Egr-1 antisense oligodeoxynucleotide administration into the olfactory bulb impairs olfactory learning in the greater short-nosed fruit bat Cynopterus sphinx.
Postsynaptic densities (PSDs) contain proteins that regulate synaptic transmission. We examined two important examples of these, calcium/calmodulin-dependent protein kinase II (CaMKII) and PSD-95, in regard to the functional role of early growth response gene-1 (egr-1) in regulation of olfactory learning in the greater short-nosed fruit bat Cynopterus sphinx (family Pteropodidae). To test whether activation of egr-1 in the olfactory bulb (OB) is required for olfactory memory of these bats, bilaterally canulated individuals were infused with antisense (AS) or non-sense (NS)-oligodeoxynucleotides (ODN) of egr-1, or with phosphate buffer saline (PBS), 2h before the olfactory training. Our results showed that behavioral training significantly up-regulates immediate early gene (IEG) EGR-1 and key synaptic proteins Synaptotagmin-1(SYT-1), CaMKII and PSD-95, and phosphorylation of CaMKII in the OB at the protein level per se. Subsequently, we observed that egr-1 antisense-ODN infusion in the OB impaired olfactory memory and down regulates the expression of CaMKII and PSD-95, and the phosphorylation of CaMKII but not SYT-1. In contrast, NS-ODN or PBS had no effect on the expression of the PSDs CaMKII or PSD-95, or on the phosphorylation of CaMKII. When the egr-1 NS-ODN was infused in the OB after training for the novel odor there was no effect on olfactory memory. These findings suggest that egr-1 control the activation of CaMKII and PSD-95 during the process of olfactory memory formation.
Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, India.
Ambigapathy
A
Ganesh
Wieslaw
W
Bogdanowicz
Krishnaswamy
K
Balamurugan
Durairaj
D
Ragu Varman
Koilmani Emmanuvel
KE
Rajan
D015116:5,7-Dihydroxytryptamine / Q000494:pharmacology; D000818:Animals; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000378:metabolism; D002685:Chiroptera; D004305:Dose-Response Relationship, Drug; D051766:Early Growth Response Protein 1 / Q000737:chemistry / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D007859:Learning Disabilities / Q000139:chemically induced* / Q000188:drug therapy / Q000503:physiopathology*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009812:Odorants; D009830:Olfactory Bulb / Q000187:drug effects*; D020319:Oligodeoxyribonucleotides, Antisense / Q000633:toxicity*; D021641:Recognition, Psychology / Q000187:drug effects*; D012153:Retention, Psychology / Q000187:drug effects; D018490:Serotonin Agents / Q000494:pharmacology; D012903:Smell / Q000187:drug effects*; D050863:Synaptotagmin I / Q000378:metabolism; D013997:Time Factors
D051766:Early Growth Response Protein 1; D009419:Nerve Tissue Proteins; D020319:Oligodeoxyribonucleotides, Antisense; D018490:Serotonin Agents; D050863:Synaptotagmin I; C033652:postsynaptic density proteins; D015116:5,7-Dihydroxytryptamine; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2