Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mu opioid receptor ligands such as morphine and met-enkephalin are known to modulate normal brain development by perturbing gliogenesis and inhibiting neuronal proliferation. Surprisingly, the distribution of the mu opioid receptor (MOR) in the embryonic brain, especially in proliferative regions, is poorly defined and subject to conflicting reports. Using an immunohistochemical approach, we found that MOR protein was expressed in the neuroepithelia of the lateral ventricles, third ventricle, and aqueduct within the late embryonic (E15.5 and E18.5) mouse brain. In contrast to the ventricular neuroepithelia, the proliferative external granule layer of the embryonic cerebellum did not express MOR protein, although the Purkinje cell layer did. Within the ventricular neuroepithelium, GLAST-positive radial glia that incorporate BrdU expressed MOR, while migrating neuroblasts (doublecortin-positive) do not. BrdU labeling of proliferating cells showed an anterior to posterior gradient of proliferation (P<0.05), while an opposing posterior to anterior gradient of MOR expression (P<0.05) was found. The localization of MOR immunoreactivity within the embryonic ventricular neuroepithelia is consistent with a role for opioids in modulating neurogenesis.
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PMID:Mu opioid receptors are expressed on radial glia but not migrating neuroblasts in the late embryonic mouse brain. 1788 89

Altered social behaviours are a hallmark of several psychiatric and developmental disorders. Clinical and preclinical data have demonstrated that prenatal exposure to valproic acid (VPA), an anti-epileptic and mood stabiliser, is associated with impaired social responses, and thus provides a useful model for the evaluation of neurobiological mechanisms underlying altered social behaviours. The opioid system is widely recognised to regulate and modulate social behaviours, however few studies have examined if the endogenous opioid system is altered in animal models of social impairment. The present study examined social behavioural responses of adolescent and adult male rats prenatally exposed to VPA, and the expression of mRNA encoding opioid receptors and pre-pro-peptides in discrete brain regions. Adolescent and adult rats prenatally exposed to VPA spent less time engaging in social behaviours in the direct social interaction test and exhibited reduced sociability and social novelty preference in the 3-chamber sociability test, compared to saline-treated counterparts. The VPA-exposed adolescent rats exhibited significantly reduced kappa opioid receptor (oprk1) and pre-pro-dynorphin (pdyn) mRNA expression in the cerebral cortex, and reduced oprk1 and nociceptin/orphanin FQ (oprl1) mRNA expression in the hypothalamus. Adult rats prenatally exposed to VPA exhibited decreased mRNA expression of oprk1 and pdyn in hypothalamus, reduced pro-opiomelanocortin(pomc) in the striatum and an increase in delta opioid receptor (oprd1) mRNA in the amygdaloid cortex, when compared to saline-treated counterparts. Mu opioid receptor (oprm1) mRNA expression did not differ between saline and VPA-exposed rats in any region examined. The data demonstrate that impaired social behaviours in adolescent and adult rats prenatally exposed to VPA is accompanied by altered mRNA expression of opioid receptors and pre-pro-peptides in a region specific manner. In particular, both adolescent and adult VPA-exposed rats exhibit reduced oprk1-pdyn mRNA expression in several brain regions, which are associated with deficits in social behavioural responding in the model.
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PMID:Prenatal exposure to valproic acid reduces social responses and alters mRNA levels of opioid receptor and pre-pro-peptide in discrete brain regions of adolescent and adult male rats. 3197 76