scholarly journals Colocalization of MOR1 and GAD67 in Mouse Nucleus Accumbens

2019 ◽  
Author(s):  
Chad Hinkle ◽  
Eduard Dedkov ◽  
Russell Buono ◽  
Thomas Ferraro
Keyword(s):  
Plasma Membrane ◽  
Nucleus Accumbens ◽  
Nuclear Membrane ◽  
Anterior Commissure ◽  
Endogenous Opioids ◽  
Small Subset ◽  
Neuronal Nucleus ◽  
Neurotransmitter Systems ◽  
Gabaergic Neurotransmission ◽  
Reward Pathway

ABSTRACTCurrent understanding of the rewarding and addictive effects of opioids involves mu-opioid receptor (MOR) binding within the nucleus accumbens (NAcc), a region of the ventral striatum. GABAergic neurotransmission in the NAcc potentiates the rewarding response to opioids, and in fact, drugs that stimulate GABAergic activity are also addictive, a phenomenon mediated in part by endogenous opioids. However, the neuroanatomical relationship between opioid and GABA systems is still unclear, and further study of the interaction between these neurotransmitter systems in the reward pathway is warranted. We report evidence supporting the direct interaction between GABAergic and opioidergic neurotransmitter systems within the mouse NAcc. Male and female FVB/NJ mice (12-16 months of age) were euthanized via carbon dioxide inhalation and brains processed for histology and immunohistochemistry (IHC). Coronal cryosections (10-12 um in thickness) were taken through the NAcc at the level of the anterior commissure. A mouse monoclonal antibody against GAD67, an enzyme catalyzing GABA production, was used in conjunction with an anti-mouse rhodamine red-X-labeled secondary antibody to identify GABAergic neurons in the NAcc. Alternating sections were stained for MOR using a fluorescein isothiocyanate (FITC)-conjugated rabbit polyclonal anti-MOR1 antibody. DAPI (4′,6-diamidino-2-phenylindole) was used to counterstain the nuclei. As expected, fluorescence microscopy results show that GAD67 staining is localized predominately in the neuronal cytoplasm, with approximately 40% of the population staining. The MOR1-FITC stain showed localization within the cytoplasm and plasma membrane as expected, however, there was also significant staining in the nuclear membrane and neuronal nucleus. MOR1-FITC was present in approximately 35% of the neuronal population. In separate experiments, we used double-immunostaining to study the co-expression of MOR1 and GAD67 within the same NAcc neurons. A similar localization pattern was detected with a small subset, approximately 2%, of neurons expressing both labels. There are few published reports of GAD67 and MOR1 co-expression within neurons of the NAcc. Previous studies of MOR expression show the receptor to be localized to the plasma membrane and, to a smaller degree, intracellularly. Here we found the MOR1 staining to be predominantly in the nucleus and nuclear membrane, with minimal expression on the plasma membrane. Further studies are in progress to validate the nuclear expression of MOR in GABAergic NAcc neurons. Results of the study suggest that a subset of mouse NAcc neurons express both MOR1 and GAD67, providing a direct intracellular link between opioid and GABAergic systems in the reward pathway. Preliminary intranuclear localization of MOR suggests a novel signaling pathway that may be important in fully elucidating neurobiological mechanisms underlying behaviors related to reward and addiction.

scholarly journals The fine structure produced in cells by primary fixatives 2. Potassium dichromate

1965 ◽  
Vol s3-106 (73) ◽  
pp. 15-21
Author(s):  
JOHN R. BAKER
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Fine Structure ◽  
Golgi Apparatus ◽  
Nuclear Membrane ◽  
Osmium Tetroxide ◽  
Potassium Dichromate ◽  
Potassium Dichromate Solution ◽  
Zymogen Granules ◽  
Mouse Pancreas

The exocrine cells of the mouse pancreas were fixed in potassium dichromate solution, embedded in araldite or other suitable medium, and examined by electron microscopy. Almost every part of these cells is seriously distorted or destroyed by this fixative. The ergastoplasm is generally unrecognizable, the mitochondria and zymogen granules are seldom visible, and no sign of the plasma membrane, microvilli, or Golgi apparatus is seen. The contents of the nucleus are profoundly rearranged. It is seen to contain a large, dark, irregularly shaped, finely granular object; the evidence suggests that this consists of coagulated histone. The sole constituent of the cell that is well fixed is the inner nuclear membrane. The destructive properties of potassium dichromate are much mitigated when it is mixed in suitable proportions with osmium tetroxide or formaldehyde.

Interaction between Endogenous Opioids and Dopamine within the Nucleus Accumbens

1992 ◽  
Vol 654 (1 The Neurobiol) ◽  
pp. 254-273 ◽  
Author(s):  
L. STINUS ◽  
M. CADOR ◽  
M. LE MOAL
Keyword(s):  
Nucleus Accumbens ◽  
Endogenous Opioids

scholarly journals Endosomal signaling of delta opioid receptors is an endogenous mechanism and therapeutic target for relief from inflammatory pain

2020 ◽  
Vol 117 (26) ◽  
pp. 15281-15292 ◽  
Author(s):  
Nestor N. Jimenez-Vargas ◽  
Jing Gong ◽  
Matthew J. Wisdom ◽  
Dane D. Jensen ◽  
Rocco Latorre ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Opioid Receptors ◽  
Therapeutic Target ◽  
Inflammatory Pain ◽  
Endogenous Opioids ◽  
Nanoparticle Delivery ◽  
Delta Opioid Receptors ◽  
Extracellular Signal ◽  
Early Endosomes ◽  
Endosomal Signaling

Whether G protein-coupled receptors signal from endosomes to control important pathophysiological processes and are therapeutic targets is uncertain. We report that opioids from the inflamed colon activate δ-opioid receptors (DOPr) in endosomes of nociceptors. Biopsy samples of inflamed colonic mucosa from patients and mice with colitis released opioids that activated DOPr on nociceptors to cause a sustained decrease in excitability. DOPr agonists inhibited mechanically sensitive colonic nociceptors. DOPr endocytosis and endosomal signaling by protein kinase C (PKC) and extracellular signal-regulated kinase (ERK) pathways mediated the sustained inhibitory actions of endogenous opioids and DOPr agonists. DOPr agonists stimulated the recruitment of Gαi/oand β-arrestin1/2 to endosomes. Analysis of compartmentalized signaling revealed a requirement of DOPr endocytosis for activation of PKC at the plasma membrane and in the cytosol and ERK in the nucleus. We explored a nanoparticle delivery strategy to evaluate whether endosomal DOPr might be a therapeutic target for pain. The DOPr agonist DADLE was coupled to a liposome shell for targeting DOPr-positive nociceptors and incorporated into a mesoporous silica core for release in the acidic and reducing endosomal environment. Nanoparticles activated DOPr at the plasma membrane, were preferentially endocytosed by DOPr-expressing cells, and were delivered to DOPr-positive early endosomes. Nanoparticles caused a long-lasting activation of DOPr in endosomes, which provided sustained inhibition of nociceptor excitability and relief from inflammatory pain. Conversely, nanoparticles containing a DOPr antagonist abolished the sustained inhibitory effects of DADLE. Thus, DOPr in endosomes is an endogenous mechanism and a therapeutic target for relief from chronic inflammatory pain.

scholarly journals Endogenous opioids in the nucleus accumbens promote approach to high-fat food in the absence of caloric need

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Kevin Caref ◽  
Saleem M Nicola
Keyword(s):  
Nucleus Accumbens ◽  
Receptor Antagonist ◽  
Neural Control ◽  
Neural Mechanism ◽  
Endogenous Opioids ◽  
Neuronal Firing ◽  
Palatable Food ◽  
Sugar Consumption ◽  
High Fat ◽  
The Brain

When relatively sated, people (and rodents) are still easily tempted to consume calorie-dense foods, particularly those containing fat and sugar. Consumption of such foods while calorically replete likely contributes to obesity. The nucleus accumbens (NAc) opioid system has long been viewed as a critical substrate for this behavior, mainly via contributions to the neural control of consumption and palatability. Here, we test the hypothesis that endogenous NAc opioids also promote appetitive approach to calorie-dense food in states of relatively high satiety. We simultaneously recorded NAc neuronal firing and infused a µ-opioid receptor antagonist into the NAc while rats performed a cued approach task in which appetitive and consummatory phases were well separated. The results reveal elements of a neural mechanism by which NAc opioids promote approach to high-fat food despite the lack of caloric need, demonstrating a potential means by which the brain is biased towards overconsumption of palatable food.

scholarly journals CHARACTERIZATION OF RAT LIVER SUBCELLULAR MEMBRANES

1974 ◽  
Vol 60 (2) ◽  
pp. 460-472 ◽  
Author(s):  
David H. DeHeer ◽  
Merle S. Olson ◽  
R. Neal Pinckard
Keyword(s):  
Plasma Membrane ◽  
Rat Liver ◽  
Nuclear Membrane ◽  
Membrane Fraction ◽  
Cross Reactivity ◽  
Selective Absorption ◽  
Mitochondrial Membranes ◽  
Subcellular Membrane ◽  
Hepatocellular Necrosis

The induction of acute hepatocellular necrosis in rats resulted in the production of complement fixing, IgM autoantibodies directed toward inner and outer mitochondrial membranes, microsomal membrane, lysosomal membrane, nuclear membrane, cytosol, but not to plasma membrane. Utilizing selective absorption procedures it was demonstrated that each subcellular membrane fraction possessed unique autoantigenic activity with little or no cross-reactivity between the various membrane fractions. It is proposed that the development of membrane-specific autoantibodies may provide an immunological marker useful in the differential characterization of various subcellular membranes.

The Nucleus Accumbens beyond the Anterior Commissure: Implications for Psychosurgery

2014 ◽  
Vol 92 (5) ◽  
pp. 291-299 ◽  
Author(s):  
Lia Lucas-Neto ◽  
Beatriz Mourato ◽  
Daniel Neto ◽  
Edson Oliveira ◽  
Hugo Martins ◽  
...  
Keyword(s):  
Nucleus Accumbens ◽  
Anterior Commissure

Ghrelin induces feeding in the mesolimbic reward pathway between the ventral tegmental area and the nucleus accumbens

Peptides ◽  
2005 ◽  
Vol 26 (11) ◽  
pp. 2274-2279 ◽  
Author(s):  
Amy M. Naleid ◽  
Martha K. Grace ◽  
David E. Cummings ◽  
Allen S. Levine
Keyword(s):  
Nucleus Accumbens ◽  
Ventral Tegmental Area ◽  
Reward Pathway ◽  
Ventral Tegmental

scholarly journals 5-lipoxygenase and 5-lipoxygenase-activating protein are localized in the nuclear envelope of activated human leukocytes.

1993 ◽  
Vol 178 (6) ◽  
pp. 1935-1946 ◽  
Author(s):  
J W Woods ◽  
J F Evans ◽  
D Ethier ◽  
S Scott ◽  
P J Vickers ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Plasma Membrane ◽  
Nuclear Envelope ◽  
Nuclear Membrane ◽  
Membrane Fraction ◽  
Subcellular Fractionation ◽  
Binding Activity ◽  
Resting Cells ◽  
Human Leukocytes ◽  
Ultrathin Frozen Sections

The intracellular distribution of the enzyme 5-lipoxygenase (5-LO) and 5-lipoxygenase-activating protein (FLAP) in resting and ionophore-activated human leukocytes has been determined using immuno-electronmicroscopic labeling of ultrathin frozen sections and subcellular fractionation techniques. 5-LO is a 78-kD protein that catalyzes the conversion of arachidonic acid to leukotrienes. FLAP is an 18-kD membrane bound protein that is essential for leukotriene synthesis in cells. In response to ionophore stimulation, 5-LO translocates from a soluble to a sedimentable fraction of cell homogenates. In activated leukocytes, both FLAP and 5-LO were localized in the lumen of the nuclear envelope. Neither protein could be detected in any other cell compartment or along the plasma membrane. In resting cells, the FLAP distribution was identical to that observed in activated cells. In addition, subcellular fractionation techniques showed > 83% of immunoblot-detectable FLAP protein and approximately 64% of the FLAP ligand binding activity was found in the nuclear membrane fraction. A fractionation control demonstrated that a plasma membrane marker, detected by a monoclonal antibody PMN13F6, was not detectable in the nuclear membrane fraction. In contrast to FLAP, 5-LO in resting cells could not be visualized along the nuclear envelope. Except for weak labeling of the euchromatin region of the nucleus, 5-LO could not be readily detected in any other cellular compartment. These results demonstrate that the nuclear envelope is the intracellular site at which 5-LO and FLAP act to metabolize arachidonic acid, and that ionophore activation of neutrophils and monocytes results in the translocation of 5-LO from a nonsedimentable location to the nuclear envelope.

scholarly journals The serotonin 5-HT2C receptor and the non-addictive nature of classic hallucinogens

2016 ◽  
Vol 31 (1) ◽  
pp. 127-143 ◽  
Author(s):  
Clinton E Canal ◽  
Kevin S Murnane
Keyword(s):  
Nucleus Accumbens ◽  
Inhibitory Activity ◽  
Comprehensive Analysis ◽  
Neuron Activity ◽  
Medium Spiny Neurons ◽  
Preclinical Studies ◽  
Spiny Neurons ◽  
Reward Pathway ◽  
Gabaergic Activity ◽  
Stimulation Of

Classic hallucinogens share pharmacology as serotonin 5-HT2A, 5-HT2B, and 5-HT2C receptor agonists. Unique among most other Schedule 1 drugs, they are generally non-addictive and can be effective tools in the treatment of addiction. Mechanisms underlying these attributes are largely unknown. However, many preclinical studies show that 5-HT2C agonists counteract the addictive effects of drugs from several classes, suggesting this pharmacological property of classic hallucinogens may be significant. Drawing from a comprehensive analysis of preclinical behavior, neuroanatomy, and neurochemistry studies, this review builds rationale for this hypothesis, and also proposes a testable, neurobiological framework. 5-HT2C agonists work, in part, by modulating dopamine neuron activity in the ventral tegmental area—nucleus accumbens (NAc) reward pathway. We argue that activation of 5-HT2C receptors on NAc shell, GABAergic, medium spiny neurons inhibits potassium Kv1.x channels, thereby enhancing inhibitory activity via intrinsic mechanisms. Together with experiments that show that addictive drugs, such as cocaine, potentiate Kv1.x channels, thereby suppressing NAc shell GABAergic activity, this hypothesis provides a mechanism by which classic hallucinogen-mediated stimulation of 5-HT2C receptors could thwart addiction. It also provides a potential reason for the non-addictive nature of classic hallucinogens.

scholarly journals Neuroplasticity and Multilevel System of Connections Determine the Integrative Role of Nucleus Accumbens in the Brain Reward System

2021 ◽  
Vol 22 (18) ◽  
pp. 9806
Author(s):  
Martyna Bayassi-Jakowicka ◽  
Grazyna Lietzau ◽  
Ewelina Czuba ◽  
Aleksandra Steliga ◽  
Monika Waśkow ◽  
...  
Keyword(s):  
Nucleus Accumbens ◽  
Complex Function ◽  
Reward System ◽  
Neurotransmitter Systems ◽  
Morphological Studies ◽  
Starting Point ◽  
Brain Reward ◽  
The Brain ◽  
Brain Reward System

A growing body of evidence suggests that nucleus accumbens (NAc) plays a significant role not only in the physiological processes associated with reward and satisfaction but also in many diseases of the central nervous system. Summary of the current state of knowledge on the morphological and functional basis of such a diverse function of this structure may be a good starting point for further basic and clinical research. The NAc is a part of the brain reward system (BRS) characterized by multilevel organization, extensive connections, and several neurotransmitter systems. The unique role of NAc in the BRS is a result of: (1) hierarchical connections with the other brain areas, (2) a well-developed morphological and functional plasticity regulating short- and long-term synaptic potentiation and signalling pathways, (3) cooperation among several neurotransmitter systems, and (4) a supportive role of neuroglia involved in both physiological and pathological processes. Understanding the complex function of NAc is possible by combining the results of morphological studies with molecular, genetic, and behavioral data. In this review, we present the current views on the NAc function in physiological conditions, emphasizing the role of its connections, neuroplasticity processes, and neurotransmitter systems.

Sign in / Sign up

Export Citation Format

Share Document