(2) The delta subthreshold rhythm's key feature is its highly variable cycle duration (frequency), resulting in minimal autocorrelation—a characteristic of quasiperiodic processes. Quasiperiodic rhythms could be prevalent in the brain, often eluding classical Fourier approaches for detection.
Ref: https://www.nature.com/articles/s41467-023-39497-z
Striatal cholinergic interneuron membrane voltage tracks locomotor rhythms in mice - Nature Communications
Behaviorally relevant neural rhythms have been mainly studied at the neural population level. Here, the authors show that subthreshold membrane voltage delta-frequency oscillations in individual striatal cholinergic neurons modulate spike timing, striatal network beta rhythmicity, and track patterned stepping movement.
(1) The activity of striatal cholinergic interneurons, also known as TAN neurons in monkeys, has been extensively studied. Spike Autocorrelograms are fast decaying with no clear rhythmic patterns (sidelobs), indicating absence of rhythm. However, using voltage imaging in awake mice, we've discovered a fascinating finding! Many of these neurons exhibit prominent delta rhythmic modulations in their subthreshold activity, easily detectable by visual inspection.
Voltage imaging of deep brain stimulation effects in the awake brain:
https://www.nature.com/articles/s41467-022-35314-1
Deep brain stimulation creates informational lesion through membrane depolarization in mouse hippocampus - Nature Communications
The neurophysiological mechanisms of deep brain stimulation remain poorly understood. Through fluorescence voltage imaging of individual hippocampal neurons in awake mice, the authors show that deep brain stimulation causes membrane depolarization that impairs a neuron’s ability to respond to intrinsic network activity patterns and optogenetic somatic depolarization, thereby creating an informational lesion.
Earl K. Miller