Neurons with Mu Opioid Receptors Interact Indirectly with Enkephalin-Containing Neurons in the Rat Dentate Gyrus

Drake, Carrie T.; Chang, P. C.; Harris, Jonathan; Milner, Teresa A.

doi:10.1006/exnr.2002.7948

Cited by 20 publications

(17 citation statements)

References 39 publications

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“…In a double-labeling study, there was colocalization of these two receptors with GFAP, a marker of glial astrocytes, in these small cells. The results indicate that deltaand mu-opioid receptors are present in the glia of the bovine pineal gland, in agreement with previous reports [Eriksson et al, 1990[Eriksson et al, , 1991Ruzicka et al, 1995;Cheng et al, 1997;Drake et al, 2002]. A possible role of endogenous opioids in the regulation of both neuronal and glia proliferation and growth has been suggested [Stiene-Martin et al, 2001].…”

Section: Opioid Receptors In Glial Cellssupporting

confidence: 81%

Immunocytochemical Characterization of Delta-Opioid and Mu-Opioid Receptor Protein in the Bovine Pineal Gland

Phansuwan‐Pujito

Ebadi²,

Govitrapong³

2006

Cells Tissues Organs

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Opioidergic innervation has been identified in the mammalian pineal gland. Recently, opioid receptors in bovine pineal glands have been characterized; the activation of these receptors leads to the stimulation of melatonin synthesis. In this study, the precise localization of opioid receptors in bovine pineal glands was determined by an immunohistochemical technique using antibodies raised against delta-opioid and mu-opioid receptors. Immunoreactivity of these two receptors was present at a moderate level in pinealocytes. A double-labeling study has shown that delta-opioid receptors are localized predominantly with mu-opioid receptors in the same pinealocytes. These immunopositive pinealocytes are often located in a group; however, some of them are dispersed individually. In addition, both types of receptors were found in glial cells and processes. A small number of delta-receptor-immunoreactive nerve fibers were observed in the perivascular space and intraparenchyma of the pineal gland. Mu-opioid receptor immunoreactivity was found in a number of nerve fibers throughout the gland, and in terminal-like dots on pinealocytes. There was immunocolocalization between delta-opioid receptors or mu-opioid receptors and leu-enkephalin in some nerve fibers. The results of this study indicate that the modulatory effect of the opioid system on melatonin secretion in pineal glands might act via opioid receptors on pinealocytes, whereas receptors located on nerve fibers might modulate the release of opioid peptides.

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Section: Opioid Receptors In Glial Cellssupporting

confidence: 81%

Immunocytochemical Characterization of Delta-Opioid and Mu-Opioid Receptor Protein in the Bovine Pineal Gland

Phansuwan‐Pujito

Ebadi²,

Govitrapong³

2006

Cells Tissues Organs

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“…It is also interesting to consider whether newly born SGZ cells express receptors through which opiates and psychostimulants can act relatively directly. Indirect evidence suggests that l-opiate and dopamine receptors may be expressed on SGZ precursors (Verney et al, 1985;Milner and Bacon, 1989;Gasbarri et al, 1991Gasbarri et al, , 1994Goldsmith and Joyce, 1994;Drake et al, 2002;Hoglinger et al, 2004;Harburg et al, 2005). However, as acute opiate or psychostimulant does not alter SGZ proliferation in the rat Yamaguchi et al, 2004Yamaguchi et al, , 2005, future research may focus not on the presence of these receptors but rather on chronic drug-induced neuroadaptations in the intracellular cascades linked to these receptors (Koob and Nestler, 1997;White and Kalivas, 1998;Nestler, 2001a).…”

Section: Direct Action On Progenitor Cellsmentioning

confidence: 95%

Opiates, psychostimulants, and adult hippocampal neurogenesis: Insights for addiction and stem cell biology

2006

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Once thought to produce global, nonspecific brain injury, drugs of abuse are now known to produce selective neuro-adaptations in particular brain regions. These neuro-adaptations are being closely examined for clues to the development, maintenance, and treatment of addiction. The hippocampus is an area of particular interest, as it is central to many aspects of the addictive process, including relapse to drug taking. A recently appreciated hippocampal neuro-adaptation produced by drugs as diverse as opiates and psychostimulants is decreased neurogenesis in the sub-granular zone (SGZ). While the role of adult-generated neurons is not clear, their functional integration into hippocampal circuitry raises the possibility that decreased adult SGZ neurogenesis may alter hippocampal function in such a way as to maintain addictive behavior or contribute to relapse. Here, we review the impact of opiates and psychostimulants on the different stages of cell development in the adult brain, as well as the different stages of the addictive process. We discuss how examination of drug-induced alterations of adult neurogenesis advances our understanding of the complex mechanisms by which opiates and psychostimulants affect brain function while also opening avenues for novel ways of assessing the functional role of adult-generated neurons. In addition, we highlight key discrepancies in the field and underscore the necessity to move "beyond BrdU"--beyond merely counting new hippocampal cells labeled with the S phase marker bromodeoxyuridine--so as to probe mechanistic questions about how drug-induced alterations in adult hippocampal neurogenesis occur and what the functional ramifications of alterations in neurogenesis are for addiction.

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“…To provide uniform labeling conditions in preparation for making quantitative comparisons (Auchus and Pickel, 1992), sections from control and experimental brains were first punched to allow identification and pooled into single containers prior to processing to immunoperoxidase label LENK. For this purpose, a mouse monoclonal antibody to leu 5 -enkephalin from Sera Labs (Crawley Down, UK), which has been extensively characterized and used previously to immunolabel the MF system (Commons and Milner, 1995; Drake et al, 2002; Milner et al, 1989; Torres-Reveron et al, 2008; Van Kempen et al, 2013) was employed. The immunolabeling procedure first involved incubating pooled tissue in a 1% sodium borohydride solution in PB for 30 min, extensive rinsing, followed by incubation in a 0.5% bovine serum albumin (BSA) solution for 30 min, and further rinsing.…”

Section: Methodsmentioning

confidence: 99%

Hippocampal mossy fiber leu-enkephalin immunoreactivity in female rats is significantly altered following both acute and chronic stress

Pierce

Kelter

McEwen

et al. 2014

Journal of Chemical Neuroanatomy

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Research indicates that responses to stress are sexually dimorphic, particularly in regard to learning and memory processes: while males display impaired cognitive performance and hippocampal CA3 pyramidal cell dendritic remodeling following chronic stress, females exhibit enhanced performance and no remodeling. Leu-enkephalin, an endogenous opioid peptide found in the hippocampal mossy fiber pathway, plays a critical role in mediating synaptic plasticity at the mossy fiber-CA3 pyramidal cell synapse. Estrogen is known to influence the expression of leu-enkephalin in the mossy fibers of females, with leu-enkephalin levels being highest at proestrus and estrus, when estrogen levels are elevated. Since stress is also known to alter the expression of leu-enkephalin in various brain regions, this study was designed to determine whether acute or chronic stress had an effect on mossy fiber leu-enkephalin levels in females or males, through the application of correlated quantitative light and electron microscopic immunocytochemistry. Both acute and chronic stress eliminated the estrogen-dependence of leu-enkephalin levels across the estrous cycle in females, but had no effect on male levels. However, following acute stress leu-enkephalin levels in females were consistently lowered to values comparable to the lowest control values, while following chronic stress they were consistently elevated to values comparable to the highest control values. Ultrastructural changes in leu-enkephalin labeled dense core vesicles paralleled light microscopic observations, with acute stress inducing a decrease in leu-enkephalin labeled dense core vesicles, and chronic stress inducing an increase in leu-enkephalin labeled dense-core vesicles in females. These findings suggest that alterations in leu-enkephalin levels following stress could play an important role in the sex-specific responses that females display in learning processes, including those important in addiction.

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Neurons with Mu Opioid Receptors Interact Indirectly with Enkephalin-Containing Neurons in the Rat Dentate Gyrus

Cited by 20 publications

References 39 publications

Immunocytochemical Characterization of Delta-Opioid and Mu-Opioid Receptor Protein in the Bovine Pineal Gland

Immunocytochemical Characterization of Delta-Opioid and Mu-Opioid Receptor Protein in the Bovine Pineal Gland

Opiates, psychostimulants, and adult hippocampal neurogenesis: Insights for addiction and stem cell biology

Hippocampal mossy fiber leu-enkephalin immunoreactivity in female rats is significantly altered following both acute and chronic stress

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