Changing Extracellular Ca2+ and Mg2+ to Normal elicits the Slow Oscillation
The extracellular concentrations of Ca2+ and Mg2+ in vivo are approximately 1 mM, and K+ is approximately 3.1 to 3.5 mM. However, traditional slice solutions have used abnormally high concentrations of Ca2+ (e.g. 2 mM) and Mg2+ (e.g. 2 mM). By changing the extracellular concentration of Ca2+, Mg2+ and K+ to NORMAL levels, we found that our visual or prefrontal cortical slices began to generate the slow oscillation, much as in the naturally sleeping or anesthetized animal. For this reason, we refer to these slices as "SLEEPING SLICES" similar to those we have studied of the thalamus.
In our research we are addressing the following questions on the slow oscillation:
- What are the cellular mechanisms for the generation of this activity?
- What are the functional consequences of spontaneous activity in the cortex?
- How do the ascending and descending neuromodulatory transmitter systems achieve their control over these patterns of activity?
- How do these different patterns of activity allow the CNS to generate seizures during certain states?