Effects of L-dopa methyl ester on the strabismic amblyopia cats / 中国药理学通报

Aim To observe the effects of the L-dopa methyl ester (LDME) on the pattern visual evoked potentials (P-VEP) and the expression of c-fos mRNA in neurons of the visual cortex of kittens with strabismic amblyopia, and explore the therapeutic effect of L-dopa methyl ester on amblyopia and its action mechanism.Methods 30 normal kittens were randomly divided into 6 groups: low dose of L-dopa methyl ester (20 mg·kg~(-1)), medium dose of L-dopa methyl ester (40 mg·kg~(-1)), and high dose of L-dopa methyl ester (80 mg·kg~(-1)),positive control (L-dopa 40 mg·kg~(-1)),normal control, and model control group.The surgery for producing iatrogenic convergent strabismus was performed on 4 weeks old kittens(normal control group excluded). After the confirmation of the development of amblyopia by pattern visual evoked potential,L-dopa methyl ester,L-dopa and normal saline were given to the corresponding animals, respectively. The P-VEP of amblyopia eyes was observed after one month, and the technique of in situ hybridization was used to detect the expression of c-fos mRNA.Results L-dopa methyl ester could reduce obviously the length of P100 peak latency of the cat strabismic amblyopes, and increase the amplitude of P100. The positive staining cells of strabismic cat visual cortex were less than those of normal cats, whose difference was significant (P<0.01).Positive staining cells in the treatment group were significantly increased when compared with that of the model group (P<0.01).Conclusion L-dopa methyl ester can significantly improve the conduction and sensory function in the model of strabismic amblyopia cats. The mechanism may be related to the increased amount of L-dopa methyl ester into the cerebral cortex and regulation of the expression of c-fos mRNA.

Effects of Coadministraion of (-)-3-PPP and Haloperidol on the c-fos Expression in the Nucleus Accumbens and Prefrontal Cortex of Rats / 대한정신약물학회지

OBJECTIVE: The purpose of our study was to measure and compare the c-fos mRNA expression patterns in the nucleus accumbens (NAS) and prefrontal cortex (PFC) of rats after the administration of haloperidol (2 mg/kg) or (-)-3-PPP (2 mg/kg) plus haloperidol (2 mg/kg). METHODS: Reverse transcriptase-polymerase chain reactions (RT-PCR) were performed on total RNA from samples of the NAS and PFC of rats to detect the expression of c-fos mRNA. As internal control, beta-actin mRNA was co-amplified. The products were separated by electrophoresis, and the density of bands was quantified using an image-analysis software. RESULTS: Both the administration of haloperidol (2 mg/kg) and (-)-3-PPP (2 mg/kg) plus haloperidol (2 mg/kg) increased the c-fos mRNA expression significantly (p<0.05) in the NAS, but had no effects in the PFC. In addition, the coadministration of (-)-3-PPP (2 mg/kg) and haloperidol (2 mg/kg) demonstrated more (0.05) remarkable c-fos mRNA expressions than those obtained with the administration of haloperidol (2 mg/kg) alone. CONCLUSION: These results suggest that the coadministration of (-)-3-PPP and haloperidol may have more potent antipsychotic effect compared to the administration of haloperidol alone.

C-fos mRNA Expression in Rat Hippocampal Neurons by Antidepressant Drugs

This study was designed to examine the effects of two antidepressant drugs on the expression of c-fos mRNA in cultured embryonic rat hippocampal neurons. The drugs used were imipramine and amitriptyline. On the fourth day of culture, hippocampal neurons were treated with variable concentrations of each drug. Competitive RT-PCR(Reverse Transcriptase-PCR) analysis was used to quantify the c-fos mRNA expression induced by each drug. Experimental results showed that acute and direct treatment with imipramine and amitriptyline with relatively low concentrations(imipramine or =100micrometer, amitriptyline > or =100micrometer) c-fos mRNA was not detected. These findings suggest the followings. Firstly, the action mechanisms of these drugs on the hippocampal neurons might not be mediated by c-fos but by other immediate-early genes(IEGs). Secondly, their actions may be mediated indirectly via other areas of the brain. Thirdly, the expression of c-fos might be inhibited by high concentrations of these drugs, or the high concentrations could induce cell death. Finally, though cell death remains to be confirmed, the inhibition of c-fos induction or cell death could play a role in the cognitive impairments known to be adverse effects of some antidepressants. This study is believed to be a first step toward understanding the mechanisms of learning and memory. Further studies are needed to investigate the expression of various IEGs and changes in the hippocampal neurons of rat resulting from chronic treatment with antidepressant drugs.

Effects of Deafferented Sensory Inputs on c-fos mRNA Expression in Medial Vestibular Nucleus of Rats Following Unilateral Labyrinthectomy / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Fos is a protein product of proto-oncogene c-fos, which is induced by various kinds of stimulations such as noxious, physiologic and electrical stimulations. In the vestibular system, there have been several evidences that c-fos was expressed in the brainstem vestibular nuclei during vestibular compensation following unilateral labyrinthectomy (ULX). In this study, the author evaluated the effect of deafferented sensory inputs on the c-fos mRNA expression in the medial vestibular nucleus of unilaterally labyrinthectomized rats. MATERIALS AND METHODS: Animals in the experimental group underwent tarsorraphy and cervical dorsal ganglionectomy to deprive them of visual and proprioceptive sensory inputs immediately after ULX, whereas the experimental group II did not receive any procedure after ULX. Expression of c-fos mRNA was demonstrated by in situ hybridization technique. All animals were sacrificed at 1, 3, 6, 9, 24, 48 hours after ULX and frozen sectioned tissues of brainstem were used in situ hybridization. RESULTS: Three hours after ULX, the expression of c- fos mRNA was increased in the dorsal portion of medial vestibular nucleus (dMVN) in both groups and after 6 hours of ULX, it was markedly reduced. In group I (deafferented), however, asymmetric expression was observed in 24 hours after the operation. In group II, the increased expression of c-fos mRNA in the ipsilateral dMVN continued until 9 hours after the operation and thereafter, the asymmetry of c-fos mRNA expressions between the ipsilateral and contralateral dMVN was decreased. CONCLUSION: These findings suggest that vision and proprioception influenced the expression of c-fos mRNA in the brainstem medial vestibular nucleus after ULX and corrected the asymmetric expression between the healthy and lesioned nuclei earlier than the deafferented group.

Systemic injection of lidocaine induce expression of c-fos mRNA and protein in adult rat brain

Both direct and indirect environmental stress to brain were increase the expression of transcription factor c-fos in various populations of neurons. In this study, we examined whether the intraperitoneal injections of lidocaine at doses inducing convulsion within 10 min increased the level of c-fos mRNA and protein in forebrain areas. In situ hybridization using (35S)UTP-labeled antisense c-fos, cRNA increased c-fos mRNA levels though hippocampal formation, piriform cortex, septum, caudate-putamen, neostriatum, and amygdala within 2 hr. In parallel with the mRNA expression, c-FOS protein immunoreactivity was also observed in the same forebrain areas. In contrast to the seizure activity and widespread neuronal degeneration following a kainate treatment, injections of lidocaine did not produce neuronal death within 3 days. The present study indicates that lidocaine induces convulsion and c-fos expression without causing neuro-toxicity.

ACUPUNCTURE EFFECT ON GENE EXPRESSION OF THE MOUSE PERITONEAL MACROPHAGE / 解剖学报

Objective To investigate the relationship between acupuncture analgesia and cellular immunity, the acupuncture effect on expression of c fos mRNA, ppENKmRNA,iNOSmRNA and iNOS activity in the mouse peritoneal macrophage were studied. Methods Twenty BALB/c mice were randomly divided into 2 groups:a,the acupuncture group treated with 5Hz electroacupuncture (EA); b, the control group treated with no EA. The pain threshold was detected by K + ionophoresis method before and after EA or restraining. The experiment was performed by using in situ hybridization, NADPH NBT histochemistry, RNA dot blot and protein dot blot techniques. All dot blot signals were scanned for statistical analysis. Results The hybridization signals and iNOS activity appeared as granules in bluish violet color, localized in the cytoplasm of the macrophage. All dot blot signals were increased in the acupuncture group, when compared with those in the control group( P