סמינר המחלקה להנדסה ביו רפואית

דר' יעל יניב

Cells within the sinoatrial node, the heart’s pacemaker, generate

spontaneous action potentials (APs) that are conducted to the ventricle

and excite ventricular myocyte contraction.

For several decades, the prevailing viewpoint on the heart’s pacemaker

activity has related heart rate and rhythm only to the surface membrane,

suggesting that activity is driven only by voltage-and time-dependent ion

channels (membrane clock). My recent experimental studies, however,

have shown discovered that the pacemaker membrane clock is tightly

coupled to the intracellular dynamics on a beat-to-beat basis. Moreover,

the mitochondria dynamically buffer cytosolic affecting the sarcoplasmic

reticulum load. The change in sarcoplasmic reticulum load translates into

change in the AP firing rate.

In my talk, I will present bioenergetics and systems biology perspectives

of the new coupled-clock pacemaker paradigm.