Place learning strategy of substantia nigra pars compacta-lesioned rats.
The substantia nigra pars compacta (SNc) and the dorsal striatum are often considered to be necessary for stimulus-response (S-R) habit learning, whereas the dorsal hippocampus is considered to be necessary for relational (declarative) memory. Spatial learning is a kind of relational learning that occurs when a rat is released from different locations (variable start) in a water maze to find a submerged platform that is kept in a constant location. However, when the rat is always released from the same starting position (constant start), it can learn to find the platform oriented by a fixed configuration of cues, that is, by S-R learning. To test the critical role of the SNc in S-R and relational learning, the authors tested adult male Wistar rats, sham-operated or with a lesion in the SNc, in these 2 versions of the water maze task. The SNc lesion was induced by bilateral intranigral infusion of 0.5 micromol 1-methyl-4-phenyl- 1,2,3,6-tetrahydropyridine. Although the SNc-lesioned rats learned the variable-start version as effectively as sham rats did, they were significantly impaired in learning the constant-start version of the task.
Da Cunha
Claudio
C
Departamento de Farmacologia, Universidade Federal do Paraná, Curitiba, PR, Brazil. dacunha@ufpr.br
Silva
Marcio H C
MH
Wietzikoski
Samantha
S
Wietzikoski
Evellyn C
EC
Ferro
Marcelo M
MM
Kouzmine
Ivana
I
Canteras
Newton S
NS
D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal; D015306:Biogenic Monoamines / Q000378:metabolism; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology*; D009498:Neurotoxins / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects; D013037:Spatial Behavior / Q000187:drug effects / Q000502:physiology*; D013378:Substantia Nigra / Q000293:injuries / Q000503:physiopathology*; D013550:Swimming; D013997:Time Factors
D015306:Biogenic Monoamines; D009498:Neurotoxins; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine