1
|
Lin J, Rivadeneira AP, Ye Y, Ryu C, Parvin S, Jang K, Garraway SM, Choi I. Sodium Bicarbonate Decreases Alcohol Consumption in Mice. Int J Mol Sci 2024; 25:5006. [PMID: 38732226 PMCID: PMC11084513 DOI: 10.3390/ijms25095006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 04/26/2024] [Accepted: 04/28/2024] [Indexed: 05/13/2024] Open
Abstract
We previously reported that mice with low neuronal pH drink more alcohol, demonstrating the importance of pH for alcohol reward and motivation. In this study, we tested whether systemic pH affects alcohol consumption and if so, whether it occurs by changing the alcohol reward. C57BL/6J mice were given NaHCO3 to raise their blood pH, and the animals' alcohol consumption was measured in the drinking-in-the-dark and two-bottle free choice paradigms. Alcohol consumption was also assessed after suppressing the bitterness of NaHCO3 with sucrose. Alcohol reward was evaluated using a conditioned place preference. In addition, taste sensitivity was assessed by determining quinine and sucrose preference. The results revealed that a pH increase by NaHCO3 caused mice to decrease their alcohol consumption. The decrease in high alcohol contents (20%) was significant and observed at different ages, as well as in both males and females. Alcohol consumption was also decreased after suppressing NaHCO3 bitterness. Oral gavage of NaHCO3 did not alter quinine and sucrose preference. In the conditioned place preference, NaHCO3-treated mice spent less time in the alcohol-injected chamber. Conclusively, the results show that raising systemic pH with NaHCO3 decreases alcohol consumption, as it decreases the alcohol reward value.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Inyeong Choi
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA; (J.L.); (Y.Y.); (C.R.); (S.P.); (K.J.); (S.M.G.)
| |
Collapse
|
2
|
Koh AP, Smith MI, Dando R. Bitter taste function-related genes are implicated in the behavioral association between taste preference and ethanol preference in male mice. Physiol Behav 2024; 276:114473. [PMID: 38262572 DOI: 10.1016/j.physbeh.2024.114473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 01/08/2024] [Accepted: 01/19/2024] [Indexed: 01/25/2024]
Abstract
Alcohol use disorder in humans is highly heritable, and as a term is synonymous with alcoholism, alcohol dependence, and alcohol addiction. Defined by the NIAAA as a medical condition characterized by an impaired ability to stop or control alcohol use despite adverse social, occupational, or health consequences, the genetic basis of alcohol dependence is much studied. However, an intriguing component to alcohol acceptance exists outside of genetics or social factors. In fact, mice of identical genetic backgrounds without any prior experience of tasting ethanol display widely varying preferences to it, far beyond those seen for typical taste solutions. Here, we hypothesized that a preference for ethanol, which tastes both bitter and sweet to humans, would be influenced by taste function. Using a mouse model of taste behavior, we tested preferences for bitter and sweet in mice that, without training or previous experience, either preferred or avoided ethanol solutions in consumption trials. Data showed clear sex differences, in which male mice that preferred ethanol also preferred a bitter quinine solution, whereas female mice that preferred ethanol also preferred a sweet sucralose solution. Male mice preferring ethanol also exhibited lower expression levels of mRNA for genes encoding the bitter taste receptors T2R26 and T2R37, and the bitter transducing G-protein subunit GNAT3, suggesting that the higher ethanol preference observed in the male mice may be due to bitter signaling, including that arising from ethanol, being weaker in this group. Results further support links between ethanol consumption and taste response, and may be relevant to substance abuse issues in human populations.
Collapse
Affiliation(s)
- Anna P Koh
- Department of Food Science, Cornell University, Ithaca, NY 14853, United States
| | - Molly I Smith
- Department of Food Science, Cornell University, Ithaca, NY 14853, United States
| | - Robin Dando
- Department of Food Science, Cornell University, Ithaca, NY 14853, United States.
| |
Collapse
|
3
|
Santos MJ, Correia E, Vilela A. Exploring the Impact of α-Amylase Enzyme Activity and pH on Flavor Perception of Alcoholic Drinks. Foods 2023; 12:foods12051018. [PMID: 36900535 PMCID: PMC10000705 DOI: 10.3390/foods12051018] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/17/2023] [Accepted: 02/25/2023] [Indexed: 03/08/2023] Open
Abstract
The introduction of a drink in the mouth and the action of saliva and enzymes cause the perception of basic tastes and some aromas perceived in a retro-nasal way. Thus, this study aimed to evaluate the influence of the type of alcoholic beverage (beer, wine, and brandy) on lingual lipase and α-amylase activity and in-mouth pH. It was possible to see that the pH values (drink and saliva) differed significantly from the pH values of the initial drinks. Moreover, the α-amylase activity was significantly higher when the panel members tasted a colorless brandy, namely Grappa. Red wine and wood-aged brandy also induced greater α-amylase activity than white wine and blonde beer. Additionally, tawny port wine induced greater α-amylase activity than red wine. The flavor characteristics of red wines due to skin maceration and the contact of the brandy with the wood can cause a synergistic effect between beverages considered "tastier" and the activity of human α-amylase. We can conclude that saliva-beverage chemical interactions may depend on the saliva composition but also on the chemical composition of the beverage, namely its constitution in acids, alcohol concentration, and tannin content. This work is an important contribution to the e-flavor project, the development of a sensor system capable of mimicking the human perception of flavor. Furthermore, a better understanding of saliva-drink interactions allow us to comprehend which and how salivary parameters can contribute to taste and flavor perception.
Collapse
Affiliation(s)
- Maria João Santos
- Department of Agronomy, University of Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal
| | - Elisete Correia
- Center for Computational and Stochastic Mathematics (CEMAT), Department of Mathematics, University of Trás-os-Montes and Alto Douro, 5001-801 Vila Real, Portugal
| | - Alice Vilela
- Chemistry Research Centre (CQ-VR), Department of Agronomy (DAgro), School of Agrarian and Veterinary Sciences (ECAV), University of Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal
- Correspondence:
| |
Collapse
|
4
|
Perrusquia-Hernández E, Andrade-González RD, Cifuentes-Mendiola SE, Montes-Angeles CD, Zepeda-Reyes KI, Pérez-Martínez IO. Chemosensory representation of first-time oral exposure to ethanol in the orbitofrontal cortex of mice. Exp Brain Res 2023; 241:417-425. [PMID: 36571635 DOI: 10.1007/s00221-022-06529-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 12/07/2022] [Indexed: 12/27/2022]
Abstract
Intermittent ethanol consumption changes the neuronal activity of the orbitofrontal cortex (OFC) in rodents, which has been attributed to important participation in the development of addiction, particularly alcoholism. The OFC participates in gustatory sensory integration. However, it is unknown whether this region can encode chemosensory elements of oral ethanol administration independently of the consumption movement (orofacial motor response) when administered for the first time (naïve mice). To answer this question, we used a sedated mouse model and a temporary analysis protocol to register extracellular neuronal responses during the oral administration of ethanol. Our results show an increase in neuronal frequency (in the first 500 ms) when low (0.6, 1, and 2.1 M) and high (3.2, 4.3, and 8.6 M) concentrations of ethanol are orally administered. The modulatory effect of ethanol was observed from low and high concentrations and differed from the tastants. There was consistent neuronal activity independent of the concentration of ethanol. Our results demonstrate a sensory representation of oral ethanol stimulation in the OFC neurons of naïve mice under sedation.
Collapse
Affiliation(s)
- E Perrusquia-Hernández
- Sección de Neurobiología de las Sensaciones Orales, Laboratorio de Investigación Odontológica, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, San Sebastián Xhala, 54714, Cuautitlán Izcalli, Mexico.,Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina del Instituto Politécnico Nacional, Mexico City, Mexico
| | - R D Andrade-González
- Sección de Neurobiología de las Sensaciones Orales, Laboratorio de Investigación Odontológica, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, San Sebastián Xhala, 54714, Cuautitlán Izcalli, Mexico.,Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina del Instituto Politécnico Nacional, Mexico City, Mexico
| | - S E Cifuentes-Mendiola
- Sección de Osteoinmunología e Inmunidad Oral, Laboratorio de Investigación Odontológica, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - C D Montes-Angeles
- Sección de Neurobiología de las Sensaciones Orales, Laboratorio de Investigación Odontológica, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, San Sebastián Xhala, 54714, Cuautitlán Izcalli, Mexico
| | - K I Zepeda-Reyes
- Sección de Neurobiología de las Sensaciones Orales, Laboratorio de Investigación Odontológica, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, San Sebastián Xhala, 54714, Cuautitlán Izcalli, Mexico
| | - Isaac Obed Pérez-Martínez
- Sección de Neurobiología de las Sensaciones Orales, Laboratorio de Investigación Odontológica, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, San Sebastián Xhala, 54714, Cuautitlán Izcalli, Mexico.
| |
Collapse
|
5
|
Almonte AA, Cavic G, Neeman T, Enders A, Fahrer AM. Gut microbiome-depleting antibiotic regimens are not tolerated by all mouse strains: learn from (our) bitter experience. J Immunother Cancer 2022; 10:jitc-2022-005575. [PMID: 36323432 PMCID: PMC9639134 DOI: 10.1136/jitc-2022-005575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2022] [Indexed: 11/07/2022] Open
Abstract
Why the gut microbiome is critical for the success of checkpoint inhibitor cancer therapy is a question that remains unanswered, but progress has slowed. We argue that this lack of advancement is due to an unappreciated biological detail. Here, we show that the antibiotic cocktail used in seminal publications-all of which have used the C57BL/6 mouse strain-are bitter and not tolerated by other common mouse strains (ie, BALB/c and DBA/2). We write to alert readers of this important biological limitation that must be considered when planning cancer experiments investigating the gut microbiota, to prevent the unnecessary dehydration of experimental animals, and to save our colleagues valuable experimental time and resources.
Collapse
Affiliation(s)
- Andrew A Almonte
- Research School of Biology, College of Science, Australian National University, Canberra, ACT, Australia
| | - George Cavic
- Research School of Biology, College of Science, Australian National University, Canberra, ACT, Australia
| | - Teresa Neeman
- Biological Data Science Institute, College of Science, Australian National University, Canberra, ACT, Australia
| | - Anselm Enders
- John Curtin School of Medical Research, College of Health and Medicine, Australian National University, Canberra, ACT, Australia
| | - Aude M Fahrer
- Research School of Biology, College of Science, Australian National University, Canberra, ACT, Australia
| |
Collapse
|
6
|
Erikson CM, Douglas KT, Thuet TO, Richardson BD, Mohr C, Shiina H, Kaplan JS, Rossi DJ. Independent of differences in taste, B6N mice consume less alcohol than genetically similar B6J mice, and exhibit opposite polarity modulation of tonic GABA AR currents by alcohol. Neuropharmacology 2022; 206:108934. [PMID: 34933049 PMCID: PMC9208337 DOI: 10.1016/j.neuropharm.2021.108934] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 11/21/2021] [Accepted: 12/14/2021] [Indexed: 11/29/2022]
Abstract
Genetic differences in cerebellar sensitivity to alcohol (EtOH) influence EtOH consumption phenotype in animal models and contribute to risk for developing an alcohol use disorder in humans. We previously determined that EtOH enhances cerebellar granule cell (GC) tonic GABAAR currents in low EtOH consuming rodent genotypes, but suppresses it in high EtOH consuming rodent genotypes. Moreover, pharmacologically counteracting EtOH suppression of GC tonic GABAAR currents reduces EtOH consumption in high alcohol consuming C57BL/6J (B6J) mice, suggesting a causative role. In the low EtOH consuming rodent models tested to date, EtOH enhancement of GC tonic GABAAR currents is mediated by inhibition of neuronal nitric oxide synthase (nNOS) which drives increased vesicular GABA release onto GCs and a consequent enhancement of tonic GABAAR currents. Consequently, genetic variation in nNOS expression across rodent genotypes is a key determinant of whether EtOH enhances or suppresses tonic GABAAR currents, and thus EtOH consumption. We used behavioral, electrophysiological, and immunocytochemical techniques to further explore the relationship between EtOH consumption and GC GABAAR current responses in C57BL/6N (B6N) mice. B6N mice consume significantly less EtOH and achieve significantly lower blood EtOH concentrations than B6J mice, an outcome not mediated by differences in taste. In voltage-clamped GCs, EtOH enhanced the GC tonic current in B6N mice but suppressed it in B6J mice. Immunohistochemical and electrophysiological studies revealed significantly higher nNOS expression and function in the GC layer of B6N mice compared to B6Js. Collectively, our data demonstrate that despite being genetically similar, B6N mice consume significantly less EtOH than B6J mice, a behavioral difference paralleled by increased cerebellar nNOS expression and opposite EtOH action on GC tonic GABAAR currents in each genotype.
Collapse
Affiliation(s)
- Chloe M Erikson
- Department of Integrative Physiology and Neuroscience, 1815 Ferdinands Lane, Washington State University, Pullman, WA, 99164-7620, USA
| | - Kevin T Douglas
- Department of Integrative Physiology and Neuroscience, 1815 Ferdinands Lane, Washington State University, Pullman, WA, 99164-7620, USA
| | - Talia O Thuet
- Department of Integrative Physiology and Neuroscience, 1815 Ferdinands Lane, Washington State University, Pullman, WA, 99164-7620, USA
| | - Ben D Richardson
- Department of Integrative Physiology and Neuroscience, 1815 Ferdinands Lane, Washington State University, Pullman, WA, 99164-7620, USA; Department of Pharmacology, Southern Illinois University - School of Medicine, Springfield, IL, USA
| | - Claudia Mohr
- Department of Integrative Physiology and Neuroscience, 1815 Ferdinands Lane, Washington State University, Pullman, WA, 99164-7620, USA
| | - Hiroko Shiina
- Department of Integrative Physiology and Neuroscience, 1815 Ferdinands Lane, Washington State University, Pullman, WA, 99164-7620, USA; Department of Physiology, University College London, London, UK
| | - Josh S Kaplan
- Department of Psychology, Western Washington University, Bellinham, WA, 9822, USA; Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
| | - David J Rossi
- Department of Integrative Physiology and Neuroscience, 1815 Ferdinands Lane, Washington State University, Pullman, WA, 99164-7620, USA.
| |
Collapse
|
7
|
Effect of caffeine on alcohol drinking in mice. Alcohol 2021; 94:1-8. [PMID: 33781922 DOI: 10.1016/j.alcohol.2021.03.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 02/20/2021] [Accepted: 03/22/2021] [Indexed: 12/25/2022]
Abstract
Mixing alcohol (ethanol) with caffeinated beverages continues to be a common and risky practice. Energy drinks are one type of caffeinated beverage that may be especially problematic when used as mixers, due to their relatively high caffeine content in combination with their highly sweetened flavor profile. The present study used a mouse model of limited-access drinking and lickometer circuitry to examine the effects of an energy drink anid its caffeine content on ethanol consumption. Predictably, the highly sweetened energy drink significantly increased ethanol intake compared to a plain ethanol solution (6.34 ± 0.2 vs. 5.01 ± 0.3 g/kg; Cohen's d = 1.79). Interestingly, adulterating a plain ethanol solution with the same concentration of caffeine (without sweetener) found in the energy drink also increased ethanol intake (5.47 ± 0.3 vs. 4.11 ± 0.3 g/kg; Cohen's d = 1.4). A lower concentration of caffeine was without effect on ethanol drinking. Interestingly, plain caffeine solutions at both tested concentrations provoked high numbers of bottle contacts, indicating that the mice found the solution palatable. These findings suggest that altering the bitterness profile of an ethanol solution with the addition of caffeine can increase intake in a similar manner as sweetening the solution. Further, the findings underscore the importance of taste in motivating ethanol consumption and the potential role that caffeine can have in this process.
Collapse
|
8
|
Dausch Ibañez D, Hernandez Salazar LT, Laska M. Taste Responsiveness of Spider Monkeys to Dietary Ethanol. Chem Senses 2020; 44:631-638. [PMID: 31400282 DOI: 10.1093/chemse/bjz049] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Recent studies suggest that frugivorous primates might display a preference for the ethanol produced by microbia in overripe, fermenting fruit as an additional source of calories. We, therefore, assessed the taste responsiveness of 8 spider monkeys (Ateles geoffroyi) to the range of ethanol concentrations found in overripe, fermenting fruit (0.05-3.0%) and determined taste preference thresholds as well as relative taste preferences for ethanol presented in sucrose solutions and in fruit matrices, respectively. Using a 2-bottle preference test of short duration (1 min), we found that spider monkeys are able to detect ethanol concentrations as low as 0.5%, that they prefer ethanol concentrations up to 3% over water, and that they prefer sucrose solutions and pureed fruit spiked with ethanol over equimolar sucrose solutions and pureed fruit without ethanol. However, when presented with an ethanol-spiked sucrose solution and a higher-concentrated sucrose solution without ethanol, the animals clearly preferred the latter, even when the sucrose-ethanol mixture contained 3 times more calories. These results demonstrate that spider monkeys are more sensitive to the taste of ethanol than rats and humans and that they prefer ecologically relevant suprathreshold concentrations of ethanol over water. Tests with sucrose solutions and pureed fruits that were either spiked with ethanol or not suggest that sweetness may be more important for the preferences displayed by the spider monkeys than the calories provided by ethanol. The present results, therefore, do not support the notion that dietary ethanol might be used by frugivorous primates as a supplemental source of calories.
Collapse
|
9
|
Lukina EA, Murovets VO, Zolotarev VA. Experimental Anosmia Disrupts Conditioned Ethanol Aversion in the 129P3/J Inbred Mouse Strain. J EVOL BIOCHEM PHYS+ 2020. [DOI: 10.1134/s002209302001010x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
10
|
Torruella-Suárez ML, Vandenberg JR, Cogan ES, Tipton GJ, Teklezghi A, Dange K, Patel GK, McHenry JA, Hardaway JA, Kantak PA, Crowley NA, DiBerto JF, Faccidomo SP, Hodge CW, Stuber GD, McElligott ZA. Manipulations of Central Amygdala Neurotensin Neurons Alter the Consumption of Ethanol and Sweet Fluids in Mice. J Neurosci 2020; 40:632-647. [PMID: 31744862 PMCID: PMC6961987 DOI: 10.1523/jneurosci.1466-19.2019] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 10/11/2019] [Accepted: 11/04/2019] [Indexed: 12/22/2022] Open
Abstract
The central nucleus of the amygdala plays a significant role in alcohol use and other affective disorders; however, the genetically-defined neuronal subtypes and projections that govern these behaviors are not well known. Here we show that neurotensin neurons in the central nucleus of the amygdala of male mice are activated by in vivo ethanol consumption and that genetic ablation of these neurons decreases ethanol consumption and preference in non-ethanol-dependent animals. This ablation did not impact preference for sucrose, saccharin, or quinine. We found that the most robust projection of the central amygdala neurotensin neurons was to the parabrachial nucleus, a brain region known to be important in feeding behaviors, conditioned taste aversion, and alarm. Optogenetic stimulation of projections from these neurons to the parabrachial nucleus is reinforcing, and increases ethanol drinking as well as consumption of sucrose and saccharin solutions. These data suggest that this central amygdala to parabrachial nucleus projection influences the expression of reward-related phenotypes and is a novel circuit promoting consumption of ethanol and palatable fluids.SIGNIFICANCE STATEMENT Alcohol use disorder (AUD) is a major health burden worldwide. Although ethanol consumption is required for the development of AUD, much remains unknown regarding the underlying neural circuits that govern initial ethanol intake. Here we show that ablation of a population of neurotensin-expressing neurons in the central amygdala decreases intake of and preference for ethanol in non-dependent animals, whereas the projection of these neurons to the parabrachial nucleus promotes consumption of ethanol as well as other palatable fluids.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - J Andrew Hardaway
- Bowles Center for Alcohol Studies
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599
| | | | | | - Jeffrey F DiBerto
- Bowles Center for Alcohol Studies
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599
| | | | - Clyde W Hodge
- Bowles Center for Alcohol Studies
- Department of Psychiatry
| | - Garret D Stuber
- Bowles Center for Alcohol Studies
- Department of Psychiatry
- Neuroscience Center, and
| | - Zoé A McElligott
- Bowles Center for Alcohol Studies,
- Department of Psychiatry
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599
| |
Collapse
|
11
|
Novel Small-Molecule Inhibitors of Protein Kinase C Epsilon Reduce Ethanol Consumption in Mice. Biol Psychiatry 2018; 84:193-201. [PMID: 29198469 PMCID: PMC5984071 DOI: 10.1016/j.biopsych.2017.10.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 09/22/2017] [Accepted: 10/16/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND Despite the high cost and widespread prevalence of alcohol use disorders, treatment options are limited, underscoring the need for new, effective medications. Previous results using protein kinase C epsilon (PKCε) knockout mice, RNA interference against PKCε, and peptide inhibitors of PKCε predict that small-molecule inhibitors of PKCε should reduce alcohol consumption in humans. METHODS We designed a new class of PKCε inhibitors based on the Rho-associated protein kinase (ROCK) inhibitor Y-27632. In vitro kinase and binding assays were used to identify the most potent compounds. Their effects on ethanol-stimulated synaptic transmission; ethanol, sucrose, and quinine consumption; ethanol-induced loss of righting; and ethanol clearance were studied in mice. RESULTS We identified two compounds that inhibited PKCε with Ki <20 nM, showed selectivity for PKCε over other kinases, crossed the blood-brain barrier, achieved effective concentrations in mouse brain, prevented ethanol-stimulated gamma-aminobutyric acid release in the central amygdala, and reduced ethanol consumption when administered intraperitoneally at 40 mg/kg in wild-type but not in Prkce-/- mice. One compound also reduced sucrose and saccharin consumption, while the other was selective for ethanol. Both transiently impaired locomotion through an off-target effect that did not interfere with their ability to reduce ethanol intake. One compound prolonged recovery from ethanol-induced loss of righting but this was also due to an off-target effect since it was present in Prkce-/- mice. Neither altered ethanol clearance. CONCLUSIONS These results identify lead compounds for development of PKCε inhibitors that reduce alcohol consumption.
Collapse
|
12
|
|
13
|
Siciliano CA, Locke JL, Mathews TA, Lopez MF, Becker HC, Jones SR. Dopamine synthesis in alcohol drinking-prone and -resistant mouse strains. Alcohol 2017; 58:25-32. [PMID: 27425261 PMCID: PMC5684872 DOI: 10.1016/j.alcohol.2016.05.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Revised: 05/03/2016] [Accepted: 05/23/2016] [Indexed: 02/06/2023]
Abstract
Alcoholism is a prevalent and debilitating neuropsychiatric disease, and much effort has been aimed at elucidating the neurobiological mechanisms underlying maladaptive alcohol drinking in an effort to design rational treatment strategies. In preclinical literature, the use of inbred mouse lines has allowed for the examination of ethanol effects across vulnerable and resistant phenotypes. C57BL/6J mice consistently show higher rates of ethanol drinking compared to most mouse strains. Conversely, DBA/2J mice display low rates of ethanol consumption. Given that the reinforcing and rewarding effects of ethanol are thought to be in part mediated by its actions on dopamine neurotransmission, we hypothesized that alcohol-preferring C57BL/6J and alcohol-avoiding DBA/2J mice would display basal differences in dopamine system function. By administering an L-aromatic acid decarboxylase inhibitor and measuring L-Dopa accumulation via high-performance liquid chromatography as a measure of tyrosine hydroxylase activity, we found no difference in dopamine synthesis between mouse strains in the midbrain, dorsal striatum, or ventral striatum. However, we did find that quinpirole-induced inhibition of dopamine synthesis was greater in the ventral striatum of C57BL/6J mice, suggesting increased presynaptic D2-type dopamine autoreceptor sensitivity. To determine whether dopamine synthesis or autoreceptor sensitivity was altered by a history of ethanol, we exposed C57BL/6J mice to one or two weekly cycles of chronic intermittent ethanol (CIE) exposure and withdrawal. We found that there was an attenuation of baseline dopamine synthesis in the ventral striatum after two cycles of CIE. Finally, we examined tissue content of dopamine and dopamine metabolites across recombinant inbred mice bred from a C57BL/6J × DBA/2J cross (BXD). We found that low dopaminergic activity, as indicated by high dopamine/metabolite ratios, was positively correlated with drinking. Together, these findings show differential autoreceptor effects on dopamine synthesis between C57BL/6J and DBA/2J mice, and suggest that decreased dopaminergic activity is associated with excessive drinking.
Collapse
Affiliation(s)
- Cody A Siciliano
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Jason L Locke
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Tiffany A Mathews
- College of Engineering, Pennsylvania State University, University Park, PA, USA
| | - Marcelo F Lopez
- Charleston Alcohol Research Center, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA; Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA
| | - Howard C Becker
- Charleston Alcohol Research Center, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA; Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA
| | - Sara R Jones
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC, USA.
| |
Collapse
|
14
|
McGuier NS, Griffin WC, Gass JT, Padula AE, Chesler EJ, Mulholland PJ. Kv7 channels in the nucleus accumbens are altered by chronic drinking and are targets for reducing alcohol consumption. Addict Biol 2016; 21:1097-1112. [PMID: 26104325 DOI: 10.1111/adb.12279] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Alcohol use disorders (AUDs) are a major public health issue and produce enormous societal and economic burdens. Current Food and Drug Administration (FDA)-approved pharmacotherapies for treating AUDs suffer from deleterious side effects and are only effective in a subset of individuals. It is therefore essential to find improved medications for the management of AUDs. Emerging evidence suggests that anticonvulsants are a promising class of drugs for treating individuals with AUDs. In these studies, we used integrative functional genomics to demonstrate that genes that encode Kv7 channels (i.e. Kcnq2/3) are related to alcohol (ethanol) consumption, preference and acceptance in rodents. We then tested the ability of the FDA-approved anticonvulsant retigabine, a Kv7 channel opener, to reduce voluntary ethanol consumption of Wistar rats in a two-bottle choice intermittent alcohol access paradigm. Systemic administration and microinjections of retigabine into the nucleus accumbens significantly reduced alcohol drinking, and retigabine was more effective at reducing intake in high- versus low-drinking populations of Wistar rats. Prolonged voluntary drinking increased the sensitivity to the proconvulsant effects of pharmacological blockade of Kv7 channels and altered surface trafficking and SUMOylation patterns of Kv7.2 channels in the nucleus accumbens. These data implicate Kcnq2/3 in the regulation of ethanol drinking and demonstrate that long-term drinking produces neuroadaptations in Kv7 channels. In addition, these results have identified retigabine as a potential pharmacotherapy for treating AUDs and Kv7 channels as a novel therapeutic target for reducing heavy drinking.
Collapse
Affiliation(s)
- Natalie S. McGuier
- Department of Neuroscience; Medical University of South Carolina; Charleston SC USA
| | - William C. Griffin
- Department of Psychiatry and Behavioral Sciences; Medical University of South Carolina; Charleston SC USA
| | - Justin T. Gass
- Department of Neuroscience; Medical University of South Carolina; Charleston SC USA
| | - Audrey E. Padula
- Department of Neuroscience; Medical University of South Carolina; Charleston SC USA
| | | | - Patrick J. Mulholland
- Department of Neuroscience; Medical University of South Carolina; Charleston SC USA
- Department of Psychiatry and Behavioral Sciences; Medical University of South Carolina; Charleston SC USA
| |
Collapse
|
15
|
|
16
|
Sheth C, Furlong TM, Keefe KA, Taha SA. Lesion of the rostromedial tegmental nucleus increases voluntary ethanol consumption and accelerates extinction of ethanol-induced conditioned taste aversion. Psychopharmacology (Berl) 2016; 233:3737-3749. [PMID: 27549757 PMCID: PMC5063894 DOI: 10.1007/s00213-016-4406-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 08/07/2016] [Indexed: 01/06/2023]
Abstract
RATIONALE Ethanol has rewarding and aversive properties, and the balance of these properties influences voluntary ethanol consumption. Preclinical and clinical evidence show that the aversive properties of ethanol limit intake. The neural circuits underlying ethanol-induced aversion learning are not fully understood. We have previously shown that the lateral habenula (LHb), a region critical for aversive conditioning, plays an important role in ethanol-directed behaviors. However, the neurocircuitry through which LHb exerts its actions is unknown. OBJECTIVE In the present study, we investigate a role for the rostromedial tegmental nucleus (RMTg), a major LHb projection target, in regulating ethanol-directed behaviors. METHODS Rats received either sham or RMTg lesions and were studied during voluntary ethanol consumption; operant ethanol self-administration, extinction, and yohimbine-induced reinstatement of ethanol-seeking; and ethanol-induced conditioned taste aversion (CTA). RESULTS RMTg lesions increased voluntary ethanol consumption and accelerated extinction of ethanol-induced CTA. CONCLUSIONS The RMTg plays an important role in regulating voluntary ethanol consumption, possibly by mediating ethanol-induced aversive conditioning.
Collapse
Affiliation(s)
- Chandni Sheth
- Department of Pharmacology and Toxicology, University of Utah, 30 South 2000 East, Salt Lake City, UT, 84112-5820, USA.
| | - Teri M. Furlong
- Department of Pharmacology and Toxicology, University of Utah, 30 South 2000 East, Salt Lake City, UT 84112-5820 USA
| | - Kristen A. Keefe
- Department of Pharmacology and Toxicology, University of Utah, 30 South 2000 East, Salt Lake City, UT 84112-5820 USA
| | - Sharif A. Taha
- Department of Pharmacology and Toxicology, University of Utah, 30 South 2000 East, Salt Lake City, UT 84112-5820 USA
| |
Collapse
|
17
|
Ciullo DL, Dotson CD. Using Animal Models to Determine the Role of Gustatory Neural Input in the Control of Ingestive Behavior and the Maintenance of Body Weight. CHEMOSENS PERCEPT 2015; 8:61-77. [PMID: 26557212 PMCID: PMC4636125 DOI: 10.1007/s12078-015-9190-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Decades of research have suggested that nutritional intake contributes to the development of human disease, mainly by influencing the development of obesity and obesity-related conditions. A relatively large body of research indicates that functional variation in human taste perception can influence nutritional intake as well as body mass accumulation. However, there are a considerable number of studies that suggest that no link between these variables actually exists. These discrepancies in the literature likely result from the confounding influence of a variety of other, uncontrolled, factors that can influence ingestive behavior. STRATEGY In this review, the use of controlled animal experimentation to alleviate at least some of these issues related to the lack of control of experimental variables is discussed. Specific examples of the use of some of these techniques are examined. DISCUSSION AND CONCLUSIONS The review will close with some specific suggestions aimed at strengthening the link between gustatory neural input and its putative influence on ingestive behaviors and the maintenance of body weight.
Collapse
Affiliation(s)
- Dana L Ciullo
- Departments of Neuroscience and Psychiatry, Division of Addiction Medicine, University of Florida College of Medicine, and Center for Smell and Taste, University of Florida, Gainesville, FL 32611, USA,
| | - Cedrick D Dotson
- Departments of Neuroscience and Psychiatry, Division of Addiction Medicine, University of Florida College of Medicine, and Center for Smell and Taste, University of Florida, Gainesville, FL 32611, USA,
| |
Collapse
|
18
|
Nicotinic Acetylcholine Receptor (nAChR) Dependent Chorda Tympani Taste Nerve Responses to Nicotine, Ethanol and Acetylcholine. PLoS One 2015; 10:e0127936. [PMID: 26039516 PMCID: PMC4454666 DOI: 10.1371/journal.pone.0127936] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 04/20/2015] [Indexed: 12/12/2022] Open
Abstract
Nicotine elicits bitter taste by activating TRPM5-dependent and TRPM5-independent but neuronal nAChR-dependent pathways. The nAChRs represent common targets at which acetylcholine, nicotine and ethanol functionally interact in the central nervous system. Here, we investigated if the nAChRs also represent a common pathway through which the bitter taste of nicotine, ethanol and acetylcholine is transduced. To this end, chorda tympani (CT) taste nerve responses were monitored in rats, wild-type mice and TRPM5 knockout (KO) mice following lingual stimulation with nicotine free base, ethanol, and acetylcholine, in the absence and presence of nAChR agonists and antagonists. The nAChR modulators: mecamylamine, dihydro-β-erythroidine, and CP-601932 (a partial agonist of the α3β4* nAChR), inhibited CT responses to nicotine, ethanol, and acetylcholine. CT responses to nicotine and ethanol were also inhibited by topical lingual application of 8-chlorophenylthio (CPT)-cAMP and loading taste cells with [Ca2+]i by topical lingual application of ionomycin + CaCl2. In contrast, CT responses to nicotine were enhanced when TRC [Ca2+]i was reduced by topical lingual application of BAPTA-AM. In patch-clamp experiments, only a subset of isolated rat fungiform taste cells exposed to nicotine responded with an increase in mecamylamine-sensitive inward currents. We conclude that nAChRs expressed in a subset of taste cells serve as common receptors for the detection of the TRPM5-independent bitter taste of nicotine, acetylcholine and ethanol.
Collapse
|
19
|
Legastelois R, Darcq E, Wegner SA, Lombroso PJ, Ron D. Striatal-enriched protein tyrosine phosphatase controls responses to aversive stimuli: implication for ethanol drinking. PLoS One 2015; 10:e0127408. [PMID: 25992601 PMCID: PMC4438985 DOI: 10.1371/journal.pone.0127408] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 04/15/2015] [Indexed: 11/18/2022] Open
Abstract
The STriatal-Enriched protein tyrosine Phosphatase (STEP) is a brain-specific phosphatase whose dysregulation in expression and/or activity is associated with several neuropsychiatric disorders. We recently showed that long-term excessive consumption of ethanol induces a sustained inhibition of STEP activity in the dorsomedial striatum (DMS) of mice. We further showed that down-regulation of STEP expression in the DMS, and not in the adjacent dorsolateral striatum, increases ethanol intake, suggesting that the inactivation of STEP in the DMS contributes to the development of ethanol drinking behaviors. Here, we compared the consequence of global deletion of the STEP gene on voluntary ethanol intake to the consumption of an appetitive rewarding substance (saccharin) or an aversive solution (quinine or denatonium). Whereas saccharin intake was similar in STEP knockout (KO) and wild type (WT) littermate mice, the consumption of ethanol as well as quinine and denatonium was increased in STEP KO mice. These results suggested that the aversive taste of these substances was masked upon deletion of the STEP gene. We therefore hypothesized that STEP contributes to the physiological avoidance towards aversive stimuli. To further test this hypothesis, we measured the responses of STEP KO and WT mice to lithium-induced conditioned place aversion (CPA) and found that whereas WT mice developed lithium place aversion, STEP KO mice did not. In contrast, conditioned place preference (CPP) to ethanol was similar in both genotypes. Together, our results indicate that STEP contributes, at least in part, to the protection against the ingestion of aversive agents.
Collapse
Affiliation(s)
- Rémi Legastelois
- Department of Neurology, University of California San Francisco, San Francisco, California, United States of America
| | - Emmanuel Darcq
- Department of Neurology, University of California San Francisco, San Francisco, California, United States of America
| | - Scott A. Wegner
- Department of Neurology, University of California San Francisco, San Francisco, California, United States of America
| | - Paul J. Lombroso
- Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Dorit Ron
- Department of Neurology, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
| |
Collapse
|
20
|
McCool BA, Chappell AM. Chronic intermittent ethanol inhalation increases ethanol self-administration in both C57BL/6J and DBA/2J mice. Alcohol 2015; 49:111-20. [PMID: 25659650 DOI: 10.1016/j.alcohol.2015.01.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 12/30/2014] [Accepted: 01/06/2015] [Indexed: 02/01/2023]
Abstract
Inbred mouse strains provide significant opportunities to understand the genetic mechanisms controlling ethanol-directed behaviors and neurobiology. They have been specifically employed to understand cellular mechanisms contributing to ethanol consumption, acute intoxication, and sensitivities to chronic effects. However, limited ethanol consumption by some strains has restricted our understanding of clinically relevant endpoints such as dependence-related ethanol intake. Previous work with a novel tastant-substitution procedure using monosodium glutamate (MSG or umami flavor) has shown that the procedure greatly enhances ethanol consumption by mouse strains that express limited drinking phenotypes using other methods. In the current study, we employ this MSG-substitution procedure to examine how ethanol dependence, induced with passive vapor inhalation, modifies ethanol drinking in C57BL/6J and DBA/2J mice. These strains represent 'high' and 'low' drinking phenotypes, respectively. We found that the MSG substitution greatly facilitates ethanol drinking in both strains, and likewise, ethanol dependence increased ethanol consumption regardless of strain. However, DBA/2J mice exhibited greater sensitivity dependence-enhanced drinking, as represented by consumption behaviors directed at lower ethanol concentrations and relative to baseline intake levels. DBA/2J mice also exhibited significant withdrawal-associated anxiety-like behavior while C57BL/6J mice did not. These findings suggest that the MSG-substitution procedure can be employed to examine dependence-enhanced ethanol consumption across a range of drinking phenotypes, and that C57BL/6J and DBA/2J mice may represent unique neurobehavioral pathways for developing dependence-enhanced ethanol consumption.
Collapse
|
21
|
Marchal A, Marullo P, Durand C, Moine V, Dubourdieu D. Fermentative conditions modulating sweetness in dry wines: genetics and environmental factors influencing the expression level of the Saccharomyces cerevisiae HSP12 gene. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:304-311. [PMID: 25524156 DOI: 10.1021/jf504408t] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Yeast lees influence the organoleptic properties of wines by increasing their sweet taste. This effect is in part due to the protein Hsp12p, which is regulated by different stress response pathways in Saccharomyces cerevisiae. This work investigated the genetics and environmental factors influencing the expression level of the HSP12 gene in an enological context. RT-qPCR confirmed that the HSP12 expression level is regulated by temperature change and ethanol content during the alcoholic fermentation but not by the sugar content. Moreover, this gene shows an important variation according to the yeast strain used. For the first time yeast strain is demonstrated to play an important role in the perception of sweetness in red wine due to post-fermentation lees autolysis. Interestingly, a correlation between the expression level of HSP12 and the sweetness perception was found using yeast strains of different origins. All of the findings provide new insights on the contribution of yeast to wine taste.
Collapse
|
22
|
Nesil T, Kanit L, Pogun S. Bitter taste and nicotine preference: evidence for sex differences in rats. THE AMERICAN JOURNAL OF DRUG AND ALCOHOL ABUSE 2014; 41:57-67. [DOI: 10.3109/00952990.2014.990091] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
23
|
Yorgason JT, Rose JH, McIntosh JM, Ferris MJ, Jones SR. Greater ethanol inhibition of presynaptic dopamine release in C57BL/6J than DBA/2J mice: Role of nicotinic acetylcholine receptors. Neuroscience 2014; 284:854-864. [PMID: 25451295 DOI: 10.1016/j.neuroscience.2014.10.052] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 10/11/2014] [Accepted: 10/17/2014] [Indexed: 02/06/2023]
Abstract
The mesolimbic dopamine system, originating in the ventral tegmental area (VTA) and projecting to the nucleus accumbens (NAc), has been heavily implicated in the reinforcing effects of ethanol. Recent slice voltammetry studies have shown that ethanol inhibits dopamine release selectively during high-frequency activity that elicits phasic dopamine release shown to be important for learning and reinforcement. Presently, we examined ethanol inhibition of electrically evoked NAc dopamine in two mouse strains with divergent dopamine responses to ethanol, C57BL/6 (C57) and DBA/2J (DBA) mice. Previous electrophysiology and microdialysis studies have demonstrated greater ethanol-induced VTA dopaminergic firing and NAc dopamine elevations in DBA compared to C57 mice. Additionally, DBA mice have greater ethanol responses in dopamine-related behaviors, including hyperlocomotion and conditioned place preference. Currently, we demonstrate greater sensitivity of ethanol inhibition of NAc dopamine signaling in C57 compared to DBA mice. The reduced sensitivity to ethanol inhibition in DBA mice may contribute to the overall greater ethanol-induced dopamine signaling and related behaviors observed in this strain. NAc cholinergic activity is known to potently modulate terminal dopamine release. Additionally, ethanol is known to interact with multiple aspects of nicotinic acetylcholine receptor activity. Therefore, we examined ethanol-mediated inhibition of dopamine release at two ethanol concentrations (80 and 160 mM) during bath application of the non-selective nicotinic receptor antagonist mecamylamine, as well as compounds selective for the β2-(dihydro-β-erythroidine hydrobromide; DhβE) and α6-(α-conotoxin MII [H9A; L15A]) subunit-containing receptors. Mecamylamine and DhβE decreased dopamine release and reduced ethanol's inhibitory effects on dopamine in both DBA and C57 mice. Further, α-conotoxin also reduced the dopamine release and the dopamine-inhibiting effects of ethanol at the 80 mM, but not 160 mM, concentration. These data suggest that ethanol is acting in part through nicotinic acetylcholine receptors, or downstream effectors, to reduce dopamine release during high-frequency activity.
Collapse
Affiliation(s)
- J T Yorgason
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Medical Center Boulevard, Winston Salem, NC 27157, United States
| | - J H Rose
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Medical Center Boulevard, Winston Salem, NC 27157, United States
| | - J M McIntosh
- George E. Wahlen Veterans Affairs Medical Center and Departments of Psychiatry and Biology, University of Utah, Salt Lake City, UT 84108, United States
| | - M J Ferris
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Medical Center Boulevard, Winston Salem, NC 27157, United States
| | - S R Jones
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Medical Center Boulevard, Winston Salem, NC 27157, United States.
| |
Collapse
|
24
|
Brasser SM, Castro N, Feretic B. Alcohol sensory processing and its relevance for ingestion. Physiol Behav 2014; 148:65-70. [PMID: 25304192 DOI: 10.1016/j.physbeh.2014.09.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 09/29/2014] [Accepted: 09/30/2014] [Indexed: 10/24/2022]
Abstract
Alcohol possesses complex sensory attributes that are first detected by the body via sensory receptors and afferent fibers that promptly transmit signals to brain areas involved in mediating ingestive motivation, reinforcement, and addictive behavior. Given that the chemosensory cues accompanying alcohol consumption are among the most intimate, consistent, and immediate predictors of alcohol's postabsorptive effects, with experience these stimuli also gain powerful associative incentive value to elicit craving and related physiologic changes, maintenance of ongoing alcohol use, and reinstatement of drug seeking after periods of abstinence. Despite the above, preclinical research has traditionally dichotomized alcohol's taste and postingestive influences as independent regulators of motivation to drink. The present review summarizes current evidence regarding alcohol's ability to directly activate peripheral and central oral chemosensory circuits, relevance for intake of the drug, and provides a framework for moving beyond a dissociation between the sensory and postabsorptive effects of alcohol to understand their neurobiological integration and significance for alcohol addiction.
Collapse
Affiliation(s)
- Susan M Brasser
- Department of Psychology, College of Sciences, San Diego State University, San Diego, CA 92120, USA.
| | - Norma Castro
- Department of Psychology, College of Sciences, San Diego State University, San Diego, CA 92120, USA
| | - Brian Feretic
- Department of Psychology, College of Sciences, San Diego State University, San Diego, CA 92120, USA
| |
Collapse
|
25
|
Allen AL, McGeary JE, Hayes JE. Polymorphisms in TRPV1 and TAS2Rs associate with sensations from sampled ethanol. Alcohol Clin Exp Res 2014; 38:2550-60. [PMID: 25257701 DOI: 10.1111/acer.12527] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 07/21/2014] [Indexed: 01/15/2023]
Abstract
BACKGROUND Genetic variation in chemosensory genes can explain variability in individual's perception of and preference for many foods and beverages. To gain insight into variable preference and intake of alcoholic beverages, we explored individual variability in the responses to sampled ethanol (EtOH). In humans, EtOH elicits sweet, bitter, and burning sensations. Here, we explore the relationship between variation in EtOH sensations and polymorphisms in genes encoding bitter taste receptors (TAS2Rs) and a polymodal nociceptor (TRPV1). METHODS Caucasian participants (n = 93) were genotyped for 16 single nucleotide polymorphisms (SNPs) in TRPV1, 3 SNPs in TAS2R38, and 1 SNP in TAS2R13. Participants rated sampled EtOH on a generalized Labeled Magnitude Scale. Two stimuli were presented: a 16% EtOH whole-mouth sip-and-spit solution with a single time-point rating of overall intensity and a cotton swab saturated with 50% EtOH on the circumvallate papillae (CV) with ratings of multiple qualities over 3 minutes. Area-under-the-curve (AUC) was calculated for the time-intensity data. RESULTS The EtOH whole-mouth solution had overall intensity ratings near "very strong." Burning/stinging had the highest mean AUC values, followed by bitterness and sweetness. Whole-mouth intensity ratings were significantly associated with burning/stinging and bitterness AUC values on the CV. Three TRPV1 SNPs (rs224547, rs4780521, rs161364) were associated with EtOH sensations on the CV, with 2 (rs224547 and rs4780521) exhibiting strong linkage disequilibrium. Additionally, the TAS2R38 SNPs rs713598, rs1726866, and rs10246939 formed a haplotype, and were associated with bitterness on the CV. Last, overall intensity for whole-mouth EtOH associated with the TAS2R13 SNP rs1015443. CONCLUSIONS These data suggest genetic variation in TRPV1 and TAS2Rs influence sensations from sampled EtOH and may potentially influence how individuals initially respond to alcoholic beverages.
Collapse
Affiliation(s)
- Alissa L Allen
- Sensory Evaluation Center, College of Agricultural Sciences, The Pennsylvania State University, University Park, Pennsylvania; Department of Food Science, College of Agricultural Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | | | | |
Collapse
|
26
|
Stimulant and motivational effects of alcohol: Lessons from rodent and primate models. Pharmacol Biochem Behav 2014; 122:37-52. [DOI: 10.1016/j.pbb.2014.03.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 02/17/2014] [Accepted: 03/06/2014] [Indexed: 11/22/2022]
|
27
|
Barkley-Levenson AM, Crabbe JC. High drinking in the dark mice: a genetic model of drinking to intoxication. Alcohol 2014; 48:217-23. [PMID: 24360287 DOI: 10.1016/j.alcohol.2013.10.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 10/23/2013] [Accepted: 10/24/2013] [Indexed: 10/26/2022]
Abstract
Drinking to intoxication is a critical component of risky drinking behaviors in humans, such as binge drinking. Previous rodent models of alcohol consumption largely failed to demonstrate that animals were patterning drinking in such a way as to experience intoxication. Therefore, few rodent models of binge-like drinking and no specifically genetic models were available to study possible predisposing genes. The High Drinking in the Dark (HDID) selective breeding project was started to help fill this void, with HDID mice selected for reaching high blood alcohol levels in a limited access procedure. HDID mice now represent a genetic model of drinking to intoxication and can be used to help answer questions regarding predisposition toward this trait as well as potential correlated responses. They should also prove useful for the eventual development of better therapeutic strategies.
Collapse
|
28
|
McCool BA, Chappell AM. Persistent enhancement of ethanol drinking following a monosodium glutamate-substitution procedure in C57BL6/J and DBA/2J mice. Alcohol 2014; 48:55-61. [PMID: 24355071 DOI: 10.1016/j.alcohol.2013.10.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 10/29/2013] [Accepted: 10/29/2013] [Indexed: 11/17/2022]
Abstract
Inbred mouse strains such as C57BL/6J (B6) and DBA/2J (D2) and related strains have been used extensively to help identify genetic controls for a number of ethanol-related behaviors, including acute intoxication and sensitivity to repeated exposures. The disparate ethanol drinking behaviors of B6 mice expressing high-drinking/preference and D2 mice expressing low-drinking/preference have yielded considerable insight into the heritable control of alcohol drinking. However, the B6-high and D2-low drinking phenotypes are contrasted with ethanol-conditioned reward-like behaviors, which are robustly expressed by D2 mice and considerably less expressed by B6 mice. This suggests that peripheral factors, chiefly ethanol taste, may help drive ethanol drinking by these and related strains, which complicates mouse genetic studies designed to understand the relationships between reward-related behaviors and ethanol drinking. Traditional approaches such as the sucrose/saccharin-substitution procedure that normally accentuate ethanol drinking in rodents have had limited success in low drinking/preferring mice such as the D2 line. This may be due to allelic variations of the sweet taste receptor subunit, expressed by many ethanol low-drinking/preferring strains, which would limit the utility of these types of substitution approaches. We have recently shown (McCool & Chappell, 2012) that monosodium glutamate (MSG), the primary component of umami taste, can be used in a substitution procedure to initiate ethanol drinking in both B6 and D2 mice that greatly surpasses that initiated by a more traditional sucrose-substitution procedure. In this study, we show that ethanol drinking initiated by MSG substitution in D2 mice, but not sucrose substitution, can persist for several weeks following removal of the flavor. These findings further illustrate the utility of MSG substitution to initiate ethanol drinking in distinct mouse strains.
Collapse
Affiliation(s)
- Brian A McCool
- Department of Physiology & Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157 USA.
| | - Ann M Chappell
- Department of Physiology & Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157 USA
| |
Collapse
|
29
|
Bahi A, Tolle V, Fehrentz JA, Brunel L, Martinez J, Tomasetto CL, Karam SM. Ghrelin knockout mice show decreased voluntary alcohol consumption and reduced ethanol-induced conditioned place preference. Peptides 2013; 43:48-55. [PMID: 23428971 DOI: 10.1016/j.peptides.2013.02.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Revised: 02/11/2013] [Accepted: 02/11/2013] [Indexed: 02/07/2023]
Abstract
Recent work suggests that stomach-derived hormone ghrelin receptor (GHS-R1A) antagonism may reduce motivational aspects of ethanol intake. In the current study we hypothesized that the endogenous GHS-R1A agonist ghrelin modulates alcohol reward mechanisms. For this purpose ethanol-induced conditioned place preference (CPP), ethanol-induced locomotor stimulation and voluntary ethanol consumption in a two-bottle choice drinking paradigm were examined under conditions where ghrelin and its receptor were blocked, either using ghrelin knockout (KO) mice or the specific ghrelin receptor (GHS-R1A) antagonist "JMV2959". We showed that ghrelin KO mice displayed lower ethanol-induced CPP than their wild-type (WT) littermates. Consistently, when injected during CPP-acquisition, JMV2959 reduced CPP-expression in C57BL/6 mice. In addition, ethanol-induced locomotor stimulation was lower in ghrelin KO mice. Moreover, GHS-R1A blockade, using JMV2959, reduced alcohol-stimulated locomotion only in WT but not in ghrelin KO mice. When alcohol consumption and preference were assessed using the two-bottle choice test, both genetic deletion of ghrelin and pharmacological antagonism of the GHS-R1A (JMV2959) reduced voluntary alcohol consumption and preference. Finally, JMV2959-induced reduction of alcohol intake was only observed in WT but not in ghrelin KO mice. Taken together, these results suggest that ghrelin neurotransmission is necessary for the stimulatory effect of ethanol to occur, whereas lack of ghrelin leads to changes that reduce the voluntary intake as well as conditioned reward by ethanol. Our findings reveal a major, novel role for ghrelin in mediating ethanol behavior, and add to growing evidence that ghrelin is a key mediator of the effects of multiple abused drugs.
Collapse
Affiliation(s)
- Amine Bahi
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates.
| | | | | | | | | | | | | |
Collapse
|
30
|
Dotson CD, Wallace MR, Bartoshuk LM, Logan HL. Variation in the gene TAS2R13 is associated with differences in alcohol consumption in patients with head and neck cancer. Chem Senses 2012; 37:737-44. [PMID: 22824251 DOI: 10.1093/chemse/bjs063] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Variation in responsiveness to bitter-tasting compounds has been associated with differences in alcohol consumption. One strong genetic determinant of variation in bitter taste sensitivity is alleles of the TAS2R gene family, which encode chemosensory receptors sensitive to a diverse array of natural and synthetic compounds. Members of the TAS2R family, when expressed in the gustatory system, function as bitter taste receptors. To better understand the relationship between TAS2R function and alcohol consumption, we asked if TAS2R variants are associated with measures of alcohol consumption in a head and neck cancer patient cohort. Factors associated with increased alcohol intake are of strong interest to those concerned with decreasing the incidence of cancers of oral and pharyngeal structures. We found a single nucleotide polymorphism (SNP) located within the TAS2R13 gene (rs1015443 [C1040T, Ser259Asn]), which showed a significant association with measures of alcohol consumption assessed via the Alcohol Use Disorders Identification Test (AUDIT). Analyses with other SNPs in close proximity to rs1015443 suggest that this locus is principally responsible for the association. Thus, our results provide additional support to the emerging hypothesis that genetic variation in bitter taste receptors can impact upon alcohol consumption.
Collapse
Affiliation(s)
- Cedrick D Dotson
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL 32611, USA.
| | | | | | | |
Collapse
|
31
|
Gyekis JP, Dingman MA, Revitsky AR, Bryant BP, Vandenbergh DJ, Frank ME, Blizard DA. Gustatory, trigeminal, and olfactory aspects of nicotine intake in three mouse strains. Behav Genet 2012; 42:820-9. [PMID: 22618163 DOI: 10.1007/s10519-012-9546-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 05/05/2012] [Indexed: 12/16/2022]
Abstract
Studies of nicotine consumption in rodents often intend to investigate nicotine's post-absorptive effects, yet little is known about the pre-absorptive sensory experience of nicotine drinking, including gustatory, trigeminal, and olfactory influences. We conditioned taste aversion (CTA) to nicotine in males of 3 inbred mouse strains: C57BL/6J, DBA/2J, and 129X1/SvJ by repeatedly pairing 150 μg/ml nicotine drinking with lithium chloride injections. Generalization to a variety of bitter, sour, sweet, salty, and irritant solutions and to nicotine odor was then examined. Nicotine CTA generalized to the bitter stimulus quinine hydrochloride and the chemosensory irritant spilanthol in all strains. It also showed strain specificity, generalizing to hydrogen peroxide (an activator of TRPA1) in C57BL/6J mice and to the olfactory cue of nicotine in DBA/2J mice. These behavioral assays demonstrate that the sensory properties of nicotine are complex and include multiple gustatory, irritant, and olfactory components. How these qualities combine at the level of perception remains to be assessed, but sensory factors clearly exert an important influence on nicotine ingestion and their contribution to net intake of nicotine should not be neglected in animal or human studies.
Collapse
Affiliation(s)
- Joseph P Gyekis
- Department of Biobehavioral Health, Pennsylvania State University, 201 Research Building D, University Park, PA 16802, USA
| | | | | | | | | | | | | |
Collapse
|
32
|
Gautam SH, Rebello MR, Verhagen JV. Taste quality and intensity of 100 stimuli as reported by rats: the taste-location association task. Front Behav Neurosci 2012; 6:19. [PMID: 22590456 PMCID: PMC3349291 DOI: 10.3389/fnbeh.2012.00019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 04/16/2012] [Indexed: 12/04/2022] Open
Abstract
The interpretation of neural activity related to sensory stimulation requires an understanding of the subject’s perception of the stimulation. Previous methods used to evaluate the perception of chemosensory stimuli by rodents have distinct limitations. We developed a novel behavioral paradigm, the taste–location association task, to complement these methods. First we tested if rats are able to learn associations between five basic taste stimuli and their spatial locations. This spatial task was based on four prototypical tastants and water. All four rats trained to perform the task reached levels of performance well above chance. Control trials demonstrated that the rats used only taste cues. Further, the learned stimulus set was resistant to interference, allowing for generalization experiments performed subsequently. We tested the rats’ gustatory generalizations of 100 tastants to the five trained stimuli, both regarding their taste qualities as well as intensity ratings. The taste profiles generated by these experiments contribute to the understanding of how perception of the specific taste stimuli relate to the perception of the five basic taste qualities in intact behaving rats. In this large taste space we found that intensity plays a major role. Furthermore, umami stimuli were not reported as being similar to other basic tastants. Our new paradigm enables neurophysiological studies of taste-based learning and memory in awake, freely moving animals.
Collapse
Affiliation(s)
- Shree Hari Gautam
- The John B. Pierce Laboratory and the Department of Neurobiology, Yale University School of Medicine New Haven, CT, USA
| | | | | |
Collapse
|
33
|
Brasser SM, Silbaugh BC, Ketchum MJ, Olney JJ, Lemon CH. Chemosensory responsiveness to ethanol and its individual sensory components in alcohol-preferring, alcohol-nonpreferring and genetically heterogeneous rats. Addict Biol 2012; 17:423-36. [PMID: 22129513 DOI: 10.1111/j.1369-1600.2011.00415.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Alcohol activates orosensory circuits that project to motivationally relevant limbic forebrain areas that control appetite, feeding and drinking. To date, limited data exists regarding the contribution of chemosensory-derived ethanol reinforcement to ethanol preference and consumption. Measures of taste reactivity to intra-orally infused ethanol have not found differences in initial orofacial responses to alcohol between alcohol-preferring (P) and alcohol-non-preferring (NP) genetically selected rat lines. Yet, in voluntary intake tests, P rats prefer highly concentrated ethanol upon initial exposure, suggesting an early sensory-mediated attraction. Here, we directly compared self-initiated chemosensory responding for alcohol and prototypic sweet, bitter and oral trigeminal stimuli among selectively bred P, NP and non-selected Wistar (WI) outbred lines to determine whether differential sensory responsiveness to ethanol and its putative sensory components are phenotypically associated with genetically influenced alcohol preference. Rats were tested for immediate short-term lick responses to alcohol (3-40%), sucrose (0.01-1 M), quinine (0.01-3 mM) and capsaicin (0.003-1 mM) in a brief-access assay designed to index orosensory-guided behavior. P rats exhibited elevated short-term lick responses to both alcohol and sucrose relative to NP and WI lines across a broad range of concentrations of each stimulus and in the absence of blood alcohol levels that would produce significant post-absorptive effects. There was no consistent relationship between genetically mediated alcohol preference and orosensory avoidance of quinine or capsaicin. These data indicate that enhanced initial chemosensory attraction to ethanol and sweet stimuli are phenotypes associated with genetic alcohol preference and are considered within the framework of downstream activation of oral appetitive reward circuits.
Collapse
Affiliation(s)
- Susan M Brasser
- Center for Behavioral Teratology, Department of Psychology, San Diego State University, 6330 Alvarado Ct., San Diego, CA 92120, USA.
| | | | | | | | | |
Collapse
|
34
|
McCool BA, Chappell AM. Using monosodium glutamate to initiate ethanol self-administration in inbred mouse strains. Addict Biol 2012; 17:121-31. [PMID: 21054690 DOI: 10.1111/j.1369-1600.2010.00260.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Voluntary oral ethanol consumption in rodents is generally limited by strong taste-aversion in these species. Historically, this has been overcome by combining ethanol with a sweetener, typically sucrose or saccharine, and then slowly 'fading' away the sweetener. While useful in most instances, this approach has not proven as successful for some inbred strains of mice (e.g. DBA/2J) despite consistent evidence in the literature that these same strains express strong conditioned place preference for intraperitoneal- or intragastric-administered ethanol. Importantly, DBA/2J mice express a polymorphism in a 'sweet' taste receptor subunit gene that reduces the potency of sweet substances in these mice. We hypothesized that the presence of this polymorphism might help explain the contrasting behavioral findings of weak voluntary oral ethanol consumption following sucrose-fade yet robust conditioned place preference for ethanol in this strain. To test this, we compared ethanol consumption initiated by either a 'traditional' sucrose-fade or a fade from an alternative tastant, monosodium glutamate (MSG). We found that in both C57BL/6J and DBA/2J mice, the MSG-fade produced robust increases in home cage ethanol consumption relative to the traditional sucrose-fade. This increased ethanol intake following MSG-fade was evident across a range of ethanol concentrations. Our findings suggest the potential utility of the MSG-fade to establish stable voluntary oral ethanol consumption in mice, particularly ethanol 'non-preferring' strains such as DBA/2J and lend additional support to the notion that ethanol consumption in DBA/2J mice is limited by pronounced taste aversion.
Collapse
Affiliation(s)
- Brian A McCool
- Translational Center for the Neurobehavioral Study on Alcohol, Department of Physiology & Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC, USA.
| | | |
Collapse
|
35
|
Coleman J, Williams A, Phan THT, Mummalaneni S, Melone P, Ren Z, Zhou H, Mahavadi S, Murthy KS, Katsumata T, DeSimone JA, Lyall V. Strain differences in the neural, behavioral, and molecular correlates of sweet and salty taste in naive, ethanol- and sucrose-exposed P and NP rats. J Neurophysiol 2011; 106:2606-21. [PMID: 21849614 DOI: 10.1152/jn.00196.2010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Strain differences between naive, sucrose- and ethanol-exposed alcohol-preferring (P) and alcohol-nonpreferring (NP) rats were investigated in their consumption of ethanol, sucrose, and NaCl; chorda tympani (CT) nerve responses to sweet and salty stimuli; and gene expression in the anterior tongue of T1R3 and TRPV1/TRPV1t. Preference for 5% ethanol and 10% sucrose, CT responses to sweet stimuli, and T1R3 expression were greater in naive P rats than NP rats. The enhancement of the CT response to 0.5 M sucrose in the presence of varying ethanol concentrations (0.5-40%) in naive P rats was higher and shifted to lower ethanol concentrations than NP rats. Chronic ingestion of 5% sucrose or 5% ethanol decreased T1R3 mRNA in NP and P rats. Naive P rats also demonstrated bigger CT responses to NaCl+benzamil and greater TRPV1/TRPV1t expression. TRPV1t agonists produced biphasic effects on NaCl+benzamil CT responses, enhancing the response at low concentrations and inhibiting it at high concentrations. The concentration of a TRPV1/TRPV1t agonist (Maillard reacted peptides conjugated with galacturonic acid) that produced a maximum enhancement in the NaCl+benzamil CT response induced a decrease in NaCl intake and preference in P rats. In naive P rats and NP rats exposed to 5% ethanol in a no-choice paradigm, the biphasic TRPV1t agonist vs. NaCl+benzamil CT response profiles were higher and shifted to lower agonist concentrations than in naive NP rats. TRPV1/TRPV1t mRNA expression increased in NP rats but not in P rats exposed to 5% ethanol in a no-choice paradigm. We conclude that P and NP rats differ in T1R3 and TRPV1/TRPV1t expression and neural and behavioral responses to sweet and salty stimuli and to chronic sucrose and ethanol exposure.
Collapse
Affiliation(s)
- Jamison Coleman
- Dept. of Physiology and Biophysics, Virginia Commonwealth Univ., Richmond, VA 23219, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Jaholkowski P, Mierzejewski P, Zatorski P, Scinska A, Sienkiewicz-Jarosz H, Kaczmarek L, Samochowiec J, Filipkowski RK, Bienkowski P. Increased ethanol intake and preference in cyclin D2 knockout mice. GENES BRAIN AND BEHAVIOR 2011; 10:551-6. [PMID: 21429093 DOI: 10.1111/j.1601-183x.2011.00692.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Inhibitory effects of passive ethanol exposure on brain neurogenesis have been extensively documented in animal models. In contrast, a role of brain neurogenesis in ethanol self-administration has not been addressed, as yet. The aim of this study was to assess intake of, and preference for, ethanol solutions [2-16% (v/v)] in a mouse model of adult neurogenesis deficiency based on permanent knockout (KO) of cyclin D2 (Ccnd2). Wild type (WT) and Ccnd2 KO mice did not differ in 2% and 4% ethanol intake. The KO group consumed significantly more ethanol in g/kg when offered with 8% or 16% ethanol as compared with the WT controls. The WT and KO mice did not differ in 2% ethanol preference, but the KO group showed a significantly higher preference for 4-16% ethanol. Animal and human studies have suggested that the low level of response to the sedative/hypnotic effects of alcohol is genetically associated with enhanced alcohol consumption. However, in this study, there were no between-genotype differences in ethanol-induced loss of righting reflex. Previous reports have also suggested that high ethanol intake is genetically associated with the avidity for sweets and better acceptance of bitter solutions. However, the KO and WT mice consumed similar amounts of saccharin solutions and the KOs consumed less quinine (i.e. bitter) solutions as compared with the WTs. In conclusion, these results may indicate that Ccnd2 and, possibly, brain neurogenesis are involved in central regulation of ethanol intake in mice.
Collapse
Affiliation(s)
- P Jaholkowski
- Laboratory of Molecular Neurobiology, Nencki Institute, Warsaw, Poland
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Molecular targets of alcohol action: Translational research for pharmacotherapy development and screening. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 98:293-347. [PMID: 21199775 DOI: 10.1016/b978-0-12-385506-0.00007-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Alcohol abuse and dependence are multifaceted disorders with neurobiological, psychological, and environmental components. Research on other complex neuropsychiatric diseases suggests that genetically influenced intermediate characteristics affect the risk for heavy alcohol consumption and its consequences. Diverse therapeutic interventions can be developed through identification of reliable biomarkers for this disorder and new pharmacological targets for its treatment. Advances in the fields of genomics and proteomics offer a number of possible targets for the development of new therapeutic approaches. This brain-focused review highlights studies identifying neurobiological systems associated with these targets and possible pharmacotherapies, summarizing evidence from clinically relevant animal and human studies, as well as sketching improvements and challenges facing the fields of proteomics and genomics. Concluding thoughts on using results from these profiling technologies for medication development are also presented.
Collapse
|
38
|
Goulding SP, Obara I, Lominac KD, Gould AT, Miller BW, Klugmann M, Szumlinski KK. Accumbens Homer2-mediated signaling: a factor contributing to mouse strain differences in alcohol drinking? GENES BRAIN AND BEHAVIOR 2010; 10:111-26. [PMID: 20807241 DOI: 10.1111/j.1601-183x.2010.00647.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Alcohol-induced increases in nucleus accumbens glutamate actively regulate alcohol consumption, and the alcohol responsiveness of corticoaccumbens glutamate systems relates to genetic variance in alcohol reward. Here, we extend earlier data for inbred mouse strain differences in accumbens glutamate by examining for differences in basal and alcohol-induced changes in the striatal expression of glutamate-related signaling molecules between inbred C57BL/6J and DBA2/J mice. Repeated alcohol treatment (8 × 2 g/kg) increased the expression of Group1 metabotropic glutamate receptors, the NR2a/b subunits of the N-methyl-D-aspartate receptor, Homer2a/b, as well as the activated forms of protein kinase C (PKC) epsilon and phosphoinositol-3-kinase within ventral, but not dorsal, striatum. Regardless of prior alcohol experience, C57BL/6J mice exhibited higher accumbens levels of mGluR1/5, Homer2a/b, NR2a and activated kinases vs. DBA2/J mice, whereas an alcohol-induced rise in dorsal striatum mGluR1/5 expression was observed only in C57BL/6J mice. We next employed virus-mediated gene transfer approaches to ascertain the functional relevance of the observed strain difference in accumbens Homer2 expression for B6/D2 differences in alcohol-induced glutamate sensitization, as well as alcohol preference/intake. Manipulating nucleus accumbens shell Homer2b expression actively regulated these measures in C57BL/6J mice, whereas DBA2/J mice were relatively insensitive to the neurochemical and behavioral effects of virus-mediated changes in Homer2 expression. These data support the over-arching hypothesis that augmented accumbens Homer2-mediated glutamate signaling may be an endophenotype related to genetic variance in alcohol consumption. If relevant to humans, such data pose polymorphisms affecting glutamate receptor/Homer2 signaling in the etiology of alcoholism.
Collapse
Affiliation(s)
- S P Goulding
- Department of Psychology and Neuroscience Research Institute, University of California at Santa Barbara, Santa Barbara, CA 93106-9660, USA
| | | | | | | | | | | | | |
Collapse
|
39
|
Murovets VO, Zolotarev VA, Bachmanov AA. The role of the Sac locus in the alcohol taste preference in inbred mouse strains. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2010; 432:181-3. [PMID: 20665148 DOI: 10.1134/s001249661003004x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Indexed: 11/23/2022]
Affiliation(s)
- V O Murovets
- Pavlov Institute of Physiology, Russian Academy of Sciences, nab. Makarova 6, St. Petersburg, 199034, Russia
| | | | | |
Collapse
|
40
|
Sclafani A, Bahrani M, Zukerman S, Ackroff K. Stevia and saccharin preferences in rats and mice. Chem Senses 2010; 35:433-43. [PMID: 20413452 DOI: 10.1093/chemse/bjq033] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Use of natural noncaloric sweeteners in commercial foods and beverages has expanded recently to include compounds from the plant Stevia rebaudiana. Little is known about the responses of rodents, the animal models for many studies of taste systems and food intake, to stevia sweeteners. In the present experiments, preferences of female Sprague-Dawley rats and C57BL/6J mice for different stevia products were compared with those for the artificial sweetener saccharin. The stevia component rebaudioside A has the most sweetness and least off-tastes to human raters. In ascending concentration tests (48-h sweetener vs. water), rats and mice preferred a high-rebaudioside, low-stevioside extract as strongly as saccharin, but the extract stimulated less overdrinking and was much less preferred to saccharin in direct choice tests. Relative to the extract, mice drank more pure rebaudioside A and showed stronger preferences but still less than those for saccharin. Mice also preferred a commercial mixture of rebaudioside A and erythritol (Truvia). Similar tests of sweet receptor T1R3 knockout mice and brief-access licking tests with normal mice suggested that the preferences were based on sweet taste rather than post-oral effects. The preference response of rodents to stevia sweeteners is notable in view of their minimal response to some other noncaloric sweeteners (aspartame and cyclamate).
Collapse
Affiliation(s)
- Anthony Sclafani
- Department of Psychology, Brooklyn College, Brooklyn, NY 11210, USA.
| | | | | | | |
Collapse
|
41
|
Brasser SM, Norman MB, Lemon CH. T1r3 taste receptor involvement in gustatory neural responses to ethanol and oral ethanol preference. Physiol Genomics 2010; 41:232-43. [PMID: 20145204 DOI: 10.1152/physiolgenomics.00113.2009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Elevated alcohol consumption is associated with enhanced preference for sweet substances across species and may be mediated by oral alcohol-induced activation of neurobiological substrates for sweet taste. Here, we directly examined the contribution of the T1r3 receptor protein, important for sweet taste detection in mammals, to ethanol intake and preference and the neural processing of ethanol taste by measuring behavioral and central neurophysiological responses to oral alcohol in T1r3 receptor-deficient mice and their C57BL/6J background strain. T1r3 knockout and wild-type mice were tested in behavioral preference assays for long-term voluntary intake of a broad concentration range of ethanol, sucrose, and quinine. For neurophysiological experiments, separate groups of mice of each genotype were anesthetized, and taste responses to ethanol and stimuli of different taste qualities were electrophysiologically recorded from gustatory neurons in the nucleus of the solitary tract. Mice lacking the T1r3 receptor were behaviorally indifferent to alcohol (i.e., ∼50% preference values) at concentrations typically preferred by wild-type mice (5-15%). Central neural taste responses to ethanol in T1r3-deficient mice were significantly lower compared with C57BL/6J controls, a strain for which oral ethanol stimulation produced a concentration-dependent activation of sweet-responsive NTS gustatory neurons. An attenuated difference in ethanol preference between knockouts and controls at concentrations >15% indicated that other sensory and/or postingestive effects of ethanol compete with sweet taste input at high concentrations. As expected, T1r3 knockouts exhibited strongly suppressed behavioral and neural taste responses to sweeteners but did not differ from wild-type mice in responses to prototypic salt, acid, or bitter stimuli. These data implicate the T1r3 receptor in the sensory detection and transduction of ethanol taste.
Collapse
Affiliation(s)
- Susan M Brasser
- Center for Behavioral Teratology, Department of Psychology, San Diego State University, San Diego, California
| | | | | |
Collapse
|
42
|
Blednov YA, Ozburn AR, Walker D, Ahmed S, Belknap JK, Harris RA. Hybrid mice as genetic models of high alcohol consumption. Behav Genet 2010; 40:93-110. [PMID: 19798565 PMCID: PMC3038337 DOI: 10.1007/s10519-009-9298-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Accepted: 09/18/2009] [Indexed: 02/03/2023]
Abstract
We showed that F1 hybrid genotypes may provide a broader variety of ethanol drinking phenotypes than the inbred progenitor strains used to create the hybrids (Blednov et al. in Alcohol Clin Exp Res 29:1949-1958, 2005). To extend this work, we characterized alcohol consumption as well as intake of other tastants (saccharin, quinine and sodium chloride) in five inbred strains of mice (FVB, SJL, B6, BUB, NZB) and in their reciprocal F1 hybrids with B6 (FVBxB6; B6xFVB; NZBxB6; B6xNZB; BUBxB6; B6xBUB; SJLxB6; B6xSJL). We also compared ethanol intake in these mice for several concentrations before and after two periods of abstinence. F1 hybrid mice derived from the crosses of B6 and FVB and also B6 and SJL drank higher levels of ethanol than their progenitor strains, demonstrating overdominance for two-bottle choice drinking test. The B6 and NZB hybrid showed additivity in two-bottle choice drinking, whereas the hybrid of B6 and BUB demonstrated full or complete dominance. Genealogical origin, as well as non-alcohol taste preferences (sodium chloride), predicted ethanol consumption. Mice derived from the crosses of B6 and FVB showed high sustained alcohol preference and the B6 and NZB hybrids showed reduced alcohol preference after periods of abstinence. These new genetic models offer some advantages over inbred strains because they provide high, sustained, alcohol intake, and should allow mapping of loci important for the genetic architecture of these traits.
Collapse
Affiliation(s)
- Y. A. Blednov
- Waggoner Center for Alcohol and Addiction Research, University of Texas, 2500 Speedway MBB 1.124, Austin, TX 78712, USA. Waggoner Center for Alcohol and Addiction Research, 1 University Station A4800, Austin, TX 78712-0159, USA
| | - A. R. Ozburn
- Waggoner Center for Alcohol and Addiction Research, University of Texas, 2500 Speedway MBB 1.124, Austin, TX 78712, USA
| | - D. Walker
- Waggoner Center for Alcohol and Addiction Research, University of Texas, 2500 Speedway MBB 1.124, Austin, TX 78712, USA
| | - S. Ahmed
- Waggoner Center for Alcohol and Addiction Research, University of Texas, 2500 Speedway MBB 1.124, Austin, TX 78712, USA
| | - J. K. Belknap
- Portland Alcohol Research Center, Department of Veterans Affairs Medical Center and Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA
| | - R. A. Harris
- Waggoner Center for Alcohol and Addiction Research, University of Texas, 2500 Speedway MBB 1.124, Austin, TX 78712, USA
| |
Collapse
|
43
|
Abstract
OBJECTIVE Loci on mouse chromosome 2 have previously been associated with ethanol consumption. Here, we used a limited access choice paradigm in which mice consume large quantities of ethanol (2-3 g/kg/2 h) with a high preference (>80%). In addition, mouse chromosome substitution strains were used to further evaluate the contribution of chromosome 2 to ethanol consumption. METHODS AND RESULTS First, we compared the two parental inbred mouse strains, C57BL/6J and A/J, in the limited access choice paradigm for ethanol intake and ethanol preference, as well as for ethanol metabolism and taste sensitivity. Then, the effect of chromosome 2 substitution on these measures was determined. Compared with C57BL/6J mice, A/J and C57BL/6J-Chr 2/NaJ (CSS-2) mice showed profoundly reduced ethanol intake and preference. The strains were not different with regard to ethanol metabolism or taste sensitivity. Limited access ethanol consumption in F2 progeny derived from reciprocal C57BL/6J xCSS-2 and CSS-2 xC57BL/6J intercrosses and subsequent quantitative trait loci mapping identified two loci: one locus on chromosome 2 for ethanol intake and a separate locus on distal chromosome 2 for ethanol preference. This latter locus was dependent on the grandparental origin. CONCLUSION Using a limited access choice paradigm, we found that mouse chromosome 2 carries an allelic variant of a locus for ethanol intake and a distinct locus selective for ethanol preference. The heritability of alcoholism has been suggested to be parent-specific, perhaps resulting from genetic imprinting. Our findings suggest that grandparent-influenced vulnerability for ethanol consumption is conferred by genes on chromosome 2, providing important new leads to enhance our understanding of the heritability of alcoholism.
Collapse
|
44
|
Ishiwatari Y, Bachmanov AA. A high-throughput method to measure NaCl and acid taste thresholds in mice. Chem Senses 2009; 34:277-93. [PMID: 19188279 PMCID: PMC2671883 DOI: 10.1093/chemse/bjp001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/26/2008] [Indexed: 11/14/2022] Open
Abstract
To develop a technique suitable for measuring NaCl taste thresholds in genetic studies, we conducted a series of experiments with outbred CD-1 mice using conditioned taste aversion (CTA) and two-bottle preference tests. In Experiment 1, we compared conditioning procedures involving either oral self-administration of LiCl or pairing NaCl intake with LiCl injections and found that thresholds were the lowest after LiCl self-administration. In Experiment 2, we compared different procedures (30-min and 48-h tests) for testing conditioned mice and found that the 48-h test is more sensitive. In Experiment 3, we examined the effects of varying strength of conditioned (NaCl or LiCl taste intensity) and unconditioned (LiCl toxicity) stimuli and concluded that 75-150 mM LiCl or its mixtures with NaCl are the optimal stimuli for conditioning by oral self-administration. In Experiment 4, we examined whether this technique is applicable for measuring taste thresholds for other taste stimuli. Results of these experiments show that conditioning by oral self-administration of LiCl solutions or its mixtures with other taste stimuli followed by 48-h two-bottle tests of concentration series of a conditioned stimulus is an efficient and sensitive method to measure taste thresholds. Thresholds measured with this technique were 2 mM for NaCl and 1 mM for citric acid. This approach is suitable for simultaneous testing of large numbers of animals, which is required for genetic studies. These data demonstrate that mice, like several other species, generalize CTA from LiCl to NaCl, suggesting that they perceive taste of NaCl and LiCl as qualitatively similar, and they also can generalize CTA of a binary mixture of taste stimuli to mixture components.
Collapse
Affiliation(s)
- Yutaka Ishiwatari
- Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA.
| | | |
Collapse
|
45
|
Blizard DA, Vandenbergh DJ, Lionikas A, McClearn GE. Learning in the 2-Bottle Alcohol Preference Test. Alcohol Clin Exp Res 2008; 32:2041-6. [DOI: 10.1111/j.1530-0277.2008.00791.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
46
|
Cagniard B, Murphy NP. Taste reactivity and its modulation by morphine and methamphetamine in C57BL/6 and DBA/2 mice. Physiol Behav 2008; 96:412-20. [PMID: 19063906 DOI: 10.1016/j.physbeh.2008.11.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Revised: 10/29/2008] [Accepted: 11/11/2008] [Indexed: 11/30/2022]
Abstract
C57BL/6J (B6) and DBA2/J (D2) mice differ markedly in voluntary consumption of tastants and responses to abused drugs. In particular, compared to D2 mice, B6 mice avidly drink ethanol and sucrose solutions, but avoid quinine solutions. In the first study, we compared taste reactivity in B6 and D2 mice to determine the extent to which differences in drinking patterns depend on orosensory processing. Both strains showed concentration-dependent increases in positive reactions to sucrose (0.01 to 1 M). Quinine (0.03 to 3 mM) elicited concentration-dependent aversive reactions in B6 mice, whereas all reactions to quinine were virtually indistinguishable from reactions to water in D2 mice. In contrast, D2 mice reacted with relatively strong aversive responses to ethanol (5 to 30%). In the second study, we evaluated the effect of subcutaneous morphine (1 to 4 mg/kg) and methamphetamine (0.5 to 2 mg/kg) on taste reactivity to sucrose. Morphine generally decreased reactions to sucrose in both strains, suggesting a general motor depressant effect. Methamphetamine shifted sucrose responses towards aversion in both strains; particularly in D2 mice. These results suggest that strain-dependent differences in voluntary ethanol and quinine drinking depend at least partially on differences in orosensory responses. However, differences in voluntary sucrose intake may relate solely to genetic differences in post-ingestive factors. Finally, as has been suggested by previous place conditioning studies, methamphetamine appears to induce a dysphoric state in D2 mice, which may be reflected in fewer positive and more negative taste reactions to sucrose in the current study.
Collapse
Affiliation(s)
- Barbara Cagniard
- Molecular Neuropathology Group, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan.
| | | |
Collapse
|
47
|
Ellingson JM, Silbaugh BC, Brasser SM. Reduced oral ethanol avoidance in mice lacking transient receptor potential channel vanilloid receptor 1. Behav Genet 2008; 39:62-72. [PMID: 18839303 DOI: 10.1007/s10519-008-9232-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2008] [Accepted: 09/20/2008] [Indexed: 10/21/2022]
Abstract
Ethanol is a known oral trigeminal stimulant and recent data indicate that these effects are mediated in part by transient receptor potential channel vanilloid receptor 1 (TRPV1). The importance of this receptor in orally mediated ethanol avoidance is presently unknown. Here, we compared orosensory responding to ethanol in TRPV1-deficient and wild type mice in a brief-access paradigm that assesses orosensory influences by measuring immediate licking responses to small stimulus volumes. TRPV1(-/-) and control mice were tested with six concentrations of ethanol (3, 5, 10, 15, 25, 40%), capsaicin (0.003, 0.01, 0.03, 0.1, 0.3, 1 mM), sucrose (0.003, 0.01, 0.03, 0.1, 0.3, 1 M), and quinine (0.01, 0.03, 0.1, 0.3, 1, 3 mM) and psychophysical concentration-response functions were generated for each genotype and stimulus. TRPV1 knockouts displayed reduced oral avoidance responses to ethanol regardless of concentration, insensitivity to capsaicin, and little to no difference in sweet or bitter taste responding relative to wild type mice. These data indicate that the TRPV1 channel plays a role in orosensory-mediated ethanol avoidance, but that other receptor mechanisms likely also contribute to aversive oral responses to alcohol.
Collapse
Affiliation(s)
- Jarrod M Ellingson
- Center for Behavioral Teratology, Department of Psychology, San Diego State University, 6363 Alvarado Ct., Ste. 200V, San Diego, CA 92120, USA
| | | | | |
Collapse
|
48
|
Reiner DJ, Jan TA, Boughter JD, Li CX, Lu L, Williams RW, Waters RS. Genetic analysis of tongue size and taste papillae number and size in recombinant inbred strains of mice. Chem Senses 2008; 33:693-707. [PMID: 18653645 DOI: 10.1093/chemse/bjn025] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Quantitative trait loci (QTLs) analysis has been used to examine natural variation of phenotypes in the mouse somatosensory cortex, hippocampus, cerebellum, and amygdala. QTL analysis has also been utilized to map and identify genes underlying anatomical features such as muscle, organ, and body weights. However, this methodology has not been previously applied to identification of anatomical structures related to gustatory phenotypes. In this study, we used QTL analysis to map and characterize genes underlying tongue size, papillae number, and papillae area. In a set of 43 BXD recombinant inbred (RI) mice (n = 111) and 2 parental strains (C57BL/6J and DBA/2J; n = 7), we measured tongue length, width, and weight. In a subset of 23 BXD RI mice and the parental mice, we measured filiform and fungiform papillae number and fungiform papillae area. Using QTL linkage analysis (through WebQTL), we detected 2 significant and noninteracting QTLs influencing tongue length on chromosomes 5 and 7. We also found a significant QTL on chromosome 19 underlying fungiform papillae area and a suggestive QTL on chromosome 2 linked to fungiform papillae number. From these QTLs, we identified a number of candidate genes within the QTL intervals that include SRY-box containing gene, nebulin-related anchoring protein, and actin-binding LIM protein 1. This study is an important first step in identifying genetic factors underlying tongue size, papillae size, and papillae number using QTL analysis.
Collapse
Affiliation(s)
- David J Reiner
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, College of Medicine, 855 Monroe Avenue, Memphis, TN 38163, USA
| | | | | | | | | | | | | |
Collapse
|
49
|
Abstract
This review focuses on behavioral genetic studies of sweet, umami, bitter and salt taste responses in mammals. Studies involving mouse inbred strain comparisons and genetic analyses, and their impact on elucidation of taste receptors and transduction mechanisms are discussed. Finally, the effect of genetic variation in taste responsiveness on complex traits such as drug intake is considered. Recent advances in development of genomic resources make behavioral genetics a powerful approach for understanding mechanisms of taste.
Collapse
Affiliation(s)
- John D Boughter
- Department of Anatomy & Neurobiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | | |
Collapse
|
50
|
White TL, Dishaw LV, Sheehe PR, Youngentob SL. The relationship between PROP and ethanol preferences: an evaluation of 4 inbred mouse strains. Chem Senses 2007; 32:847-53. [PMID: 17693415 PMCID: PMC3435102 DOI: 10.1093/chemse/bjm053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Ethanol's taste attributes undoubtedly contribute to the development of drug preference. Ethanol's taste is both sweet and bitter. Taster status for bitter 6-n-propylthiouracil (PROP) has been proposed as a genetic marker for alcoholism; however, human results are conflicting. We collected preference scores for both tastants in 4 mouse strains selected on the basis of previously reported taste preference, with the generally accepted idea that inbred mice show minimal within-strain variation. Eighty-eight male mice (22 per strain) participated. The strains were as follows: C57BL/6J, ethanol preferring; BALB/cJ, ethanol avoiding; SWR/J, PROP avoiding; and C3HeB/FeJ, PROP neutral. Using a brief-access (1-min trials) 2-bottle preference test, we assessed the taste response of each strain to PROP and ethanol on separate days. Although PROP avoiding versus neutral mice could be segregated into significantly different populations, this was not the case for ethanol avoiding versus preferring mice, and all strains showed high variability. On average, only BALB/cJ, SWR/J, and C3HeB/FeJ mice conformed to their literature-reported preferences; nonetheless, there were a substantial number of discordant animals. C57BL/6J did not conform to previous results, indicating that they are ethanol preferring. Finally, we did not observe a significant relationship between PROP and ethanol preferences across strains. The high variability per strain and the number of animals in disagreement with their respective literature-reported preference raise concerns regarding their utility for investigations underlying mechanisms of taste-mediated ingestive responses. Absent postingestive consequences, the brief-access results suggest a possible degree of previously masked polymorphisms in taste preferences or a more recent drift in underlying genetic factors. The absence of a relationship between PROP and ethanol indicates that the bitter quality in ethanol may be more highly related to other bitter compounds that are mediated by different genetic influences.
Collapse
Affiliation(s)
- Theresa L. White
- Department of Psychology, Le Moyne College, Syracuse, NY 13214, USA
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Laura V. Dishaw
- Department of Psychology, Le Moyne College, Syracuse, NY 13214, USA
| | - Paul R. Sheehe
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
- SUNY Developmental Exposure Alcohol Research Center, Binghamton University, Binghamton, NY 13902, USA
| | - Steven L. Youngentob
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
- SUNY Developmental Exposure Alcohol Research Center, Binghamton University, Binghamton, NY 13902, USA
| |
Collapse
|