# 8.4 Modeling cell assemblies  (Page 7/9)

 Page 7 / 9

## Network size and patterns

In the simulations there will be 50 E-cells and 50 I-cells. The Network will be "trained" to encode assemblies by running the weight producing algorithm on a set of patterns, each which represents a cell assembly (remember weights are only produced between the E-cells initially). There will be 8 patterns that contain 8 E-Cells in each. Each "event" or pattern will carry equal significance when the weighting algorithm runs. To help visualize the patterns look at the diagram below.

## Parameters for cells

Below are tables with parameter that are given exactly from A Lansner and E Fransen.

 Parameter E-Cell I-Cell ${V}_{leak}$ (mV) -50 -70 ${G}_{core}$ 0.04 0.0638 ${G}_{m}$ Soma $\left(\mu S\right)$ 0.0032 0.0016 ${C}_{m}$ Soma $\left(nF\right)$ 0.032 0.016 ${G}_{m}$ $\left(\mu S\right)$ Dentrites 0.0096 0.0096 ${C}_{m}$ Dentrites $\left(nF\right)$ 0.288 0.288 ${V}_{Na}$ 40 50 ${G}_{Na}$ $\left(\mu S\right)$ 1.0 1.0 ${V}_{K}$ -70 -90 ${G}_{K}$ $\left(\mu S\right)$ 0.5 1.0 ${V}_{Ca}$ 150 150 ${G}_{Ca}$ $\left(\mu S\right)$ 0 0 ${G}_{K\left(Ca\right)}$ $\left(\mu S\right)$ 0.0017 0.01 ${\rho }_{AP}$ (mV ${}^{-1}$ ms ${}^{-1}$ ) 4 0.013 ${\delta }_{AP}$ ms ${}^{-1}$ .075 .02
 m h n q p A (mV ${}^{-1}$ ms ${}^{-1}$ ) 0.2 0.08 0.02 0.08 0.7 (ms ${}^{-1}$ ) $\alpha$ B (mV) -40 -40 -15 -25 C (mV) 1 1 0.8 1 17 A (mV ${}^{-1}$ ms ${}^{-1}$ ) 0.06 0.4 0.04 0.005 0.1 (ms ${}^{-1}$ ) $\beta$ B (mV) -49 -36 -40 -20 C (mV) 20 2 0.4 20 17
 m h n q A (mV ${}^{-1}$ ms ${}^{-1}$ ) 0.2 0.08 0.02 0.08 $\alpha$ B (mV) -30 -30 -21 -15 C (mV) 1 0.2 0.2 1 A (mV ${}^{-1}$ ms ${}^{-1}$ ) 0.06 0.4 0.02 0.005 $\beta$ B (mV) -38 -26 -18 -10 C (mV) 20 0.2 0.2 20
 ${V}_{syn}$ Excitatory 0 $mV$ ${V}_{syn}$ Inhibitory -85 $mV$ $s$ variable ${G}_{syn}$ E to E (AMPA) ${w}_{ij}$ x ${w}_{E2E}$ ${G}_{syn}$ E to I (AMPA) ${w}_{ij}$ x ${w}_{E2I}$ ${G}_{syn}$ I to E ${g}_{I2E}$ ${G}_{NMDA}$ E to E ${G}_{syn}$ x ${w}_{NMDA}scalar$ ${\rho }_{NMDA}$ E to E ${G}_{syn}$ x ${\rho }_{NMDA}scalar$ ${\delta }_{NMDA}$ $m{s}^{-1}$ .02

## Remaining parameters

There are a few parameters that remain to be given values. A Lanser and Fransen do not give exact values for these unknown parameters, but instead a desired range for EPSP's (Excitatory Post Synaptic Potentials) that the parameters help determine. By experimenting with a single neuron we can find the ideal range for these unknown parameters. Hence, we can then scale the resulting Weights from the algorithm so they are mapped to the ideal range. We need an overall weighting scale constant for connections from E to E cells (AMPA), ${w}_{E2E}$ . A weighting scale constant for E to I cells, ${w}_{E2I}$ Also, a scale general conductance constant for all I to E connections, ${g}_{I2E}$ . The NMDA connections will be proportional to the AMPA weight but scaled by a constant ${w}_{NMDA}scalar$ . The influx parameter ${\rho }_{NMDA}$ for the $\left[C{a}_{NMDA}\right]$ pool is also proportional to the AMPA weight. Lastly, the binary variable $s$ needs to be given a time duration to stay active for. This time duration may be chosen different for each type of connection class as well (meaning E to E, E to I, and I to E).

Most of these unfixed variables relate to the strength of connections between cells and the EPSPs or IPSPs they create. The reason they won't be fixed for all different size simulations is that the values should vary according to size of the networks and assemblies. For instance, if we model on large networks that have large assemblies we would desire that a cell would require synaptic input from more cells in order to fire, than when the network is small. By picking these numbers accordingly we will be able to roughly determine how many cells of an assembly need to be firing in order to fully activate the assembly.

Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
what does nano mean?
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Got questions? Join the online conversation and get instant answers!