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Endocrine Functions of Brain Dopamine
Published in Nira Ben-Jonathan, Dopamine, 2020
Several lines of evidence show that insulin alters the activity of the VTA dopaminergic neurons and their output, depending upon the length of exposure to insulin and the state of obesity [51]. Insulin administered ICV had synergistic actions when paired with D2R antagonism to reduce sucrose consumption. Chronic hyperinsulinemia, either by a continuous ICV insulin infusion or in the hyperinsulinemic obese Fa/Fa Zucker rats, results in elevated DA transporter (DAT) mRNA in the midbrain. In addition, insulin has been shown to increase the spike frequency in about half of VTA/Substantia nigra neurons. Using fast-scan cyclic voltammetry, another study has showed that insulin can reduce evoked somato-dendritic DA in the VTA, an effect abolished by a DA transporter inhibitor [51]. The authors concluded that insulin depresses DA concentration in the VTA via increased reuptake of DA through DAT. In addition, insulin-mediated decrease of DA in the VTA may suppress salience of food once satiety is reached.
Technetium-Labeled Compounds
Published in Garimella V. S. Rayudu, Lelio G. Colombetti, Radiotracers for Medical Applications, 2019
Suresh C. Srivastava, Powell Richards
Electrochemical detection of technetium(VI) in aqueous media has accordingly been difficult because of the very rapid gain of another electron to produce technetium(V).51, 62, 63 Using very fast scan cyclic voltammetry, however, Deutsch and co-workers64 recently reported observing technetium(VI) in aqueous alkaline media and showed it to have a lifetime of the order of milliseconds. By controlled potential electrolytic reduction of TcO4− in acetonitrile, Astheimer and Schwochau65 were able to generate the violet ([CH3]4N)2TcO4 which deposited on a platinum electrode as a slightly soluble crystalline product. Most technetium(VI) compounds prepared or reported to date rapidly decompose in aqueous solutions by undergoing redox, substitution, or hydrolytic reactions depending upon the nature of the medium. Examples include TcO3,66-68 TcF6,69 TcOF4,70 etc. all of which are unstable in aqueous media. Electrochemical investigation of several technetium organometallic complexes has been carried out by Mazzocchin and co-workers71, 72 in nonaqueous media.
Abstinent Food Plans for Processed Food Addiction
Published in Joan Ifland, Marianne T. Marcus, Harry G. Preuss, Processed Food Addiction: Foundations, Assessment, and Recovery, 2017
Joan Ifland, Harry G. Preuss, Marianne T. Marcus, Wendell C. Taylor, Kathleen M. Rourke, H. Theresa Wright, Kathryn K. Sheppard
The research literature has found addictive properties for sugar in the form of tolerance and withdrawal in rats (Avena, Bocarsly, & Hoebel, 2012) and heightened cue responsivity in humans (Yau & Potenza, 2013). Addictive properties for sugar were further documented in a rat study conducted with fast-scan cyclic voltammetry. Cameron et al. found that sugar was associated with a more rapid and voluminous rise in dopamine than cocaine when administered similarly (Cameron, Wightman, & Carelli, 2014). Tunstall and Kearns showed that rats chose grain over cocaine, but they chose sugar over grain (Tunstall & Kearns, 2014). Rats have been shown to choose sugar and saccharine over heroin and cocaine (Ahmed, Guillem, & Vandaele, 2013). Wang et al. showed that sugar ingestion in the obese resulted in lower dopamine response than lean participants (Wang, Tomasi, Convit, et al., 2014), contributing to evidence for tolerance. Fowler et al. found that problematic use of sugar predicted the development of drug abuse in a population of weight-loss surgery patients (Fowler, Ivezaj, & Saules, 2014). This can be interpreted as a demonstration of transference. Fructose has also been found to have addictive properties similar to corn alcohol (Lustig, 2013). Sugar and fructose use have been found to correlate with heart disease (Preuss & Preuss, 2014; Yudkin, 1988). Fructose in breast milk was found to correlate with increased weight in infants while lactose and glucose did not (Goran, Martin, Alderete, Fujiwara, & Fields, 2017).
Adaptive, personalized closed-loop therapy for Parkinson’s disease: biochemical, neurophysiological, and wearable sensing systems
Published in Expert Review of Neurotherapeutics, 2021
Lazzaro di Biase, Gerd Tinkhauser, Eduardo Martin Moraud, Maria Letizia Caminiti, Pasquale Maria Pecoraro, Vincenzo Di Lazzaro
An alternative technique to microdialysis for biochemical sensing is electrochemical sensing (amperometry or voltammetry), this technique uses microelectrodes that are able to oxidize/reduce a molecule of interest. Electrochemical sensing can record relative changes in neurochemicals of interest, since currents generated from these reactions are correlated to the concentration of the electroactive molecules in the extracellular space [38]. Amperometry works through the measurement of current flow at a fixed constant potential. Whit this technique, the current is monitored continuously; therefore has a time resolution lower than ≤ 1 msec [38]. Fast scan cyclic voltammetry (FSCV), like all voltammetry, works similarly to amperometry through continuous measurement of current flow, but in this case, the potential is not constant but is linearly changed with respect to time. Voltammogram which is a diagram of measured current versus applied potential shows the chemical signature that allows identifying an analyte [38].
Stimuli predicting high-calorie reward increase dopamine release and drive approach to food in the absence of homeostatic need
Published in Nutritional Neuroscience, 2022
Alexander Gómez-A, Tatiana A. Shnitko, Kevin L. Caref, Saleem M. Nicola, Donita L. Robinson
On fast-scan cyclic voltammetry (FSCV) recording days, we simultaneously assessed the behavioral parameters described above and dopamine release (Δ[DA] and AUC) in the NAc, to the discriminative cue during task sessions (Figure 3). Only data from successful FSCV recordings were included in the final data set, resulting in n = 11 for the sated condition and n=10 for the hungry condition, with an overlap of 9 rats out of 12 total that were recorded under both conditions.
The impact of a high-fat diet on physical activity and dopamine neurochemistry in the striatum is sex and strain dependent in C57BL/6J and DBA/2J mice
Published in Nutritional Neuroscience, 2022
Melissa S. Totten, Conner W. Wallace, Derek M. Pierce, Steve C. Fordahl, Keith M. Erikson
The NAc of the ventral striatum is involved in the mediation of reward, satisfaction, and motivation, and has been implicated in numerous behavioral disorders, such as anxiety, obsessive-compulsive disorder, and addiction [57]. The dorsal striatum is involved in habitual and compulsive behaviors such as food-seeking and binge eating and plays a role in homeostatic energy consumption [25]. Both regions are important to consider when investigating dopamine biology as it relates to DIO. In our study, fast-scan cyclic voltammetry was used to measure real-time dopamine release and reuptake by dopamine transporter (DAT) in the striatum. While no differences in absolute levels of dopamine release in the dorsal striatum were found between groups (1P or 5P stimulations), we found that dopamine release capacity (5P:1P ratio) was significantly increased by 24% in female B6J mice fed a HFD (Figure 5(C)). Additionally, our data revealed a diet by strain interaction for dopamine reuptake in the dorsal striatum. Specifically, male and female D2J mice fed the HFD showed a decreased rate of dopamine reuptake whereas the B6J were unaffected (Figure 5(B)). Another study showed that dopamine release in the dorsal striatum was increased and dopamine clearance was decreased in male B6J mice fed a high-fat/high sugar Western style diet for 16 weeks [25]. Although our results were consistent with this study in the direction of change for dopamine release and reuptake, we did not observe these changes in B6J males. DIO and HDF-feeding studies using male and female rats have consistently reported decreases in dopamine clearance in this subregion of the striatum [63–65], which is similar to what we discovered for the D2J strain. These same rat studies also reported decreases in dopamine release; however, we found an increase in release capacity (5P:1P ratio) for B6J females and no change for the other treatment groups. It is possible that the dopamine response to a HFD is different for mice compared to rats in the dorsal striatum, although research in mice on this topic, especially in females, is currently limited.