Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A model for the generation of localized transient Na+ elevations in
  vascular smooth muscle   We present a stochastic computational model to study the mechanism of
signalling between a source and a target ionic transporter, both localized on
the plasma membrane (PM) and in intracellular nanometre-scale subplasmalemmal
signalling compartments comprising the PM, the sarcoplasmic reticulum (SR),
Ca2+ and Na+ transporters, and the intervening cytosol. We refer to these
compartments, sometimes called junctions, as cytoplasmic nanospaces or
nanodomains. In the chain of events leading to Ca2+ influx for SR reloading
during asynchronous Ca2+ waves in vascular smooth muscle (VSM), the physical
and functional link between non-selective cation channels (NSCC) and Na+/Ca2+
exchangers (NCX) needs to be elucidated in view of two recent findings: the
identification of the transient receptor potential canonical channel 6 (TRPC6)
as a crucial NSCC in VSM cells and the observation of localized cytosolic [Na+]
transients following purinergic stimulation of these cells. Having previously
helped clarify the Ca2+ signalling step between NCX and SERCA behind SR Ca2+
refilling, this quantitative approach now allows us to model the upstream
linkage of NSCC and NCX. We have implemented a random walk (RW) Monte Carlo
(MC) model with simulations mimicking a Na+ diffusion process originating at
the NSCC within PM-SR junctions. The model calculates the average [Na+] in the
nanospace and also produces [Na+] profiles as a function of distance from the
Na+ source. Our results highlight the necessity of a strategic juxtaposition of
the relevant signalling channels as well as other physical structures within
the nanospaces to permit adequate [Na+] build-up to provoke NCX reversal and
Ca2+ influx to refill the SR.

33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin