Differential gene expression in the rat hippocampus during learning of an operant conditioning task.
Changes in transcription levels of brain-derived neurotrophic factor (BDNF), cyclic adenosine monophosphate (cAMP) response element binding (CREB), Synapsin I, Ca(2+)/calmodulin-dependent protein kinase II (CamKII), activity-regulated cytoskeleton-associated protein (Arc), c-jun and c-fos have been associated to several learning paradigms in different brain areas. In this study, we measured mRNA expression in the hippocampus by real time (RT)-PCR mRNA levels of BDNF, CREB, Synapsin I, CamKII, Arc, c-jun and c-fos, during learning and operant conditioning task. Experimental groups were as follows: control (C, the animals never left the bioterium), when the animals reached 50-65% of the expected response (Incompletely Trained, IT), when animals reached 100% of the expected response with a latency time lower than 5 s (Trained, Tr), Box Control of Incompletely Trained (BCIT), animals spent the same time as the IT in the operant conditioning box and Box Control of Trained (BCTr) animals spent the same time as the Tr in the operant conditioning box. All rats were killed at the same time by cervical dislocation 15 min after training and hippocampi were removed and processed. We found increments of mRNA levels of most genes (BDNF, CREB, Synapsin I, Arc, c-jun and c-fos) in IT and Tr groups compared to their box controls, but increments in Tr were smaller compared with IT. These results describe a differential gene expression in the rat hippocampus when the animals are learning and when animals have already learned. Taking together the results presented herein with the known functions of these genes, we propose a link between changes in gene expression in the hippocampus and different degrees of cellular activation and plasticity during learning of an operant conditioning task.
Rapanelli
M
M
IBYME-CONICET, Laboratorio de Biologia del Comportamiento, Vuelta de Obligado 2490, Ciudad de Buenos Aires, Buenos Aires, Argentina. rapanelli@dna.uba.ar
Frick
L R
LR
Zanutto
B S
BS
D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000235:genetics / Q000378:metabolism; D003216:Conditioning, Operant / Q000502:physiology*; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006624:Hippocampus / Q000502:physiology*; D007858:Learning / Q000502:physiology*; D008297:Male; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D016704:Synapsins / Q000235:genetics / Q000378:metabolism; D013997:Time Factors
D019208:Brain-Derived Neurotrophic Factor; C508137:Creb1 protein, rat; D017362:Cyclic AMP Response Element-Binding Protein; D003598:Cytoskeletal Proteins; D009419:Nerve Tissue Proteins; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D016704:Synapsins; C092069:activity regulated cytoskeletal-associated protein; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2