Subthreshold membrane potential oscillations

These oscillations, which resembled sinusoidal wave forms, were originally discovered in the mammalian inferior olive nucleus cells.

[9] They have also been described and studied in layers V of the entorhinal cortex,[10][11][12] the inferior olive in vivo,[13] the olfactory bulb[14] and the dorsal cochlear nucleus.

[16][17] Based on the analysis done by Bohemer et al., the hypothalamic supraoptic nucleus (SON) contains two major populations of magnocellular neurosecretory neurons which produces and secretes vasopressin and oxytocin, respectively.

[18] The study examined electrophysiological properties and ionic bases of subthreshold oscillation of the membrane potential in 104 magnocellular neurons of rats, using intracellular recording techniques.

The study found that SMOP that occurred in all neurons examined were voltage-dependent; oscillation was not a result of excitatory or inhibitory activity and neither was it from an electric coupling.

[18] This suggests that the subthreshold oscillation of the membrane potential may be crucial for inter-neuronal synchronization of discharge and for the amplification of synaptic events.

For example, a study examined the frequencies of SMPO in different anatomical positions on the dorsoventral axis of a rat medial entorhinal cortex.

[6] Which means that the inferior olive of mammals’ brain exhibits relatively stable frequencies settings of oscillations.

[2] This subthreshold activity is responsible for shaping circuits for maturation and are especially distinct in the retina, in the form of retinal waves.

[2] In the olfactory system, responsible for sense of smell, according to the study, subthreshold membrane potential oscillations present in mitral cells, which are neurons in the olfactory system, are said to influence the timing of the spikes of action potentials, which in turn allows for the synchronization of multiple mitral cells.