Activity-dependent expression of miR-132 regulates immediate-early gene induction during olfactory learning in the greater short-nosed fruit bat, Cynopterus sphinx.
The activity-dependent expression of immediate-early genes (IEGs) and microRNA (miR)-132 has been implicated in synaptic plasticity and the formation of long-term memory (LTM). In the present study, we show that olfactory training induces the expression of IEGs (EGR-1, C-fos, C-jun) and miR-132 at similar time scale in olfactory bulb (OB) of Cynopterus sphinx. We examined the role of miR-132 in the OB using antisense oligodeoxynucleotide (AS-ODN) and demonstrated that a local infusion of AS-ODN in the OB 2h prior to training impaired olfactory memory formation in C. sphinx. However, the infusion of AS-ODN post-training did not cause a deficit in memory formation. Furthermore, the inhibition of miR-132 reduced the olfactory training-induced expression of IEGs and post synaptic density protein-95 (PSD-95) in the OB. Additionally, we show that miR-132 regulates the activation of calcium/calmodulin-dependent protein kinase-II (CaMKII) and cAMP response element binding protein (CREB), possibly through miR-148a. These data suggest that olfactory training induces the expression of miR-132 and IEGs, which in turn activates post-synaptic proteins that regulate olfactory memory formation.
Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, India.
Murugan
M
Mukilan
Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, India.
Durairaj
D
Ragu Varman
Department of Biotechnology, Manonmaniam Sundaranar University, Tirunelveli 627012, India.
Sivasubramaniam
S
Sudhakar
Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, India. Electronic address: emmanuvel1972@yahoo.com.
Koilmani Emmanuvel
KE
Rajan
D000818:Animals; D002685:Chiroptera / Q000502:physiology*; D015870:Gene Expression / Q000502:physiology; D017781:Genes, Immediate-Early / Q000502:physiology*; D007858:Learning / Q000502:physiology*; D008568:Memory / Q000502:physiology; D035683:MicroRNAs / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000502:physiology; D060888:Real-Time Polymerase Chain Reaction; D012153:Retention, Psychology / Q000502:physiology; D012903:Smell / Q000502:physiology*
D035683:MicroRNAs; D009419:Nerve Tissue Proteins; C033652:postsynaptic density proteins
CREB; Cynopterus sphinx; Immediate-early genes; Olfactory memory; miR-132