Synaptic mRNAs are modulated by learning.
We have recently demonstrated that brain plastic events significantly modify synaptic protein synthesis measured by the incorporation of [(35)S]methionine in brain synaptosomal proteins. Notably, in rats learning a two-way active avoidance task, the local synthesis of two synaptic proteins was selectively enhanced. Because this effect may be attributed to transcriptional modulation, we used reverse transcriptase-polymerase chain reaction methods to determine the content of discrete synaptosomal mRNAs in rats exposed to the same training protocol. Correlative analyses between behavioral responses and synaptosomal mRNA content showed that GAT-1 mRNA (a prevalent presynaptic component) correlates with avoidances and escapes in rat cerebellum, while glial fibrillary acid protein mRNA (an astrocytic component) correlates with freezings in cerebellum and cerebral cortex. These observations support the hypothesis that synaptic protein synthesis may be transcriptionally regulated. The cellular origin of synaptic transcripts is briefly discussed, with special regard to those present at large distances from neuron somas.
Ferrara
Eugenia
E
Department of Biological Sciences, University of Naples Federico II, Naples, Italy.
Cefaliello
Carolina
C
Eyman
Maria
M
De Stefano
Rosanna
R
Giuditta
Antonio
A
Crispino
Marianna
M
D000818:Animals; D001253:Astrocytes / Q000378:metabolism / Q000648:ultrastructure; D001362:Avoidance Learning / Q000502:physiology; D001522:Behavior, Animal / Q000502:physiology; D001921:Brain / Q000378:metabolism* / Q000648:ultrastructure; D002531:Cerebellum / Q000378:metabolism / Q000648:ultrastructure; D054022:Cerebrum / Q000378:metabolism / Q000648:ultrastructure; D050485:GABA Plasma Membrane Transport Proteins / Q000235:genetics*; D005904:Glial Fibrillary Acidic Protein / Q000235:genetics*; D007858:Learning / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000378:metabolism / Q000648:ultrastructure; D017729:Presynaptic Terminals / Q000378:metabolism* / Q000648:ultrastructure; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013574:Synaptosomes / Q000378:metabolism / Q000648:ultrastructure; D015533:Transcriptional Activation / Q000502:physiology
D050485:GABA Plasma Membrane Transport Proteins; D005904:Glial Fibrillary Acidic Protein; D012333:RNA, Messenger; C493415:Slc6a1 protein, rat