Enlightened: addressing circadian and seasonal changes in photoperiod in animal models of bipolar disorder
Abstract Bipolar disorders (BDs) exhibit high heritability and symptoms typically first occur during late adolescence or early adulthood. Affected individuals may experience alternating bouts of mania/hypomania and depression, with euthymic periods of varying lengths interspersed between these extre...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Nature Publishing Group
2021-07-01
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| Series: | Translational Psychiatry |
| Online Access: | https://doi.org/10.1038/s41398-021-01494-5 |
| _version_ | 1818738136273911808 |
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| author | Richard McCarty Travis Josephs Oleg Kovtun Sandra J. Rosenthal |
| author_facet | Richard McCarty Travis Josephs Oleg Kovtun Sandra J. Rosenthal |
| author_sort | Richard McCarty |
| collection | DOAJ |
| description | Abstract Bipolar disorders (BDs) exhibit high heritability and symptoms typically first occur during late adolescence or early adulthood. Affected individuals may experience alternating bouts of mania/hypomania and depression, with euthymic periods of varying lengths interspersed between these extremes of mood. Clinical research studies have consistently demonstrated that BD patients have disturbances in circadian and seasonal rhythms, even when they are free of symptoms. In addition, some BD patients display seasonal patterns in the occurrence of manic/hypomanic and depressive episodes as well as the time of year when symptoms initially occur. Finally, the age of onset of BD symptoms is strongly influenced by the distance one lives from the equator. With few exceptions, animal models useful in the study of BD have not capitalized on these clinical findings regarding seasonal patterns in BD to explore molecular mechanisms associated with the expression of mania- and depression-like behaviors in laboratory animals. In particular, animal models would be especially useful in studying how rates of change in photoperiod that occur during early spring and fall interact with risk genes to increase the occurrence of mania- and depression-like phenotypes, respectively. Another unanswered question relates to the ways in which seasonally relevant changes in photoperiod affect responses to acute and chronic stressors in animal models. Going forward, we suggest ways in which translational research with animal models of BD could be strengthened through carefully controlled manipulations of photoperiod to enhance our understanding of mechanisms underlying seasonal patterns of BD symptoms in humans. In addition, we emphasize the value of incorporating diurnal rodent species as more appropriate animal models to study the effects of seasonal changes in light on symptoms of depression and mania that are characteristic of BD in humans. |
| first_indexed | 2024-12-18T01:04:08Z |
| format | Article |
| id | doaj.art-83908560591142559b84186265412c35 |
| institution | Directory Open Access Journal |
| issn | 2158-3188 |
| language | English |
| last_indexed | 2024-12-18T01:04:08Z |
| publishDate | 2021-07-01 |
| publisher | Nature Publishing Group |
| record_format | Article |
| series | Translational Psychiatry |
| spelling | doaj.art-83908560591142559b84186265412c352022-12-21T21:26:17ZengNature Publishing GroupTranslational Psychiatry2158-31882021-07-0111111210.1038/s41398-021-01494-5Enlightened: addressing circadian and seasonal changes in photoperiod in animal models of bipolar disorderRichard McCarty0Travis Josephs1Oleg Kovtun2Sandra J. Rosenthal3Department of Psychology, Vanderbilt UniversityNeuroscience Program, Vanderbilt UniversityDepartment of Chemistry, Vanderbilt UniversityDepartment of Chemistry, Vanderbilt UniversityAbstract Bipolar disorders (BDs) exhibit high heritability and symptoms typically first occur during late adolescence or early adulthood. Affected individuals may experience alternating bouts of mania/hypomania and depression, with euthymic periods of varying lengths interspersed between these extremes of mood. Clinical research studies have consistently demonstrated that BD patients have disturbances in circadian and seasonal rhythms, even when they are free of symptoms. In addition, some BD patients display seasonal patterns in the occurrence of manic/hypomanic and depressive episodes as well as the time of year when symptoms initially occur. Finally, the age of onset of BD symptoms is strongly influenced by the distance one lives from the equator. With few exceptions, animal models useful in the study of BD have not capitalized on these clinical findings regarding seasonal patterns in BD to explore molecular mechanisms associated with the expression of mania- and depression-like behaviors in laboratory animals. In particular, animal models would be especially useful in studying how rates of change in photoperiod that occur during early spring and fall interact with risk genes to increase the occurrence of mania- and depression-like phenotypes, respectively. Another unanswered question relates to the ways in which seasonally relevant changes in photoperiod affect responses to acute and chronic stressors in animal models. Going forward, we suggest ways in which translational research with animal models of BD could be strengthened through carefully controlled manipulations of photoperiod to enhance our understanding of mechanisms underlying seasonal patterns of BD symptoms in humans. In addition, we emphasize the value of incorporating diurnal rodent species as more appropriate animal models to study the effects of seasonal changes in light on symptoms of depression and mania that are characteristic of BD in humans.https://doi.org/10.1038/s41398-021-01494-5 |
| spellingShingle | Richard McCarty Travis Josephs Oleg Kovtun Sandra J. Rosenthal Enlightened: addressing circadian and seasonal changes in photoperiod in animal models of bipolar disorder Translational Psychiatry |
| title | Enlightened: addressing circadian and seasonal changes in photoperiod in animal models of bipolar disorder |
| title_full | Enlightened: addressing circadian and seasonal changes in photoperiod in animal models of bipolar disorder |
| title_fullStr | Enlightened: addressing circadian and seasonal changes in photoperiod in animal models of bipolar disorder |
| title_full_unstemmed | Enlightened: addressing circadian and seasonal changes in photoperiod in animal models of bipolar disorder |
| title_short | Enlightened: addressing circadian and seasonal changes in photoperiod in animal models of bipolar disorder |
| title_sort | enlightened addressing circadian and seasonal changes in photoperiod in animal models of bipolar disorder |
| url | https://doi.org/10.1038/s41398-021-01494-5 |
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