Selective immunolesions of CH4 cholinergic neurons do not disrupt spatial memory in rats.
Adult male Long-Evans rats were subjected to bilateral lesions of the cholinergic neurons in the nucleus basalis magnocellularis (NBM) by injection of 0.2 or 0.4 microg 192-IgG-saporin in 0.4 microl phosphate-buffered saline. Control rats received an equivalent amount of phosphate-buffered saline. Starting 2 weeks after surgery, all rats were tested for locomotor activity in their home cage, beam-walking performance, T-maze alternation rates (working memory), reference and working memory performance in a water-maze task, and memory capabilities in the eight-arm radial maze task using uninterrupted and interrupted (delay of 2 min, 2 h and 6 h after four arms had been visited) testing procedures. Histochemical analysis showed a significant decrease of acetylcholinesterase (AChE)-positive reaction products (30-66%) in various cortical regions at the 0.2-microg dose. At the dose of 0.4 microg, there was an additional, although weak, damage to the hippocampus (17-30%) and the cingulate cortex (34%). The behavioral results showed only minor impairments in spatial memory tasks, and only during initial phases of the tests (reference memory in the water maze, working memory in the radial maze). The behavioral effects of the dramatic cholinergic lesions do not support the idea of a substantial implication of cholinergic projections from the NBM to the cortex in the memory processes assessed in this study, but they remain congruent with an involvement of these projections in attentional functions.
Galani
Rodrigue
R
Laboratoire de Neurosciences Comportementales et Cognitives, LN2C UMR 7521, Université Louis Pasteur/CNRS-IFR 37, 12 rue Goethe, F-67000 Strasbourg, France. rodrigue.galani@psycho-ulp.u-strasbg.fr
Lehmann
Olivia
O
Bolmont
Tristan
T
Aloy
Elizabeth
E
Bertrand
Fabrice
F
Lazarus
Christine
C
Jeltsch
Hélène
H
Cassel
Jean-Christophe
JC
D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal / Q000633:toxicity; D001522:Behavior, Animal / Q000502:physiology; D001921:Brain / Q000033:anatomy & histology / Q000201:enzymology; D020667:Diagonal Band of Broca / Q000166:cytology / Q000502:physiology*; D006651:Histocytochemistry; D007150:Immunohistochemistry; D000922:Immunotoxins / Q000633:toxicity; D008297:Male; D018782:Maze Learning / Q000502:physiology; D008568:Memory / Q000502:physiology; D008570:Memory, Short-Term / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology; D009699:N-Glycosyl Hydrolases; D009474:Neurons / Q000201:enzymology / Q000502:physiology*; D010275:Parasympathetic Nervous System / Q000166:cytology / Q000201:enzymology / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D051381:Rats; D020318:Rats, Long-Evans; D054789:Ribosome Inactivating Proteins, Type 1; D000076985:Saporins; D013028:Space Perception / Q000502:physiology*
C085696:192 IgG-saporin; D000911:Antibodies, Monoclonal; D000922:Immunotoxins; D054789:Ribosome Inactivating Proteins, Type 1; D000110:Acetylcholinesterase; D009699:N-Glycosyl Hydrolases; D000076985:Saporins