Impairments of search behaviour in rats after haloperidol treatment, hippocampal or neocortical damage suggest a mesocorticolimbic role in cognition.
In a radial maze rats with fimbria-fornix or hippocampal damage are reported to show a lasting impairment of working but not reference memory (Olton, Becker and Handelman, 1979). On a 16-hole board, search task, rats with hippocampal damage showed deficits persisting over 100 trials on both measures: (4/16 holes contained food; working memory error - visit to a just-visited, baited hole; reference memory error - visit to a hole that had never been baited). Haloperidol treatment had no effect on the poor performance following hippocampal damage, but it impaired that of sham-controls on both measures. Animals with neocortical damage were impaired on the measure of reference memory alone, after haloperidol treatment. These measures may reflect two different information processing mechanisms. The hippocampus, the  overlying neocortex and the dopaminergic, mesocorticolimbic system seem to be differentially involved. The possibility that these mechanisms could relate to attention or memory and their importance for the study of the associative impairment of psychotic human subjects is briefly discussed.
D000818:Animals; D003071:Cognition / Q000502:physiology*; D005625:Frontal Lobe / Q000502:physiology*; D006220:Haloperidol / Q000494:pharmacology*; D006624:Hippocampus / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology; D008636:Mesencephalon / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D009949:Orientation / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012688:Septum Pellucidum / Q000502:physiology
D006220:Haloperidol