31 Acetylcholine (ACh), acting at muscarinic ACh receptors (mAChRs), modulates the 32 excitability and synaptic connectivity of hippocampal pyramidal neurons. CA1 pyramidal 33 neurons respond to transient (" phasic ") mAChR activation with biphasic responses in 34 which inhibition is followed by excitation, whereas prolonged (" tonic ") mAChR activation 35 increases CA1 neuron excitability. Bot...
