CONTRIBUTION A L'ETUDE DU DELAI D'ACTION DES ANTIDEPRESSEURS (EFFETS DE TRAITEMENTS CHRONIQUES PAR DES ANTIDEPRESSEURS SUR LE TRANSPORTEUR VESICULAIRE DES MONOAMINES, LA TYROSINE HYDROXYLASE, LES RECEPTEURS OPIOIDES ET ET LE RECEPTEUR ORL 1 DE LA NOCICEPTINE CHEZ LE RAT)

ROUEN-BU Sciences (764512102) / SudocSudocFranceF

Le système nociceptine/récepteur NOP (Implication dans le mode d'action des antidépresseurs, dans la dépression et l'anxiété, et relations avec le système sérotoninergique)

ROUEN-BU Sciences (764512102) / SudocROUEN-BU Sciences Madrillet (765752101) / SudocSudocFranceF

A chronic treatment with fluoxetine decreases 5-HT(1A) receptors labeling in mice selected as a genetic model of helplessness

Two lines of mice were bred for their opposite helpless behavior in the tail suspension test, i.e., helpless (HL) mice and non helpless (NHL) mice. The 5-HT(1A) receptor labeling was quantified by means of autoradiography with (3)H-8-OH-DPAT on brain sections from mice of these two lines. We observed a significantly higher level of (3)H-8-OH-DPAT binding sites density in HL mice comparatively to NHL mice, in the medial prefrontal, cingulate, motor and sensorial cortices, in several regions of the limbic system, such as CA3 field of hippocampus, dentate gyrus, medial and baso-medial amygdala, and in dorsal and median raphe nuclei. A chronic 21-day treatment with the antidepressant fluoxetine (10 mg/kg, i.p. daily) attenuated significantly the spontaneous helplessness in HL mice but did not alter the behavior of NHL mice. In the brain of HL mice chronically injected with fluoxetine, the elevated (3)H-8-OH-DPAT binding sites density was no longer observed after treatment in several regions, among which the raphe nuclei. Conversely, the antidepressant treatment did not modify the (3)H-8-OH-DPAT binding sites density in NHL mice. The variation of 5-HT(1A) receptors binding density in the HL mice in response to a chronic fluoxetine treatment parallels the attenuation of the spontaneous helplessness observed in the tail suspension test, and may underlie this behavior

Why considering sexual differences is necessary when studying encephalopathy of prematurity through rodent models

International audienc

Age-Dependent Neonatal Intracerebral Hemorrhage in Plasminogen Activator Inhibitor 1 Knockout Mice

International audienc

Acute and subchronic treatments with selective serotonin reuptake inhibitors increase Nociceptin/Orphanin FQ (NOP) receptor density in the rat dorsal raphe nucleus; interactions between nociceptin/NOP system and serotonin

International audienceNociceptin/Orphanin FQ is the endogenous ligand of NOP receptor, formerly referred to as the Opioid Receptor-Like 1 receptor. We have previously shown that NOP receptors were located on serotonergic neurons in the rat dorsal raphe nucleus, suggesting possible direct interactions between nociceptin and serotonin in this region, which is a target for antidepressant action. In the present study, we investigated further the link between Selective Serotonin Reuptake Inhibitor (SSRI) antidepressant treatments and the nociceptin/NOP receptor system. Intraperitoneal administration of the SSRI citalopram induced an increase in NOP-receptor density, measured by autoradiographic [3H] nociceptin binding, in the rat dorsal raphe nucleus, from the first to the 21st day of treatment. This effect was also observed with other SSRIs (sertraline, fluoxetine), but not with two tricyclic antidepressants (imipramine, clomipramine) and was abolished by pre-treatment with para-chlorophenylalanine, an inhibitor of serotonin synthesis. Using microdialysis experiments, we demonstrated that NOP-receptor activation by infusion of nociceptin 10−6 M or 10−5 M increased the level of extracellular serotonin in the dorsal raphe nucleus. This effect was abolished by co-infusion of the NOP-receptor antagonist UFP 101. These results confirm the existence of reciprocal interactions between serotonin and nociceptin/NOP transmissions in the dorsal raphe nucleus

Experimental and clinical evidence of differential effects of magnesium sulfate on neuroprotection and angiogenesis in the fetal brain

International audienc

Time- and sex-dependent efficacy of magnesium sulfate to prevent behavioral impairments and cerebral damage in a mouse model of cerebral palsy

International audienc

Magnesium Sulfate Prevents Neurochemical and Long-Term Behavioral Consequences of Neonatal Excitotoxic Lesions: Comparison Between Male and Female Mice

International audienc