TY - JOUR
T1 - Removal of cholinergic input to rat posterior parietal cortex disrupts incremental processing of conditioned stimuli
AU - Bucci, David J.
AU - Holland, Peter C.
AU - Gallagher, Michela
PY - 1998/10/1
Y1 - 1998/10/1
N2 - Recent research suggests that the basal forebrain cholinergic neurons innervating the cortex play a role in attentional functions in both primates and rodents. Among the cortical targets of these projections in primates is the posterior parietal cortex (PPC), a region shown to be critically involved in the regulation of attention. Recent anatomical studies have defined a cortical region in the rat that may be homologous to the PPC of primates. In the present study, cholinergic innervation of the PPC was depleted by intracortical infusion of the immunotoxin 192 IgG-saporin. Control and lesioned rats were then tested in two associative learning paradigms designed to increase attentional processing of conditioned stimuli (CSs). In one experiment, attention was manipulated by shifting a predictive relation between a light CS and another CS to a less predictive relation. Unlike control rats, lesioned rats failed to increase attention when the predictive relation was modified. In a second experiment, attentional processing of a tone CS was increased when its introduction during training coincided with a change in the value of the unconditioned stimulus, a phenomenon referred to as unblocking. Unlike control rats, lesioned rats failed to exhibit unblocking. In both paradigms, lesioned rats conditioned normally when the training procedures did not encourage increased attentional processing. These findings, across different behavioral paradigms and stimulus modalities, provide converging evidence that intact cholinergic innervation of the PPC is important for changes in attention that can increase the processing of certain cues.
AB - Recent research suggests that the basal forebrain cholinergic neurons innervating the cortex play a role in attentional functions in both primates and rodents. Among the cortical targets of these projections in primates is the posterior parietal cortex (PPC), a region shown to be critically involved in the regulation of attention. Recent anatomical studies have defined a cortical region in the rat that may be homologous to the PPC of primates. In the present study, cholinergic innervation of the PPC was depleted by intracortical infusion of the immunotoxin 192 IgG-saporin. Control and lesioned rats were then tested in two associative learning paradigms designed to increase attentional processing of conditioned stimuli (CSs). In one experiment, attention was manipulated by shifting a predictive relation between a light CS and another CS to a less predictive relation. Unlike control rats, lesioned rats failed to increase attention when the predictive relation was modified. In a second experiment, attentional processing of a tone CS was increased when its introduction during training coincided with a change in the value of the unconditioned stimulus, a phenomenon referred to as unblocking. Unlike control rats, lesioned rats failed to exhibit unblocking. In both paradigms, lesioned rats conditioned normally when the training procedures did not encourage increased attentional processing. These findings, across different behavioral paradigms and stimulus modalities, provide converging evidence that intact cholinergic innervation of the PPC is important for changes in attention that can increase the processing of certain cues.
KW - 192 IgG-saporin
KW - Acetylcholine
KW - Associative learning
KW - Attention
KW - Cholinergic basal forebrain
KW - Immunotoxin
KW - Posterior parietal cortex
KW - Rats
UR - http://www.scopus.com/inward/record.url?scp=0032189611&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032189611&partnerID=8YFLogxK
U2 - 10.1523/jneurosci.18-19-08038.1998
DO - 10.1523/jneurosci.18-19-08038.1998
M3 - Article
C2 - 9742170
AN - SCOPUS:0032189611
SN - 0270-6474
VL - 18
SP - 8038
EP - 8046
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 19
ER -