Resetting behavior in a model of bursting in secretory pituitary cells: distinguishing plateaus from pseudo-plateaus.
Bull Math Biol
; 70(1): 68-88, 2008 Jan.
Article
em En
| MEDLINE
| ID: mdl-17703340
ABSTRACT
We study a recently discovered class of models for plateau bursting, inspired by models for endocrine pituitary cells. In contrast to classical models for fold-homoclinic (square-wave) bursting, the spikes of the active phase are not supported by limit cycles of the frozen fast subsystem, but are transient oscillations generated by unstable limit cycles emanating from a subcritical Hopf bifurcation around a stable steady state. Experimental time courses are suggestive of such fold-subHopf models because the spikes tend to be small and variable in amplitude; we call this pseudo-plateau bursting. We show here that distinct properties of the response to attempted resets from the silent phase to the active phase provide a clearer, qualitative criterion for choosing between the two classes of models. The fold-homoclinic class is characterized by induced active phases that increase towards the duration of the unperturbed active phase as resets are delivered later in the silent phase. For the fold-subHopf class of pseudo-plateau bursting, resetting is difficult and succeeds only in limited windows of the silent phase but, paradoxically, can dramatically exceed the native active phase duration.
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Base de dados:
MEDLINE
Assunto principal:
Hipófise
/
Modelos Biológicos
Tipo de estudo:
Prognostic_studies
/
Qualitative_research
Limite:
Animals
Idioma:
En
Revista:
Bull Math Biol
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Estados Unidos