Insulin inhibits specific norepinephrine uptake in neuronal cultures from rat brain

doi:10.1016/0006-8993(86)91242-4

Brain Research

Volume 398, Issue 1, 19 November 1986, Pages 1-5

https://doi.org/10.1016/0006-8993(86)91242-4 Get rights and content

Abstract

Neuronal cells in primary culture have been demonstrated to possess specific insulin receptors (Boyd et al., J. Biol. Chem., 260 (1985) 15880–15884). Incubation of these cultures with insulin causes a dose-dependent inhibition of maprotiline-sensitive [³H]norepinephrine uptake. Maximum inhibition of 95% of maprotiline-sensitive norepinephrine uptake was observed at an insulin concentration of 167 nM with an ED₅₀ of 30 nM. Competition-inhibition and Scatchard analysis of the insulin binding data suggested that maprotiline competed for high-affinity insulin receptors. These observations suggest that both insulin and maprotiline specifically inhibit neuronal norepinephrine uptake possibly involving insulin receptors.

References (17)

F.T. Boyd et al.
Insulin receptors and modulation of norepinephrine uptake by insulin in neuronal cells in culture
J. Biol. Chem.
(1985)
D.W. Clarke et al.
Insulin binds to specific receptors and stimulates 2-deoxy-d-glucose uptake in cultured glial cells from rat brain
J. Biol. Chem.
(1984)
J. Havrankova et al.
Insulin receptors in brain
O.H. Lowry et al.
Protein measurement with folin-phenol reagent
J. Biol. Chem.
(1951)
R.A. Palovcik et al.
Insulin inhibits pyramidal neurons in hippocampal slices
Brain Research
(1984)
M.K. Raizada
Localization of insulin-like immunoreactivity in the neurons from primary cultures of rat brain
Exp. Cell Res.
(1983)
A. Sauter et al.
Effect of insulin on central catecholamines
Brain Research
(1983)
M. Barbaccia et al.
Is insulin a neuromodulator?
Adv. Biochem. Psychopharmacol.
(1982)

There are more references available in the full text version of this article.

Cited by (55)

Connecting Alzheimer's disease to diabetes: Underlying mechanisms and potential therapeutic targets
2018, Neuropharmacology
Citation Excerpt :
The existence of insulin receptors (IRs) in the brain and the functional roles for insulin signaling in the central nervous system was discovered much later (Havrankova et al., 1978). In neurons, insulin exerts neuroprotective and neurotrophic roles and regulates synaptic plasticity (Boyd et al., 1986; Huang et al., 2004; Jonas et al., 1997; Lee et al., 2005; Liu et al., 1995; Man et al., 2000; Recio-Pinto et al., 1984; Wan et al., 1997) being an important modulator of cognition (reviewed in Zhao et al., 2004). Remarkably, a number of studies revealed that the insulin signaling pathway is impaired in AD brains (Hoyer and Nitsch, 1989; Steen et al., 2005; reviewed in Craft, 2012) and in a variety of in vitro and in vivo experimental models of AD, including transgenic and non-transgenic animal models (Bomfim et al., 2012; Lourenco et al., 2013; Takeda et al., 2010).
Alzheimer's disease (AD) is a risk factor for type 2 diabetes and vice versa, and a growing body of evidence indicates that these diseases are connected both at epidemiological, clinical and molecular levels. Recent studies have begun to reveal common pathogenic mechanisms shared by AD and type 2 diabetes. Impaired neuronal insulin signaling and endoplasmic reticulum (ER) stress are present in animal models of AD, similar to observations in peripheral tissue in T2D. These findings shed light into novel diabetes-related mechanisms leading to brain dysfunction in AD. Here, we review the literature on selected mechanisms shared between these diseases and discuss how the identification of such mechanisms may lead to novel therapeutic targets in AD.
This article is part of the Special Issue entitled ‘Metabolic Impairment as Risk Factors for Neurodegenerative Disorders.’
Recruitment of GABA<inf>A</inf> receptors and fearfulness in chicks: Modulation by systemic insulin and/or epinephrine
2013, Pharmacology Biochemistry and Behavior
Citation Excerpt :
Several lines of evidence have indicated that brain insulin is partly transported rapidly from peripheral tissues via the cerebrospinal fluid and partly synthesized by neurons in the brain (Woods et al., 1985; Born et al., 2002). Previous studies have implicated a clear role for insulin, a metabolic hormone, in the regulation of the NE transporter function by inhibiting NE uptake in whole-brain neuronal cultures, dissociated brain cells, and whole-brain synaptosomes (Boyd et al., 1986; Masters et al., 1987). Intraperitoneal administration of different doses of insulin was shown to be a neuroprotective phenomenon in the brain of birds exposed to a stressful event, which increased the strength of neuroinhibition as evidenced by an increase in GABAAR (Cid et al., 2008).
One-day-old chicks were individually assessed on their latency to peck pebbles, and categorized as low latency (LL) or high latency (HL) according to fear. Interactions between acute stress and systemic insulin and epinephrine on GABA_A receptor density in the forebrain were studied. At 10 days of life, LL and HL chicks were intraperitoneally injected with insulin, epinephrine or saline, and immediately after stressed by partial water immersion for 15 min and killed by decapitation. Forebrains were dissected and the GABA_A receptor density was measured ex vivo by the ³[H]-flunitrazepam binding assay in synaptosomes. In non-stressed chicks, insulin (non-hypoglycemic dose) at 2.50 IU/kg of body weight incremented the Bmax by 40.53% in the HL chicks compared to saline group whereas no significant differences were observed between individuals in the LL subpopulation. Additionally, insulin increased the Bmax (23.48%) in the HL group with respect to the LL ones, indicating that the insulin responses were different according to the anxiety of each category. Epinephrine administration (0.25 and 0.50 mg/kg) incremented the Bmax in non-stressed chicks, in the LL group by about 37% and 33%, respectively, compared to ones injected with saline. In the stressed chicks, 0.25 mg/kg bw epinephrine increased the Bmax significantly in the HL group by about 24% compared to saline, suggesting that the effect of epinephrine was only observed in the HL group under acute stress conditions. Similarly, the same epinephrine doses co-administered with insulin increased the receptor density in both subpopulations and also showed that the highest dose of epinephrine did not further increase the maximum density of GABA_AR in HL chicks. These results suggest that systemic epinephrine, perhaps by evoking central norepinephrine release, modulated the increase in the forebrain GABA_A receptor recruitment induced by both insulin and stress in different ways depending on the subpopulation fearfulness.
Cognitive decline in STZ-3V rats is largely due to dysfunctional insulin signalling through the dentate gyrus
2012, Behavioural Brain Research
Citation Excerpt :
Blokland and Jolles [21] noticed that middle-aged intracerebroventricularly STZ-treated rats had an impaired spatial discrimination performance and exhibited a decrease in hippocampal choline acetyltransferase activity, indicating that administration of STZ to middle-aged rats provides a relevant model for dementia. Within the brain, insulin acts locally as a neuromodulator involved in neurotransmitter release, in particular that of monoamines [22,23], and in synaptic plasticity [24–26]. Insulin and insulin receptors participate in strengthening synaptic efficacy.
Recent epidemiological studies have associated type 2 diabetes mellitus with an increased risk of developing Alzheimer's disease (AD). A dramatic decrease in glucose utilisation has been observed in the brains of AD patients, and this decrease has led to the hypothesis that the cognitive dysfunction in AD is associated with decreased central glucose metabolism [1], in addition to cholinergic deficit and elevated amyloid accumulation in the brain [2]. The aims of the present study were to examine the effects of intracerebral administration of streptozotocin (STZ) on cognitive performance in rats as observed by Morris water maze (MWM) task and to clarify the successive insulin-related neurochemical changes through immunohistochemical analysis of the hippocampus. Significant differences were observed in all the parameters of the MWM task (escape latency, path efficiency, average swimming speed and swim path) between STZ-3V-treated and control rats.
Immunohistochemical analysis using hippocampal formations revealed significant decreases in phospho-cyclic AMP binding protein, Akt and insulin-degrading enzyme immunoreactivities and a significant increase in amyloid beta immunoreactivity. Our behavioural experiments confirmed that intraventricular administration of STZ led to cognitive impairment, which was ascertained by the changes in hippocampal immunohistochemical markers.
In conclusion, we demonstrated that cognitive decline in diabetes was primarily due to impaired intracerebral insulin signalling in addition to arteriosclerotic cerebrovascular changes, which hitherto have been advocated as the main cause of diabetic dementia.
Insulin signaling and addiction
2011, Neuropharmacology
Citation Excerpt :
However, initial studies of insulin’s regulation of the norepinephrine transporter (NET) function were more consistent. For example, insulin inhibits NE uptake in whole brain neuronal cultures, dissociated brain cells, and whole brain synaptosomes (Boyd et al., 1985, 1986; Masters et al., 1987; Raizada et al., 1988). Furthermore, Figlewicz et al. demonstrated that nanomolar concentrations of acute insulin decrease NE uptake from both hypothalamic and hippocampal rat slices (Figlewicz et al., 1993), and that insulin also inhibits NE uptake in PC12 cells which endogenously synthesize NE and express NET (Figlewicz et al., 1993).
Across species, the brain evolved to respond to natural rewards such as food and sex. These physiological responses are important for survival, reproduction and evolutionary processes. It is no surprise, therefore, that many of the neural circuits and signaling pathways supporting reward processes are conserved from Caenorhabditis elegans to Drosophilae, to rats, monkeys and humans. The central role of dopamine (DA) in encoding reward and in attaching salience to external environmental cues is well recognized. Less widely recognized is the role of reporters of the “internal environment”, particularly insulin, in the modulation of reward. Insulin has traditionally been considered an important signaling molecule in regulating energy homeostasis and feeding behavior rather than a major component of neural reward circuits. However, research over recent decades has revealed that DA and insulin systems do not operate in isolation from each other, but instead, work together to orchestrate both the motivation to engage in consummatory behavior and to calibrate the associated level of reward. Insulin signaling has been found to regulate DA neurotransmission and to affect the ability of drugs that target the DA system to exert their neurochemical and behavioral effects. Given that many abused drugs target the DA system, the elucidation of how dopaminergic, as well as other brain reward systems, are regulated by insulin will create opportunities to develop therapies for drug and potentially food addiction. Moreover, a more complete understanding of the relationship between DA neurotransmission and insulin may help to uncover etiological bases for “food addiction” and the growing epidemic of obesity. This review focuses on the role of insulin signaling in regulating DA homeostasis and DA signaling, and the potential impact of impaired insulin signaling in obesity and psychostimulant abuse.
This article is part of a Special Issue entitled ‘Synaptic Plasticity and Addiction’.
Regulation of monoamine transporters: Role of transporter phosphorylation
2011, Pharmacology and Therapeutics
Citation Excerpt :
Diverse biologic stimuli including neuronal activity, peptide hormones, and trophic factors have been implicated in NET regulation. Insulin regulates NE transport (Boyd et al., 1985,1986; Figlewicz et al., 1993a,b; Apparsundaram et al., 2001) and MAPKs differentially regulate NET function by trafficking dependent and independent mechanisms (Apparsundaram et al., 2001). PP2Ac blockers are also known to abolish insulin-mediated NET regulation (Apparsundaram et al., 2001).
Presynaptic biogenic amine transporters mediate reuptake of released amines from the synapse, thus regulating serotonin, dopamine and norepinephrine neurotransmission. Medications utilized in the treatment of depression, attention deficit-hyperactivity disorder and other psychiatric disorders possess high affinity for amine transporters. In addition, amine transporters are targets for psychostimulants. Altered expression of biogenic amine transporters has long been implicated in several psychiatric and degenerative disorders. Therefore, appropriate regulation and maintenance of biogenic amine transporter activity is critical for the maintenance of normal amine homoeostasis. Accumulating evidence suggests that cellular protein kinases and phosphatases regulate amine transporter expression, activity, trafficking and degradation. Amine transporters are phosphoproteins that undergo dynamic control under the influence of various kinase and phosphatase activities. This review presents a brief overview of the role of amine transporter phosphorylation in the regulation of amine transport in the normal and diseased brain. Understanding the molecular mechanisms by which phosphorylation events affect amine transporter activity is essential for understanding the contribution of transporter phosphorylation to the regulation of monoamine neurotransmission and for identifying potential new targets for the treatment of various brain diseases.
Insulin, synaptic function, and opportunities for neuroprotection
2011, Progress in Molecular Biology and Translational Science
Citation Excerpt :
Perhaps the most impactful effect of insulin on catecholamines, however, involves regulation of the transporters responsible for removing them from the synapse. Insulin has been found to inhibit NE uptake in rat pheochromocytoma (PC12) cells (a neuroendocrine cell line; Ref. 217), neuronal cultures derived from postnatal rat brain,84,218,219 synaptosomes prepared from adult rat,83 and acute hypothalamic slices.217 In contrast, insulin appeared to increase the uptake of tritiated DA by synaptosomes enriched from the rat striatal region.220
A steadily growing number of studies have begun to establish that the brain and insulin, while traditionally viewed as separate, do indeed have a relationship. The uptake of pancreatic insulin, along with neuronal biosynthesis, provides neural tissue with the hormone. As well, insulin acts upon a neuronal receptor that, although a close reflection of its peripheral counterpart, is characterized by unique structural and functional properties. One distinction is that the neural variant plays only a limited part in neuronal glucose transport. However, a number of other roles for neural insulin are gradually emerging; most significant among these is the modulation of ligand-gated ion channel (LGIC) trafficking. Notably, insulin has been shown to affect the tone of synaptic transmission by regulating cell-surface expression of inhibitory and excitatory receptors. The manner in which insulin regulates receptor movement may provide a cellular mechanism for insulin-mediated neuroprotection in the absence of hypoglycemia and stimulate the exploration of new therapeutic opportunities.

View all citing articles on Scopus

^∗: Present address: Department of Biochemistry, University of Massachusetts Medical School, Worcester, MA 01605, U.S.A.

View full text

Research reportInsulin inhibits specific norepinephrine uptake in neuronal cultures from rat brain

Abstract

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

Brain Research

Exp. Cell Res.

Brain Research

Is insulin a neuromodulator?

Adv. Biochem. Psychopharmacol.

Research report
Insulin inhibits specific norepinephrine uptake in neuronal cultures from rat brain