Figure 3.

Local application of carbachol into the P-wave generator induced state-independent P-waves during SWS. Sample polygraphic signs of SWS after a session of learning training trials followed by microinjection of control saline (A) or microinjection of carbachol (B) into the P-wave generator. Note the qualitative similarity in both records showing characteristic electroencephalographic signs of SWS: high amplitude, low-frequency waves recorded from the frontal cortex (EEG), reduced muscle tone recorded from the neck (EMG), absence of eye movements (EOG), and non-theta-type EEG recorded from the hippocampus (HPC). Despite qualitative similarity, microinjection of carbachol into the P-wave generator (B) induced P-waves (PON) that are normally absent during SWS without cholinergic activation of the P-wave generator (A).