In most organisms, the physiology and behaviour are regulated by the circadian rhythms. These rhythms are controlled by a master clock which is called suprachiasmatic nucleus (SCN). In the SCN, it has been shown that there are two categories of neurons, per1 and non-per1 neurons. Per1 neurons express period (per1) gene which plays a key role in the molecular mechanism of the master clock while non-per1 neurons do not express per1 gene.
A previous experiment illustrated that per1 neurons have different behaviour over a day- night cycle from non-per1 neurons. It revealed that during the afternoon per1 neurons are divided into two groups: GA shows low amplitude oscillations (LAOs) while GB is in quiescence state (Q).
In this talk I will focus on modelling the two behaviours of per1 neurons, LAOs and Q, in the afternoon. Before modelling these behaviours I will discuss some general aspects of bifurcation which represent the main base for the work. Then I will present the mathematical model of per1 neurons and some interesting properties about the behavoiur of these neurons in the afternoon.