Spatial learning in rats is impaired by microinfusions of protein kinase C-gamma antisense oligodeoxynucleotide within the nucleus accumbens.
The nucleus accumbens (NAcc) has been shown to play a role in motor and spatial learning. Protein kinase C (PKC) has been implicated in the mechanisms of initiation and maintenance of long-term potentiation that is thought to be involved in the storage of long-term memory. In the present study, the importance of de novo synthesis of PKC-gamma within the NAcc in the acquisition and retention of spatial discrimination learning was assessed using an antisense knockdown approach. Separate groups of Long-Evans rats were exposed to acute microinfusions (6microg/microl) of PKC-gamma antisense oligodeoxynucleotide (AS-ODN), control oligodeoxynucleotide (C-ODN) or vehicle into the NAcc at 24 and 3h before each training session. Behavioral findings showed that the blockade of NAcc-PKC-gamma translation caused impairments in the early phase of learning and retention of spatial information. Biochemical experiments showed that PKC-gamma expression was reduced and Ca(2+)/phospholipid-dependent protein kinase C (PKC) activity was blocked significantly in the AS-ODN-treated rats in comparison with control rats. The present findings suggest that NAcc-PKC-gamma plays a role during the early acquisition of spatial learning. Also, retention test results suggest that NAcc-PKC-gamma may be working as an intermediate factor involved in the onset of molecular mechanisms necessary for spatial memory consolidation within the NAcc.
Alvarez-Jaimes
Lily
L
Department of Biology, University of Puerto Rico, Río Piedras Campus, P.O. Box 23360, San Juan 00931-3360, Puerto Rico.
Betancourt
Elba
E
Centeno-González
Marjorie
M
Feliciano-Rivera
Mara Z
MZ
Rodríguez
Danella
D
Peña de Ortíz
Sandra
S
Maldonado-Vlaar
Carmen S
CS
D000818:Animals; D003072:Cognition Disorders / Q000139:chemically induced; D015151:Immunoblotting; D007858:Learning / Q000187:drug effects*; D008297:Male; D008845:Microinjections; D009714:Nucleus Accumbens / Q000187:drug effects*; D020319:Oligodeoxyribonucleotides, Antisense / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D011493:Protein Kinase C / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D051381:Rats; D020318:Rats, Long-Evans; D013028:Space Perception / Q000187:drug effects*
D020319:Oligodeoxyribonucleotides, Antisense; C087857:protein kinase C gamma; D011493:Protein Kinase C