Zachary N.M. Luyo , Abigail B. Lawrence , Theodore G. Stathopoulos , Darlene A. Mitrano
{"title":"小鼠蓝斑中含有α1肾上腺素能受体元件的定位和神经化学特性。","authors":"Zachary N.M. Luyo , Abigail B. Lawrence , Theodore G. Stathopoulos , Darlene A. Mitrano","doi":"10.1016/j.jchemneu.2023.102343","DOIUrl":null,"url":null,"abstract":"<div><p><span>The locus coeruleus<span> (LC) is the major source for norepinephrine<span> (NE) in the brain and projects to areas involved in learning and memory, reward, arousal, attention, and autonomic functions related to stress. There are three types of adrenergic receptors<span> that respond to NE: alpha1-, alpha2-, and beta-adrenergic receptors. Previous behavioral studies have shown the alpha1-adrenergic receptor (α1AR) to be present in the LC, however, with conflicting results. For example, it was shown that α1ARs in the LC are involved in some of the motivational effects of stimulation of the medial forebrain bundle<span><span>, which was reduced by α1AR antagonist terazosin. Another study showed that during novelty-induced behavioral activation, the α1AR antagonist </span>prazosin reduced c-fos expression in brain regions known to contain motoric α1ARs, except for the LC, where c-fos expression was enhanced. Despite new research delineating more specific connectivity of the neurons in the LC, and some roles of the adrenergic receptors, the α1ARs have not been localized at the subcellular level. Therefore, in order to gain a greater understanding of the aforementioned studies, we used </span></span></span></span></span>immunohistochemistry<span> at the electron microscopic (EM) level to determine which neuronal or glial elements in the LC express the α1AR. We hypothesized, based on previous work in the ventral periaqueductal gray<span> area, that the α1AR would be found mainly presynaptically in axon terminals<span><span>, and possibly in glial elements. Single labeling immunohistochemistry at the EM revealed that about 40% of labeled elements that contained the α1AR were glial elements, while approximately 50% of the labeled neuronal elements were axon terminals or small unmyelinated axons in the LC. Double labeling immunohistochemistry found the α1AR expressed in GFAP-labeled astrocytes, in both GABAergic and glutamatergic axon terminals, and in a portion of the α1AR dendrites, colocalized with </span>tyrosine hydroxylase (TH, a marker for noradrenergic neurons). This study sheds light on the neuroanatomical framework underlying the effects of NE and pharmaceuticals acting directly or indirectly on α1ARs in the LC.</span></span></span></p></div>","PeriodicalId":15324,"journal":{"name":"Journal of chemical neuroanatomy","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2023-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Localization and neurochemical identity of alpha1-adrenergic receptor-containing elements in the mouse locus coeruleus\",\"authors\":\"Zachary N.M. Luyo , Abigail B. Lawrence , Theodore G. Stathopoulos , Darlene A. Mitrano\",\"doi\":\"10.1016/j.jchemneu.2023.102343\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p><span>The locus coeruleus<span> (LC) is the major source for norepinephrine<span> (NE) in the brain and projects to areas involved in learning and memory, reward, arousal, attention, and autonomic functions related to stress. There are three types of adrenergic receptors<span> that respond to NE: alpha1-, alpha2-, and beta-adrenergic receptors. Previous behavioral studies have shown the alpha1-adrenergic receptor (α1AR) to be present in the LC, however, with conflicting results. For example, it was shown that α1ARs in the LC are involved in some of the motivational effects of stimulation of the medial forebrain bundle<span><span>, which was reduced by α1AR antagonist terazosin. Another study showed that during novelty-induced behavioral activation, the α1AR antagonist </span>prazosin reduced c-fos expression in brain regions known to contain motoric α1ARs, except for the LC, where c-fos expression was enhanced. Despite new research delineating more specific connectivity of the neurons in the LC, and some roles of the adrenergic receptors, the α1ARs have not been localized at the subcellular level. Therefore, in order to gain a greater understanding of the aforementioned studies, we used </span></span></span></span></span>immunohistochemistry<span> at the electron microscopic (EM) level to determine which neuronal or glial elements in the LC express the α1AR. We hypothesized, based on previous work in the ventral periaqueductal gray<span> area, that the α1AR would be found mainly presynaptically in axon terminals<span><span>, and possibly in glial elements. Single labeling immunohistochemistry at the EM revealed that about 40% of labeled elements that contained the α1AR were glial elements, while approximately 50% of the labeled neuronal elements were axon terminals or small unmyelinated axons in the LC. Double labeling immunohistochemistry found the α1AR expressed in GFAP-labeled astrocytes, in both GABAergic and glutamatergic axon terminals, and in a portion of the α1AR dendrites, colocalized with </span>tyrosine hydroxylase (TH, a marker for noradrenergic neurons). This study sheds light on the neuroanatomical framework underlying the effects of NE and pharmaceuticals acting directly or indirectly on α1ARs in the LC.</span></span></span></p></div>\",\"PeriodicalId\":15324,\"journal\":{\"name\":\"Journal of chemical neuroanatomy\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.7000,\"publicationDate\":\"2023-09-28\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of chemical neuroanatomy\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0891061823001138\",\"RegionNum\":4,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"BIOCHEMISTRY & MOLECULAR BIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of chemical neuroanatomy","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0891061823001138","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
Localization and neurochemical identity of alpha1-adrenergic receptor-containing elements in the mouse locus coeruleus
The locus coeruleus (LC) is the major source for norepinephrine (NE) in the brain and projects to areas involved in learning and memory, reward, arousal, attention, and autonomic functions related to stress. There are three types of adrenergic receptors that respond to NE: alpha1-, alpha2-, and beta-adrenergic receptors. Previous behavioral studies have shown the alpha1-adrenergic receptor (α1AR) to be present in the LC, however, with conflicting results. For example, it was shown that α1ARs in the LC are involved in some of the motivational effects of stimulation of the medial forebrain bundle, which was reduced by α1AR antagonist terazosin. Another study showed that during novelty-induced behavioral activation, the α1AR antagonist prazosin reduced c-fos expression in brain regions known to contain motoric α1ARs, except for the LC, where c-fos expression was enhanced. Despite new research delineating more specific connectivity of the neurons in the LC, and some roles of the adrenergic receptors, the α1ARs have not been localized at the subcellular level. Therefore, in order to gain a greater understanding of the aforementioned studies, we used immunohistochemistry at the electron microscopic (EM) level to determine which neuronal or glial elements in the LC express the α1AR. We hypothesized, based on previous work in the ventral periaqueductal gray area, that the α1AR would be found mainly presynaptically in axon terminals, and possibly in glial elements. Single labeling immunohistochemistry at the EM revealed that about 40% of labeled elements that contained the α1AR were glial elements, while approximately 50% of the labeled neuronal elements were axon terminals or small unmyelinated axons in the LC. Double labeling immunohistochemistry found the α1AR expressed in GFAP-labeled astrocytes, in both GABAergic and glutamatergic axon terminals, and in a portion of the α1AR dendrites, colocalized with tyrosine hydroxylase (TH, a marker for noradrenergic neurons). This study sheds light on the neuroanatomical framework underlying the effects of NE and pharmaceuticals acting directly or indirectly on α1ARs in the LC.
期刊介绍:
The Journal of Chemical Neuroanatomy publishes scientific reports relating the functional and biochemical aspects of the nervous system with its microanatomical organization. The scope of the journal concentrates on reports which combine microanatomical, biochemical, pharmacological and behavioural approaches.
Papers should offer original data correlating the morphology of the nervous system (the brain and spinal cord in particular) with its biochemistry. The Journal of Chemical Neuroanatomy is particularly interested in publishing important studies performed with up-to-date methodology utilizing sensitive chemical microassays, hybridoma technology, immunocytochemistry, in situ hybridization and receptor radioautography, to name a few examples.
The Journal of Chemical Neuroanatomy is the natural vehicle for integrated studies utilizing these approaches. The articles will be selected by the editorial board and invited reviewers on the basis of their excellence and potential contribution to this field of neurosciences. Both in vivo and in vitro integrated studies in chemical neuroanatomy are appropriate subjects of interest to the journal. These studies should relate only to vertebrate species with particular emphasis on the mammalian and primate nervous systems.