Biomedical Engineering Reference
In-Depth Information
in the closeup in Figure 3.2, eventually leading to an aggregate with 10
4
10
5
cells. After aggregation, the cells form a rudimentary multicellular organism,
cooperating via cell-cell contact, as well as chemical information exchange.
This later stage is more complicated and will not be discussed further in this
chapter.
−
Figure 3.2.
Close-up view of the aggregation center in experiments (C, D) and a
model (A,B; also E,F) due to Vasiev et al. [2]. The hole has been enhanced in going
from A to B and C to D by lowering the excitability of the system, accomplished
experimentally by adding caffeine. (courtesy of C. Weijer ). (See color insert.)
Given the aforementioned phenomenology, there are many questions that
are worth addressing with the help of mathematical models. First, we would
like to understand the signaling system responsible for the cAMP relay dynam-
ics underlying the waves. This will then allow us to explain how the wavefield
is able to organize itself so as to create the desired spatial information. Next,
we would like to understand the mechanism that enables the chemotactic re-
sponse. This requires modeling how the receptor occupancy data is processed,
via a spatially-extended reaction network, to lead to a symmetry-breaking
