Electrical stimulation of the horizontal limb of the diagonal band of Broca modulates population EPSPs in piriform cortex

Electrical stimulation of the horizontal limb of the diagonal band of Broca modulates population EPSPs in piriform cortex. J. Neurophysiol,. 81: 2737- 2742, 1999. Electrical stimulation of the horizontal limb of the diagonal b and of Broca (HDB) was coupled with recording of evoked potentials in the p iriform cortex. Stimulation of the HDB caused an enhancement of the late, d isynaptic component of the evoked potential elicited by stimulation of the lateral olfactory tract but caused a suppression of the synaptic potential elicited by stimulation of the posterior piriform cortex. The muscarinic an tagonist scopolamine blocked both effects of HDB stimulation. The enhance m ent of disynaptic potentials could be due to cholinergic depolarization of pyramidal cells, whereas the suppression of potentials evoked by posterior piriform stimulation could be due to presynaptic inhibition of intrinsic fi ber synaptic transmission by acetylcholine.