Effects of cholinergic depletion on neural activity in different laminae of the rat barrel cortex

The purpose of these experiments was to determine the effects of cholinergi c depletion on spontaneous and evoked activity of neurons in the different layers of the posteromedial barrel subfield (PMBSF) of the rat somatosensor y cortex. Acetylcholine neurons in nucleus basalis of Meynert (NBM) were se lectively lesioned with an immunotoxin (IT), 192 IgG-saporin. Spontaneous a ctivity was significantly lower in layers II-III, Va, and VI in IT-injected animals compared to control animals. Evoked activity was significantly low er in layers II-III, IV, Vb, and VI of IT-injected animals compared to cont rol animals. The largest difference was observed in layer Vb. Thus, choline rgic depletion causes significant changes in the magnitude of spontaneous a nd evoked activity but these differences are not completely in register wit h one another. (C) 2000 Elsevier Science B.V. All rights reserved.