Ovarian steroid hormones modulate circadian rhythms of neuroendocrine dopaminergic neuronal activity

Sellix, Michael T.; Egli, Marcel; Henderson, Ross P.; Freeman, Marc E.

doi:10.1016/j.brainres.2004.01.049

Cited by 16 publications

(13 citation statements)

References 67 publications

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“…Therefore, the rhythm of PER2 expression, but not PER1 expression, within THDA neurons corresponds to the rhythm of DA turnover observed for these neurons under a standard light-dark cycle. These data are surprising, given our previous report that THDA neurons exhibit clear diurnal rhythms with significant peaks near CT6 and CT12 (57,58). It remains to be seen whether PER1 and PER2 have redundant roles in the regulation of molecular feedback loops of circadian clock genes and/or DA synthetic enzyme expression in NDNs.…”

Section: Discussionmentioning

confidence: 75%

“…In addition, PER2 expression displayed a diurnal rhythm of expression with significant peaks at CT6 and CT12. We have previously reported a diurnal rhythm of DA turnover within TIDA neurons with a biphasic pattern, defined by peaks at CT6 and CT12 (57,58). Thus PER2 expression, but not PER1 expression, peaked in parallel with the time of peak DA turnover within these neurons.…”

Section: Discussionmentioning

confidence: 78%

“…Therefore, we observed a significant diurnal rhythm of PER1-IR within TIDA neurons. We have previously determined that TIDA neurons display a diurnal rhythm of DA release with a significant acrophase between CT0 and CT6 (57,58). Analysis of PER1-IR within the RARN of the hypothalamus did not reveal a significant effect of CT (F ϭ 0.52, P Ͼ 0.05, Fig.…”

Section: Diurnal Rhythms Of Per1-ir In Tida and Phda Neurons But Notmentioning

confidence: 85%

“…CT12 was used as a reference time for tissue collection under a standard 12:12-h light-dark cycle. The use of the CT scale allowed us to make direct comparisons between data collected in the current experiments and analyses of DA turnover performed under constant conditions in previously published reports (57,58). Double-plotted actograms of drinking activity (12-h moving average of drinking activity around a central peak of activity) were produced with Circadia software (version 2.1.16; Behavioral Cybernetics, Tallahassee, FL).…”

Section: Bilateral Ovariectomy and Analysis Of Drinking Rhythmsmentioning

confidence: 99%

“…We have observed diurnal rhythms of DA turnover in the nerve terminals of TIDA, THDA, and PHDA neurons in the ovariectomized (OVX) rat (57,58). Whereas both TIDA and PHDA neurons display circadian rhythms of DA release, THDA neurons failed to exhibit a free-running rhythm.…”

mentioning

confidence: 99%

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Anatomical and functional characterization of clock gene expression in neuroendocrine dopaminergic neurons

Sellix

Egli²,

Poletini³

et al. 2006

American Journal of Physiology-Regulatory, Integrative and Comp

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Oscillations of gene expression and physiological activity in suprachiasmatic nucleus (SCN) neurons result from autoregulatory feedback loops of circadian clock gene transcription factors. In the present experiment, we have determined the pattern of PERIOD1 (PER1), PERIOD2 (PER2), and CLOCK expression within neuroendocrine dopaminergic (DAergic) neurons (NDNs) of ovariectomized (OVX) rats. We have also determined the effects of per1, per2, and clock mRNA knockdown in the SCN with antisense deoxyoligonucleotides (AS-ODN) on DA release from NDNs. Diurnal rhythms of PER1 and PER2 expression in tuberoinfundibular DAergic (TIDA) and periventricular hypophyseal DAergic (PHDA) neurons, peaked at circadian time (CT)18 and CT12, respectively. Rhythms of PER1 expression in tuberhypophyseal neuroendocrine DAergic (THDA) neurons were undetectable. Rhythms of PER2 expression were found in all three populations of NDNs, with greater levels of PER2 expression between CT6 and CT12. AS-ODN injections differentially affected DA turnover in the axon terminals of the median eminence (ME), neural lobe (NL) and intermediate lobe (IL) of the pituitary gland, resulting in a significant decrease in DA release in the early subjective night in the ME (TIDA), a significant increase in DA release at the beginning of the day in the IL (PHDA), and no effect in the NL (THDA). AS-ODN-treatment induced a rhythm of DA concentration in the anterior lobe, with greater DA levels in the middle of the day. These data suggest that clock gene expression, particularly PER1 and PER2, within NDNs may act to modulate diurnal rhythms of DA release from NDNs in the OVX rat.prolactin; dopamine; suprachiasmatic nucleus; hypothalamus DOPAMINE (DA) of hypothalamic origin exerts tonic inhibitory control over prolactin (PRL) secretion (for review see Ref. 17). DA is released directly into hypothalamo-hypophyseal portal blood from three populations of neuroendocrine DAergic neurons (NDNs) (5, 17). These subpopulations include the tuberoinfundibular DAergic (TIDA) and tuberohypophyseal neuroendocrine DAergic (THDA,A12) neurons with cell bodies in the arcuate nucleus (ARN) and periventricular hypophyseal DAergic (PHDA,A14) neurons with cell bodies in the periventricular region (5, 17). THDA and PHDA axons traverse the pituitary stalk and terminate on fenestrated short portal vessels within the neural (NL) and intermediate (IL) lobes of the pituitary gland (21). TIDA axons terminate on fenestrated capillary beds within the external zone of the median eminence (ME) that drain into long portal vessels, transporting DA to the anterior lobe (AL) of the pituitary gland (8, 10). TIDA neurons are well established as the primary PRL inhibitory neurons, although growing importance has been assigned to both THDA and PHDA neurons in the regulation of PRL secretion (13, 21, 43, 52, 61).We have observed diurnal rhythms of DA turnover in the nerve terminals of TIDA, THDA, and PHDA neurons in the ovariectomized (OVX) rat (57, 58). Whereas both TIDA and PHDA neurons display circadian ...

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Section: Discussionmentioning

confidence: 75%

Section: Discussionmentioning

confidence: 78%

Section: Diurnal Rhythms Of Per1-ir In Tida and Phda Neurons But Notmentioning

confidence: 85%

Section: Bilateral Ovariectomy and Analysis Of Drinking Rhythmsmentioning

confidence: 99%

mentioning

confidence: 99%

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Anatomical and functional characterization of clock gene expression in neuroendocrine dopaminergic neurons

Sellix

Egli²,

Poletini³

et al. 2006

American Journal of Physiology-Regulatory, Integrative and Comp

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The stability of the transcriptome during the estrous cycle in four regions of the mouse brain

DiCarlo

Vied

Nowakowski

2017

J of Comparative Neurology

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We analyzed the transcriptome of the C57BL/6J mouse hypothalamus, hippocampus, neocortex, and cerebellum to determine estrous cycle-specific changes in these four brain regions. We found almost 16,000 genes are present in one or more of the brain areas but only 210 genes, ∼1.3%, are significantly changed as a result of the estrous cycle. The hippocampus has the largest number of differentially expressed genes (DEGs) (82), followed by the neocortex (76), hypothalamus (63), and cerebellum (26). Most of these DEGs (186/210) are differentially expressed in only one of the four brain regions. A key finding is the unique expression pattern of growth hormone (Gh) and prolactin (Prl). Gh and Prl are the only DEGs to be expressed during only one stage of the estrous cycle (metestrus). To gain insight into the function of the DEGs, we examined gene ontology and phenotype enrichment and found significant enrichment for genes associated with myelination, hormone stimulus, and abnormal hormone levels. Additionally, 61 of the 210 DEGs are known to change in response to estrogen in the brain. 50 of the 210 genes differentially expressed as a result of the estrous cycle are related to myelin and oligodendrocytes and 12 of the 63 DEGs in the hypothalamus are oligodendrocyte- and myelin-specific genes. This transcriptomic analysis reveals that gene expression in the female mouse brain is remarkably stable during the estrous cycle and demonstrates that the genes that do fluctuate are functionally related.

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Hypothalamic Control of Prolactin Secretion, and the Multiple Reproductive Functions of Prolactin

Grattan

Tissier²

2015

Knobil and Neill's Physiology of Reproduction

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Ovarian steroid hormones modulate circadian rhythms of neuroendocrine dopaminergic neuronal activity

Cited by 16 publications

References 67 publications

Anatomical and functional characterization of clock gene expression in neuroendocrine dopaminergic neurons

Anatomical and functional characterization of clock gene expression in neuroendocrine dopaminergic neurons

The stability of the transcriptome during the estrous cycle in four regions of the mouse brain

Hypothalamic Control of Prolactin Secretion, and the Multiple Reproductive Functions of Prolactin

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