title: Changes in mRNA for post-synaptic density-95 (PSD-95) and carboxy-terminal PDZ ligand of neuronal nitric oxide synthase following facial nerve transection.
abstract: When the axon of motoneurons is transected, the number of synaptic boutons contacting the cell body is decreased, and the recovery of synapses depends on muscle reinnervation. Post-synaptic density-95 (PSD-95) is a protein which is located at the post-synaptic density (PSD) and it plays a pivotal role in regulating synaptic plasticity and synaptogenesis. In addition, PSD-95 binds with neuronal nitric oxide synthase (nNOS), which is competitively inhibited by carboxy-terminal PDZ ligand of nNOS (CAPON) and, thereby, nNOS activity is thought to be regulated by PSD-95 and CAPON. We investigated the changes in mRNA for PSD-95, CAPON and nNOS in the facial motor nucleus of adult rats following axotomy, by in situ hybridization, in combination with the time course of muscle reinnervation, by retrograde tracing and nNOS protein expression, by examining nicotinamide adenine nucleotide phosphate diaphorase (NADPH-d) activity. Signals of mRNA for PSD-95 and CAPON were initially expressed in the facial motoneurons, transiently decreased following axotomy and gradually recovered to the control level. When reinnervation of the axotomized nerve into muscle was observed, mRNA expression of PSD-95 and CAPON started to recover in the facial motoneurons. It was also found that mRNA and protein expression of nNOS started to increase in the axotomized facial motoneurons just prior to the recovery of mRNA expression of PSD-95 and CAPON. These results suggest that PSD-95 and CAPON are involved in synaptogenesis and/or recovery of synaptic function in motoneurons after axotomy.
authors.affiliation: Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Japan. che@anat2.med.osaka-u.ac.jp
authors.forename: Y H
authors.initials: YH
authors.lastname: Che
authors.forename: M
authors.initials: M
authors.lastname: Tamatani
authors.forename: M
authors.initials: M
authors.lastname: Tohyama
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D019771:Axotomy; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D008058:Dihydrolipoamide Dehydrogenase / Q000032:analysis; D000076122:Disks Large Homolog 4 Protein; D005154:Facial Nerve / Q000502:physiology*; D051528:Guanylate Kinases; D017403:In Situ Hybridization; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009416:Nerve Regeneration; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D009474:Neurons / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000235:genetics* / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I; D012333:RNA, Messenger / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014158:Transcription, Genetic
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D000076122:Disks Large Homolog 4 Protein; C501447:Dlg4 protein, mouse; C501449:Dlg4 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C488082:NOS1AP protein, rat; D009419:Nerve Tissue Proteins; C110667:Nos1ap protein, mouse; D012333:RNA, Messenger; C033652:postsynaptic density proteins; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat; D008058:Dihydrolipoamide Dehydrogenase; D051528:Guanylate Kinases