Slide 10

These, and other recordings, reveal that both thalamocortical and thalamic reticular neurons exhibit two states of activity: rhythmic burst firing at hyperpolarized membrane potentials and tonic firing at depolarized membrane potentials. Interestingly, thalamocortical neurons burst at 0.5 to 4 Hz, which is in the frequency range of delta waves, while thalamic reticular neurons rhythmically burst at 0.5 to 12 Hz, which spans the frequency ranges of both delta and spindle waves.

These findings are in the following references:

• Bal, T. and McCormick, D.A. (1992) Mechanisms of oscillatory activity in guinea-pig nucleus reticularis thalami in vitro: a mammalian pacemaker. Journal of Physiology 468: 669-691.
• McCormick, D.A. and Pape, H.C. Properties of a hyperpolarization-activated cation current and its role in rhythmic oscillation in thalamic relay neurons. Journal of Physiology (1990) 431: 291-318.