the 
postsynaptic receptor, Alpha and Beta are the forward and backward
rate constants.  If R represents the fraction of open gates Ro, 
then one can write the following kinetic equation:

dR/dt = Alpha * C * (1-R) - Beta * R					(2)

and the postsynaptic current is given by:

Isyn = gmax * R * (V-Erev)						(3)

where V is the postsynaptic potential, gmax is the maximal conductance 
of the synapse and Erev is the reversal potential.

If C is assumed to occur as a pulse in the synaptic cleft, such as

C     _____ . . . . . . Cmax
      |   |
 _____|   |______ . . . 0 
     t0   t1

then one can solve the kinetic equation exactly, instead of solving
one differential equation for the state variable and for each synapse, 
which would be greatly time consuming...  

Equation (2) can be solved as follows:

1. during the pulse (from t=t0 to t=t1), C = Cmax, which gives:

   R(t-t0) = Rinf + [ R(t0) - Rinf ] * exp (- (t-t0) / Rtau )		(4)

where 
   Rinf = Alpha * Cmax / (Alpha * Cmax + Beta) 
and
   Rtau = 1 / (Alpha * Cmax + Beta)

2. after the pulse (t>t1), C = 0, and one can write:

   R(t-t1) = R(t1) * exp (- Beta * (t-t1) )				(5)

There is a pointer called "pre" which must be set to the variable which
is supposed to trigger synaptic release.  This variable is usually the
presynaptic voltage but it can be the presynaptic calcium concentration, 
or other.  Prethresh is the value of the threshold at which the release is
initiated.

Once pre has crossed the threshold value given by Prethresh, a pulse
of C is generated for a duration of Cdur, and the synaptic conductances
are calculated accordingly to eqs (4-5).  Another event is not allowed to
occur for Deadtime milliseconds following after pre rises above threshold.

The user specifies the presynaptic location in hoc via the statement
	connect pre_GLU[i] , v.section(x)

where x is the arc length (0 - 1) along the presynaptic section (the currently
specified section), and i is the synapse number (Which is located at the
postsynaptic location in the usual way via
	postsynaptic_section {loc_GLU(i, x)}
Notice that loc_GLU() must be executed first since that function also
allocates space for the synapse.
-----------------------------------------------------------------------------
  GLUTAMATE SYNAPSE (AMPA-Kainate receptors)

  Parameters estimated from whole cell recordings of synaptic currents on
  Cochlear neurons (Raman & Trussel, Neuron 9: 173-186, 1992) as well as
  from sharp electrode EPSPs recordings in thalamocortical neurons (LGN)
  (Crunelli et al. J. Physiol. 384: 603, 1987).

-----------------------------------------------------------------------------
ENDCOMMENT



INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)}

NEURON {
	POINT_PROCESS GLU
	POINTER pre
	RANGE C, R, R0, R1, g, gmax, lastrelease
	NONSPECIFIC_CURRENT i
	GLOBAL Cmax, Cdur, Alpha, Beta, Erev, Prethresh, Deadtime, Rinf, Rtau
}
UNITS {
	(nA) = (nanoamp)
	(mV) = (millivolt)
	(umho) = (micromho)
	(mM) = (milli/liter)
}

PARAMETER {
	Cmax	= 1	(mM)		: max transmitter concentration
	Cdur	= 1.1	(ms)		: transmitter duration (rising phase)
	Alpha	= 10	(/ms mM)	: forward (binding) rate
	Beta	= 0.5	(/ms)		: backward (unbinding) rate
	Erev	= 0	(mV)		: reversal potential
	Prethresh = 0 			: voltage level nec for release
	Deadtime = 0	(ms)		: mimimum time between release events
	gmax		(umho)		: maximum conductance
}


ASSIGNED {
	v		(mV)		: postsynaptic voltage
	i 		(nA)		: current = g*(v - Erev)
	g 		(umho)		: conductance
	C		(mM)		: transmitter concentration
	R				: fraction of open channels
	R0				: open channels at start of release
	R1				: open channels at end of release
	Rinf				: steady state channels open
	Rtau		(ms)		: time constant of channel binding
	pre 				: pointer to presynaptic variable
	lastrelease	(ms)		: time of last spike
}

INITIAL {
	R = 0
	C = 0
	Rinf = Cmax*Alpha / (Cmax*Alpha + Beta)
	Rtau = 1 / ((Alpha * Cmax) + Beta)
	lastrelease = -9e9
}

BREAKPOINT {
	SOLVE release
	g = gmax * R
	i = g*(v - Erev)
}

PROCEDURE release() { LOCAL q
	:will crash if user hasnt set pre with the connect statement 

	q = ((t - lastrelease) - Cdur)		: time since last release ended

						: ready for another release?
	if (q > Deadtime) {
		if (pre > Prethresh) {		: spike occured?
			C = Cmax			: start new release
			R0 = R
			lastrelease = t
		}
						
	} else if (q < 0) {			: still releasing?
	
		: do nothing
	
	} else if (C == Cmax) {			: in dead time after release
		R1 = R
		C = 0.
	}

	if (C > 0) {				: transmitter being released?
		    R = Rinf + (R0 - Rinf) * exptable (- (t - lastrelease) / Rtau)

:
: This synapse produces a negative R when it is first hit with
: neurotransmitter.
:
:		if (R < 0) {
:			printf("\t**negative R: %e\n", R)
:			}
:
	} else {				: no release occuring

  	   R = R1 * exptable (- Beta * (t - (lastrelease + Cdur)))
	}

:	printf ("----------------------------------------\n")
:	printf ("q: %f Deadtime: %f pre: %f\n", q, Deadtime, pre )
:	printf ("C: %f R: %.12f t: %f lastrelease: %f\n", C, R, t, lastrelease)

	VERBATIM
	return 0;
	ENDVERBATIM
}

FUNCTION exptable(x) { 
	TABLE  FROM -10 TO 10 WITH 2000

	if ((x > -10) && (x < 10)) {

		exptable = exp(x)
	} else {
		exptable = 0.
	}
}

Loading data, please wait...