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Patel JC, Stouffer MA, Mancini M, Nicholson C, Carr KD, Rice ME. Interactions between insulin and diet on striatal dopamine uptake kinetics in rodent brain slices. Eur J Neurosci 2018; 49:794-804. [PMID: 29791756 DOI: 10.1111/ejn.13958] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 03/21/2018] [Accepted: 04/25/2018] [Indexed: 12/28/2022]
Abstract
Diet influences dopamine transmission in motor- and reward-related basal ganglia circuitry. In part, this reflects diet-dependent regulation of circulating and brain insulin levels. Activation of striatal insulin receptors amplifies axonal dopamine release in brain slices, and regulates food preference in vivo. The effect of insulin on dopamine release is indirect, and requires striatal cholinergic interneurons that express insulin receptors. However, insulin also acts directly on dopamine axons to increase dopamine uptake by promoting dopamine transporter (DAT) surface expression, counteracting enhanced dopamine release. Here, we determined the functional consequences of acute insulin exposure and chronic diet-induced changes in insulin on DAT activity after evoked dopamine release in striatal slices from adult ad-libitum fed (AL) rats and mice, and food-restricted (FR) or high-fat/high-sugar obesogenic (OB) diet rats. Uptake kinetics were assessed by fitting evoked dopamine transients to the Michaelis-Menten equation and extracting Cpeak and Vmax . Insulin (30 nm) increased both parameters in the caudate putamen and nucleus accumbens core of AL rats in an insulin receptor- and PI3-kinase-dependent manner. A pure effect of insulin on uptake was unmasked using mice lacking striatal acetylcholine, in which increased Vmax caused a decrease in Cpeak . Diet also influenced Vmax , which was lower in FR vs. AL. The effects of insulin on Cpeak and Vmax were amplified by FR but blunted by OB, consistent with opposite consequences of these diets on insulin levels and insulin receptor sensitivity. Overall, these data reveal acute and chronic effects of insulin and diet on dopamine release and uptake that will influence brain reward pathways.
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Affiliation(s)
- Jyoti C Patel
- Department of Neurosurgery, New York University School of Medicine, 550 First Avenue, New York, NY, 10016, USA
| | - Melissa A Stouffer
- Department of Neurosurgery, New York University School of Medicine, 550 First Avenue, New York, NY, 10016, USA.,Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA
| | - Maria Mancini
- Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA.,NYU Marlene and Paolo Fresco Institute on Parkinson's Disease and Movement Disorders, New York University School of Medicine, New York, NY, USA
| | - Charles Nicholson
- Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA.,NYU Neuroscience Institute, New York University School of Medicine, New York, NY, USA
| | - Kenneth D Carr
- NYU Neuroscience Institute, New York University School of Medicine, New York, NY, USA.,Psychiatry, New York University School of Medicine, New York, NY, USA.,Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Margaret E Rice
- Department of Neurosurgery, New York University School of Medicine, 550 First Avenue, New York, NY, 10016, USA.,Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA.,NYU Marlene and Paolo Fresco Institute on Parkinson's Disease and Movement Disorders, New York University School of Medicine, New York, NY, USA.,NYU Neuroscience Institute, New York University School of Medicine, New York, NY, USA
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Johnson EA, Tsai CE, Lucci J, Harrison-Shahan Y, Azzaro AJ. Dopamine D2 synthesis-modulating receptors are present in the striatum of the guinea pig. Neuropharmacology 1992; 31:95-101. [PMID: 1347405 DOI: 10.1016/0028-3908(92)90167-n] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Dopamine and selective agonists of D1 [(1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol hydrochloride, SKF 38393] and D2 [(3-[2-[N-(3-hydroxyphenylethyl)-N-propylamino]ethyl] phenol, RU 24926] receptors were examined as inhibitors of the activity of tyrosine hydroxylase in the striatum of the guinea pig. In soluble enzyme preparations, the agonists were weak inhibitors of the activity of tyrosine hydroxylase. However, the catechol-containing agonists dopamine (EC50 = 44.7 microM) and SKF 38393 (EC50 = 35.5 microM) were more potent than the non-catechol agonist RU 24926 (EC50 = 447 microM). All of the agonists were much more potent in synaptosome-rich preparations of guinea pig striatum, where stimulation of autoreceptors mediated inhibition of the enzyme (SKF 38393, D1, EC50 = 27 nM; RU 24926, D2, EC50 = 30 nM; dopamine, non-selective, EC50 = 1.5 microM). The D1 antagonist, SCH 23390 [(R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-(1H)-3- benzazepine hydrochloride], did not significantly reduce the action of SKF 38393 or dopamine. Furthermore, the D2 antagonist, (-)-sulpiride, significantly antagonized the inhibitory activity of both RU 24926 and dopamine. Studies in synaptosome-rich preparations from the striatum of the rat showed that both SKF 38393 (EC50 = 398 nM) and RU 24926 (EC50 = 58 nM) were also effective autoreceptor-mediated inhibitors of the activity of tyrosine hydroxylase in the rat. However, in the rat, SCH 23390 and (-)-sulpiride were equally effective in attenuating the inhibitory actions of dopamine.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- E A Johnson
- Department of Behavioral Medicine, West Virginia University, Morgantown 26506
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Vulto AG, Sharp T, Ungerstedt U, Versteeg DH. Rapid postmortem increase in extracellular dopamine in the rat brain as assessed by brain microdialysis. J Neurochem 1988; 51:746-9. [PMID: 3411324 DOI: 10.1111/j.1471-4159.1988.tb01808.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Extracellular dopamine (DA) and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in rat nucleus accumbens were determined before and shortly following death using microdialysis. A maximal 400-fold increase in the output of DA was observed within the first 5 min of death. DA output remained elevated over the following hour at a level of approximately 70-fold above pre-death values. In contrast to that of DA, DOPAC and HVA output gradually declined. Before death the extracellular DOPAC/DA ratio was about 250; after death this ratio dropped to 0.44 at 5 min. These observations may have important implications for experiments measuring the output of (endogenous) DA and its metabolites from brain tissue in vitro: autoregulation of, e.g., transmitter release and synthesis in vitro may be seriously disrupted by the observed depletion of transmitter storage granules.
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Affiliation(s)
- A G Vulto
- Department of Pharmacology, Karolinska Institute, Stockholm, Sweden
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