Persistent activity in layer 5 pyramidal neurons following cholinergic activation of mouse primary cortices

Persistent spiking activity is thought to be a cellular process involved in working memory. We have been interested in whether persistent activity also exists in cortical areas which are not involved in this memory process. To study the possible presence and the mechanisms of persistent activity in layer 5 pyramidal cells of the mouse primary somatosensory, visual and motor cortices, we used patch-clamp and calcium imaging techniques. A combination of cholinergic receptor activation and suprathreshold depolarization or sufficient extracellular stimulation leads to either a subthreshold afterdepolarization or suprathreshold persistent activity in these cortices. There is a continuum of respo…