Different Effects on Learning Ability After Injection of the Cholinergic Immunotoxin ME20.4IgG-Saporin Into the Diagonal Band of Broca, Basal Nucleus of Meynert, or Both in Monkeys

• Published in: Behavioral neuroscience 1999-04, Vol.113 (2), p.303-315
• Main Authors: Ridley, R. M, Barefoot, H. C, Maclean, C. J, Pugh, P, Baker, H. F
• Format: Article
• Language: English
• Subjects: Analysis of Variance; Anatomical correlates of behavior; Animal; Animals; Antibodies, Monoclonal; Behavioral psychophysiology; Biological and medical sciences; Brain damage; Brain Injuries - chemically induced; Callithrix; Cholinergic Agents; Cholinergic Blocking Drugs; Cholinergic Nerves; Cognition; Discrimination Learning; Discrimination Learning - drug effects; Discrimination Learning - physiology; Dizocilpine Maleate - pharmacology; Excitatory Amino Acid Antagonists - pharmacology; Female; Frontal Lobe - injuries; Frontal Lobe - pathology; Frontal Lobe - physiology; Fundamental and applied biological sciences. Psychology; Immune system; Immunotoxin; Immunotoxins; Learning; Male; Monkeys; Monkeys & apes; N-Glycosyl Hydrolases; N-Methyl-D-Aspartate; Neural Lesions; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Recovery of Function; Ribosome Inactivating Proteins, Type 1; Saporins; Visual Discrimination; Visual Perception - drug effects; Visual Perception - physiology
• ISSN: 0735-7044; 1939-0084
• DOI: 10.1037/0735-7044.113.2.303

Immunotoxic lesions of the diagonal band of Broca (VDB) in monkeys disrupted cholinergic input to the hippocampus, producing impaired learning of visuospatial conditional discriminations but not simple visual discriminations. Immunotoxic lesions of the basal nucleus of Meynert (NBM) deprived the cortex of most of its cholinergic input, producing impaired learning of simple visual discriminations but not visuospatial conditional discriminations. Combined lesions of the NBM + VDB resulted in impaired learning of both types of task. The impairment after NBM lesions ameliorated with time but could be reinstated by a low dose of the glutamate blocking drug MK801, which, at this dose, did not impair simple visual discrimination learning in normal monkeys. The cholinergic projections from the NBM and VDB may sustain the function of the glutamatergic pyramidal cell pathways within the cortex and hippocampus, respectively.