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.
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.
Ridley
R M
RM
Department of Experimental Psychology, University of Cambridge, United Kingdom. rmr21@cus.cam.ac.uk
Barefoot
H C
HC
Maclean
C J
CJ
Pugh
P
P
Baker
H F
HF
D000704:Analysis of Variance; D000818:Animals; D000911:Antibodies, Monoclonal; D001930:Brain Injuries / Q000139:chemically induced; D002144:Callithrix; D018678:Cholinergic Agents; D003071:Cognition; D004193:Discrimination Learning / Q000187:drug effects / Q000502:physiology*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005260:Female; D005625:Frontal Lobe / Q000293:injuries / Q000473:pathology* / Q000502:physiology*; D000922:Immunotoxins; D008297:Male; D009699:N-Glycosyl Hydrolases; D020127:Recovery of Function; D054789:Ribosome Inactivating Proteins, Type 1; D000076985:Saporins; D014796:Visual Perception / Q000187:drug effects / Q000502:physiology
D000911:Antibodies, Monoclonal; D018678:Cholinergic Agents; D018691:Excitatory Amino Acid Antagonists; D000922:Immunotoxins; C108575:ME20.4 IgG-saporin; D054789:Ribosome Inactivating Proteins, Type 1; D016291:Dizocilpine Maleate; D009699:N-Glycosyl Hydrolases; D000076985:Saporins