9/8/03
23
Equations
| F is increasing function of r and g |
|
| f1 is
increasing function of g |
|
| f2 is
decreasing function of g |
|
| NB rate at which receptors
are resensitized is proportional to fraction of desensitized receptors (1Ðr) |
|
| Laplacian: |
|
| Recall: second derivative is positive at a relative
minimum |
|
| Hence Laplacian is positive at a relative minimum |
|
| So chemical will diffuse into a rel. min. from
relatively higher surrounding concentrations |
|
| PDE: external
phosphodiesterase /fas fo dye ES ter ace?/, a protein that degrades cAMP |
|
| PDI: a protein that inhibits
PDE |
|
| Activity of PDE, ke
is not constant: ke(x,y,t) = ke,max
/ [1 + PDI(x,y,t)] |
|
| (P‡lsson & Cox) |