1
|
Chen W. Neural circuits provide insights into reward and aversion. Front Neural Circuits 2022; 16:1002485. [PMID: 36389177 PMCID: PMC9650032 DOI: 10.3389/fncir.2022.1002485] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 10/12/2022] [Indexed: 01/07/2023] Open
Abstract
Maladaptive changes in the neural circuits associated with reward and aversion result in some common symptoms, such as drug addiction, anxiety, and depression. Historically, the study of these circuits has been hampered by technical limitations. In recent years, however, much progress has been made in understanding the neural mechanisms of reward and aversion owing to the development of technologies such as cell type-specific electrophysiology, neuronal tracing, and behavioral manipulation based on optogenetics. The aim of this paper is to summarize the latest findings on the mechanisms of the neural circuits associated with reward and aversion in a review of previous studies with a focus on the ventral tegmental area (VTA), nucleus accumbens (NAc), and basal forebrain (BF). These findings may inform efforts to prevent and treat mental illnesses associated with dysfunctions of the brain's reward and aversion system.
Collapse
|
2
|
Moaddab M, Ray MH, McDannald MA. Ventral pallidum neurons dynamically signal relative threat. Commun Biol 2021; 4:43. [PMID: 33420332 PMCID: PMC7794503 DOI: 10.1038/s42003-020-01554-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 12/01/2020] [Indexed: 12/11/2022] Open
Abstract
The ventral pallidum (VP) is anatomically poised to contribute to threat behavior. Recent studies report a VP population that scales firing increases to reward but decreases firing to aversive cues. Here, we tested whether firing decreases in VP neurons serve as a neural signal for relative threat. Single-unit activity was recorded while male rats discriminated cues predicting unique foot shock probabilities. Rats' behavior and VP single-unit firing discriminated danger, uncertainty, and safety cues. Two populations of VP neurons dynamically signaled relative threat, decreasing firing according to foot shock probability during early cue presentation, but disproportionately decreasing firing to uncertain threat as foot shock drew near. One relative threat population increased firing to reward, consistent with a bi-directional signal for general value. The second population was unresponsive to reward, revealing a specific signal for relative threat. The results reinforce anatomy to reveal the VP as a neural source of a dynamic, relative threat signal.
Collapse
Affiliation(s)
- Mahsa Moaddab
- Department of Psychology and Neuroscience, Boston College, 140 Commonwealth Avenue 514 McGuinn Hall, Chestnut Hill, MA, USA.
| | - Madelyn H Ray
- Department of Psychology and Neuroscience, Boston College, 140 Commonwealth Avenue 514 McGuinn Hall, Chestnut Hill, MA, USA
| | - Michael A McDannald
- Department of Psychology and Neuroscience, Boston College, 140 Commonwealth Avenue 514 McGuinn Hall, Chestnut Hill, MA, USA.
| |
Collapse
|
3
|
Berta B, Kertes E, Péczely L, Ollmann T, László K, Gálosi R, Kállai V, Petykó Z, Zagorácz O, Kovács A, Karádi Z, Lénárd L. Ventromedial prefrontal cortex is involved in preference and hedonic evaluation of tastes. Behav Brain Res 2019; 367:149-157. [PMID: 30940513 DOI: 10.1016/j.bbr.2019.03.051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/29/2019] [Accepted: 03/29/2019] [Indexed: 01/01/2023]
Abstract
The ventromedial prefrontal cortex (vmPFC) of rats has reciprocal connections with the gustatory and the hedonic impact coding structures. The main goal of the present study was to investigate the involvement of local neurons of vmPFC and their catecholaminergic innervations in taste preference and taste reactivity test. Therefore, kainate or 6-hydroxydopamine (6-OHDA) lesions were performed in the vmPFC by iontophoretic method. In the first experiment, taste preference was tested to 250 mM and 500 mM glucose solutions over water in two-bottle choice test. In the second experiment, taste reactivity was examined to 4 concentrations of glucose solutions (250 mM, 500 mM, 750 mM and 1000 mM) and 4 concentrations of quinine solutions (0.125 mM, 0.25 mM, 1.25 mM and 2.5 mM). Our results showed, that kainate microlesion of vmPFC did not modify the preference of 250 mM and 500 mM glucose solutions in two-bottle choice test. In contrast, 6-OHDA microlesion of vmPFC resulted in increased preference to the higher concentration of glucose (500 mM) solution over water. Results of taste reactivity test showed that kainate lesion resulted in more ingestive and less rejective responses to 750 mM glucose solution and elevated rejectivity to the higher concentrations (1.25 mM and 2.5 mM) of quinine solutions. 6-OHDA lesion of vmPFC increased the number of ingestive responses to highly concentrated (500 mM, 750 mM and 1000 mM) glucose solutions and decreased the number of ingestive responses to the lower concentration (0.125 mM) of quinine solution. The present data provide evidence for the important role of vmPFC neurons and catecholaminergic innervation of the vmPFC in the regulation of hedonic evaluation of tastes and in the hedonic consummatory behavior.
Collapse
Affiliation(s)
- Beáta Berta
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Erika Kertes
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - László Péczely
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Tamás Ollmann
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Kristóf László
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Rita Gálosi
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Veronika Kállai
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Zoltán Petykó
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary; Molecular Neuroendocrinology Research Group, Szentágothai Research Center, Pécs University, Pécs, Hungary
| | - Olga Zagorácz
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Anita Kovács
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Zoltán Karádi
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary; Molecular Neuroendocrinology Research Group, Szentágothai Research Center, Pécs University, Pécs, Hungary
| | - László Lénárd
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary; Molecular Neuroendocrinology Research Group, Szentágothai Research Center, Pécs University, Pécs, Hungary.
| |
Collapse
|
4
|
The Basolateral Nucleus of the Amygdala Executes the Parallel Processes of Avoidance and Palatability in the Retrieval of Conditioned Taste Aversion in Male Rats. eNeuro 2019; 6:ENEURO.0004-19.2019. [PMID: 31235467 PMCID: PMC6620391 DOI: 10.1523/eneuro.0004-19.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 04/03/2019] [Accepted: 04/26/2019] [Indexed: 12/25/2022] Open
Abstract
Conditioned taste aversion (CTA) is an essential behavior for animal survival. Conditioned animals show avoidance and decreased palatability to a conditioned stimulus (CS) on CTA retrieval. In this study, we aimed to determine whether the basolateral nucleus of the amygdala (BLA) is involved in CTA retrieval and whether avoidance and palatability in CTA retrieval are processed in the BLA. We developed an experimental chamber for time-course analysis of the behavior to approach a spout and lick a CS. In this experimental chamber, we analyzed the behavior of male rats following microinjections of GABAA receptor agonist muscimol or saline into the BLA. The rats showed two types of approach behavior: they either (1) approached and licked the spout or (2) approached but did not lick the spout. Muscimol injection into the BLA decreased the frequency of the latter type of approach behavior, indicating that BLA inactivation reduced avoidance to the CS. The muscimol injection into the BLA also significantly increased the consumption of the CS. Lick microstructure analysis demonstrated that intra-BLA muscimol significantly increased licking burst number and size, indicating that BLA inactivation attenuated aversion to the CS as large burst licking is an indicator of high palatability. These results suggest that the increase in CS consumption with intra-BLA muscimol injection was due to alterations in approach and aversive responses to the CS. Therefore, we conclude that the BLA plays an essential role in CTA retrieval by parallel processing of avoidance and palatability.
Collapse
|
5
|
Tanaka DH, Li S, Mukae S, Tanabe T. Genetic Access to Gustatory Disgust-Associated Neurons in the Interstitial Nucleus of the Posterior Limb of the Anterior Commissure in Male Mice. Neuroscience 2019; 413:45-63. [PMID: 31229633 DOI: 10.1016/j.neuroscience.2019.06.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 06/12/2019] [Accepted: 06/14/2019] [Indexed: 12/18/2022]
Abstract
Orofacial and somatic disgust reactions are observed in rats following intraoral infusion of not only bitter quinine (innate disgust) but also sweet saccharin previously paired with illness (learned disgust). It remains unclear, however, whether these innate and learned disgust reactions share a common neural basis and which brain regions, if any, host it. In addition, there is no established method to genetically access neurons whose firing is associated with disgust (disgust-associated neurons). Here, we examined the expression of cFos and Arc, two markers of neuronal activity, in the interstitial nucleus of the posterior limb of the anterior commissure (IPAC) of male mice that showed innate disgust and mice that showed learned disgust. Furthermore, we used a targeted recombination in active populations (TRAP) method to genetically label the disgust-associated neurons in the IPAC with YFP. We found a significant increase of both cFos-positive neurons and Arc-positive neurons in the IPAC of mice that showed innate disgust and mice that showed learned disgust. In addition, TRAP following quinine infusion (Quinine-TRAP) resulted in significantly more YFP-positive neurons in the IPAC, compared to TRAP following water infusion. A significant number of the YFP-positive neurons following Quinine-TRAP were co-labeled with Arc following the second quinine infusion, confirming that Quinine-TRAP preferentially labeled quinine-activated neurons in the IPAC. Our results suggest that the IPAC activity is associated with both innate and learned disgust and that disgust-associated neurons in the IPAC are genetically accessible by TRAP.
Collapse
Affiliation(s)
- Daisuke H Tanaka
- Department of Pharmacology and Neurobiology, Graduate School of Medicine, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Shusheng Li
- Department of Pharmacology and Neurobiology, Graduate School of Medicine, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Shiori Mukae
- Department of Pharmacology and Neurobiology, Graduate School of Medicine, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
| | - Tsutomu Tanabe
- Department of Pharmacology and Neurobiology, Graduate School of Medicine, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
| |
Collapse
|
6
|
Rock EM, Limebeer CL, Aliasi-Sinai L, Parker LA. The ventral pallidum as a critical region for fatty acid amide hydrolase inhibition of nausea-induced conditioned gaping in male Sprague-Dawley rats. Neuropharmacology 2019; 155:142-149. [PMID: 31145905 DOI: 10.1016/j.neuropharm.2019.05.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/15/2019] [Accepted: 05/23/2019] [Indexed: 12/21/2022]
Abstract
Here we investigate the involvement of the ventral pallidum (VP) in the anti-nausea effect of fatty acid amide hydrolase (FAAH) inhibition with PF-3845, and examine the pharmacological mechanism of such an effect. We explored the potential of intra-VP PF-3845 to reduce the establishment of lithium chloride (LiCl)-induced conditioned gaping (a model of acute nausea) in male Sprague-Dawley rats. As well, the role of the cannabinoid 1 (CB1) receptors and the peroxisome proliferator-activated receptors-α (PPARα) in the anti-nausea effect of PF-3845 was examined. Finally, the potential of intra-VP GW7647, a PPARα agonist, to reduce acute nausea was also evaluated. Intra-VP PF-3845 dose-dependently reduced acute nausea by a PPARα mechanism (and not a CB1 receptor mechanism). Intra-VP administration of GW7647, similarly attenuated acute nausea. These findings suggest that the anti-nausea action of FAAH inhibition may occur in the VP, and may involve activation of PPARα to suppress acute nausea.
Collapse
Affiliation(s)
- Erin M Rock
- Department of Psychology and Neuroscience Graduate Program, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| | - Cheryl L Limebeer
- Department of Psychology and Neuroscience Graduate Program, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| | - Lital Aliasi-Sinai
- Department of Psychology and Neuroscience Graduate Program, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| | - Linda A Parker
- Department of Psychology and Neuroscience Graduate Program, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada.
| |
Collapse
|
7
|
Schier LA, Spector AC. The Functional and Neurobiological Properties of Bad Taste. Physiol Rev 2019; 99:605-663. [PMID: 30475657 PMCID: PMC6442928 DOI: 10.1152/physrev.00044.2017] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 05/18/2018] [Accepted: 06/30/2018] [Indexed: 12/12/2022] Open
Abstract
The gustatory system serves as a critical line of defense against ingesting harmful substances. Technological advances have fostered the characterization of peripheral receptors and have created opportunities for more selective manipulations of the nervous system, yet the neurobiological mechanisms underlying taste-based avoidance and aversion remain poorly understood. One conceptual obstacle stems from a lack of recognition that taste signals subserve several behavioral and physiological functions which likely engage partially segregated neural circuits. Moreover, although the gustatory system evolved to respond expediently to broad classes of biologically relevant chemicals, innate repertoires are often not in register with the actual consequences of a food. The mammalian brain exhibits tremendous flexibility; responses to taste can be modified in a specific manner according to bodily needs and the learned consequences of ingestion. Therefore, experimental strategies that distinguish between the functional properties of various taste-guided behaviors and link them to specific neural circuits need to be applied. Given the close relationship between the gustatory and visceroceptive systems, a full reckoning of the neural architecture of bad taste requires an understanding of how these respective sensory signals are integrated in the brain.
Collapse
Affiliation(s)
- Lindsey A Schier
- Department of Biological Sciences, University of Southern California , Los Angeles, California ; and Department of Psychology and Program in Neuroscience, Florida State University , Tallahassee, Florida
| | - Alan C Spector
- Department of Biological Sciences, University of Southern California , Los Angeles, California ; and Department of Psychology and Program in Neuroscience, Florida State University , Tallahassee, Florida
| |
Collapse
|
8
|
Berta B, Péczely L, Kertes E, Petykó Z, Ollmann T, László K, Kállai V, Kovács A, Zagorácz O, Gálosi R, Karádi Z, Lénárd L. Iontophoretic microlesions with kainate or 6-hydroxidopamine in ventromedial prefrontal cortex result in deficit in conditioned taste avoidance to palatable tastants. Brain Res Bull 2018; 143:106-115. [PMID: 30347263 DOI: 10.1016/j.brainresbull.2018.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 09/12/2018] [Accepted: 10/04/2018] [Indexed: 02/08/2023]
Abstract
Effects of kainate or 6-hydroxidopamine (6-OHDA) lesions in the ventromedial prefrontal cortex (vmPFC) on taste-related learning and memory processes were examined. Neurotoxins were applied by iontophoretic method to minimize the extent of lesion and the side effects. Acquisition and retention of conditioned taste avoidance (CTA) was tested to different taste stimuli (0.05 M NaCl, 0.01 M saccharin, 0.01 M citrate and 0.00025 M quinine). In the first experiment, palatability index of taste solutions with these concentrations has been determined as strongly palatable (NaCl, saccharin), weakly palatable (citrate) and weakly unpalatable (quinine) taste stimuli. In two other experiments vmPFC lesions were performed before CTA (acquisition) or after CTA (retrieval). Our results showed that both kainate and 6-OHDA microlesions of vmPFC resulted in deficit of CTA acquisition (to NaCl, saccharin and citrate) and retrieval (to NaCl and saccharin). Deficits were specific to palatable tastants, particularly those that are strongly palatable, and did not occur for unpalatable stimulus. The present data provide evidence for the important role of vmPFC neurons and catecholaminergic innervation of the vmPFC in taste related learning and memory processes.
Collapse
Affiliation(s)
- Beáta Berta
- Institute of Physiology, Medical School, Pécs University, Pécs Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - László Péczely
- Institute of Physiology, Medical School, Pécs University, Pécs Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Erika Kertes
- Institute of Physiology, Medical School, Pécs University, Pécs Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Zoltán Petykó
- Institute of Physiology, Medical School, Pécs University, Pécs Hungary; Neuroscience Center, Pécs University, Pécs, Hungary; Molecular Neuroendocrinology Research Group, Szentágothai Research Center, Pécs University, Pécs, Hungary
| | - Tamás Ollmann
- Institute of Physiology, Medical School, Pécs University, Pécs Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Kristóf László
- Institute of Physiology, Medical School, Pécs University, Pécs Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Veronika Kállai
- Institute of Physiology, Medical School, Pécs University, Pécs Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Anita Kovács
- Institute of Physiology, Medical School, Pécs University, Pécs Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Olga Zagorácz
- Institute of Physiology, Medical School, Pécs University, Pécs Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Rita Gálosi
- Institute of Physiology, Medical School, Pécs University, Pécs Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Zoltán Karádi
- Institute of Physiology, Medical School, Pécs University, Pécs Hungary; Neuroscience Center, Pécs University, Pécs, Hungary; Molecular Neuroendocrinology Research Group, Szentágothai Research Center, Pécs University, Pécs, Hungary
| | - László Lénárd
- Institute of Physiology, Medical School, Pécs University, Pécs Hungary; Neuroscience Center, Pécs University, Pécs, Hungary; Molecular Neuroendocrinology Research Group, Szentágothai Research Center, Pécs University, Pécs, Hungary.
| |
Collapse
|
9
|
Wulff AB, Tooley J, Marconi LJ, Creed MC. Ventral pallidal modulation of aversion processing. Brain Res 2018; 1713:62-69. [PMID: 30300634 DOI: 10.1016/j.brainres.2018.10.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 09/27/2018] [Accepted: 10/05/2018] [Indexed: 12/23/2022]
Abstract
Responding to aversive and rewarding stimuli is essential to survival. The ventral pallidum (VP) is a critical node in the mesolimbic network, being the primary output of the nucleus accumbens and projecting to the lateral habenula (LHb) and ventral tegmental area (VTA). The VP is thus poised to modulate the habenula-tegmental circuitry and contribute to processing both rewarding and aversive stimuli. Here, we integrate human functional imaging, behavioral pharmacology in rodents, and recent optogenetic circuit dissection studies of the VP with a focus on the role of the neurochemically-distinct subpopulations in aversion processing. These recent results support a model in which glutamatergic VP neurons play a unique role in aversion processing, while canonical GABAergic VP neurons promote reinforcement and encode the hedonic value of reward. Genetic ablation of glutamatergic, but not GABAergic VP neurons abolishes devaluation of natural reward (sucrose) by pairing with an aversive stimulus (lithium chloride injection). Both of these populations modulate activity throughout the LHb and VTA, which is necessary for expression of adaptive behavior in response to rewarding or aversive stimuli. Future work will address how neuromodulators such as endogenous opioids or dopamine shape function and plasticity within these distinct populations of VP neurons, when these subpopulations are engaged during learning responses to rewarding and aversive stimuli, and how their activity is altered in models of reward-related disorders. Answering these questions will be necessary to understand the basis and ultimately develop targeted therapies for disorders of reward/aversion processing, such as affective, chronic pain and substance use disorders.
Collapse
Affiliation(s)
- Andreas B Wulff
- University of Maryland School of Medicine, Department of Pharmacology, United States
| | - Jessica Tooley
- Washington University School of Medicine in St. Louis, Department of Anesthesiology, United States; University of Maryland School of Medicine, Department of Pharmacology, United States
| | - Lauren J Marconi
- University of Maryland School of Medicine, Department of Pharmacology, United States
| | - Meaghan C Creed
- Washington University School of Medicine in St. Louis, Department of Anesthesiology, United States
| |
Collapse
|
10
|
Inui T, Shimura T. Activation of mu-opioid receptors in the ventral pallidum decreases the negative hedonic evaluation of a conditioned aversive taste in rats. Behav Brain Res 2016; 320:391-399. [PMID: 27825896 DOI: 10.1016/j.bbr.2016.10.051] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 10/18/2016] [Accepted: 10/21/2016] [Indexed: 12/21/2022]
Abstract
Conditioned taste aversion (CTA) causes a shift in the hedonic evaluation of a conditioned stimulus (CS) from positive to negative, and reduces the CS intake. Mu-opioid receptors (MORs) in the ventral pallidum (VP) are known to be involved in the hedonic evaluation of positive rewarding stimuli; however, their involvement in evaluation of a negative aversive stimulus is still unclear. To explore the neural mechanisms of the negative hedonic evaluation of the CS in CTA, we examined the effects of the activation of VP MORs on the behavioral responses of rats to a CS. Rats implanted with guide cannulae into the bilateral VP received a pairing of 5mM saccharin solution as a CS with an intraperitoneal injection of 0.15M lithium chloride as an unconditioned stimulus. On the test day, after microinjections of MOR agonist [D-Ala2, N-MePhe4, Gly-ol]-enkephalin (DAMGO) into the VP, we observed the behavioral responses to the intraorally infused CS solution. The DAMGO injections caused a larger number of ingestive taste reactivity responses to the CS solution. We also measured the consumption of the CS solution in a separate group of rats, using a single-bottle test. The DAMGO injected rats drank a higher volume of the CS solution than the saline injected rats. These results indicate that the activation of MORs in the VP results in the attenuation of aversion to the CS solution, thereby inducing the larger CS intake. Therefore, it is likely that VP MORs are involved in not only positive but also negative hedonic evaluation.
Collapse
MESH Headings
- Adjuvants, Immunologic/pharmacology
- Analgesics, Opioid/pharmacology
- Animals
- Avoidance Learning/drug effects
- Conditioning, Classical/drug effects
- Conditioning, Classical/physiology
- Conditioning, Psychological/drug effects
- Drinking/drug effects
- Drug Delivery Systems
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/pharmacology
- Globus Pallidus/drug effects
- Globus Pallidus/metabolism
- Lithium Chloride/pharmacology
- Male
- Microinjections
- Rats
- Rats, Wistar
- Receptors, Opioid, mu/genetics
- Receptors, Opioid, mu/metabolism
- Saccharin/administration & dosage
- Taste/drug effects
- Taste/physiology
- Taste Perception/drug effects
- Taste Perception/physiology
Collapse
Affiliation(s)
- Tadashi Inui
- Division of Behavioral Physiology, Department of Behavioral Sciences, Graduate School of Human Sciences, Osaka University, Suita, Osaka 565-0871 Japan.
| | - Tsuyoshi Shimura
- Division of Behavioral Physiology, Department of Behavioral Sciences, Graduate School of Human Sciences, Osaka University, Suita, Osaka 565-0871 Japan
| |
Collapse
|
11
|
Royet JP, Meunier D, Torquet N, Mouly AM, Jiang T. The Neural Bases of Disgust for Cheese: An fMRI Study. Front Hum Neurosci 2016; 10:511. [PMID: 27799903 PMCID: PMC5065955 DOI: 10.3389/fnhum.2016.00511] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 09/27/2016] [Indexed: 01/01/2023] Open
Abstract
The study of food aversion in humans by the induction of illness is ethically unthinkable, and it is difficult to propose a type of food that is disgusting for everybody. However, although cheese is considered edible by most people, it can also be perceived as particularly disgusting to some individuals. As such, the perception of cheese constitutes a good model to study the cerebral processes of food disgust and aversion. In this study, we show that a higher percentage of people are disgusted by cheese than by other types of food. Functional magnetic resonance imaging then reveals that the internal and external globus pallidus and the substantia nigra belonging to the basal ganglia are more activated in participants who dislike or diswant to eat cheese (Anti) than in other participants who like to eat cheese, as revealed following stimulation with cheese odors and pictures. We suggest that the aforementioned basal ganglia structures commonly involved in reward are also involved in the aversive motivated behaviors. Our results further show that the ventral pallidum, a core structure of the reward circuit, is deactivated in Anti subjects stimulated by cheese in the wanting task, highlighting the suppression of motivation-related activation in subjects disgusted by cheese.
Collapse
Affiliation(s)
- Jean-Pierre Royet
- Olfaction: From Coding to Memory Team, Lyon Neuroscience Research Center, CNRS UMR 5292 - INSERM U1028 - Université de Lyon 1 Lyon, France
| | - David Meunier
- Olfaction: From Coding to Memory Team, Lyon Neuroscience Research Center, CNRS UMR 5292 - INSERM U1028 - Université de Lyon 1 Lyon, France
| | - Nicolas Torquet
- Sorbonne Universités, Université Pierre et Marie Curie, Institut de Biologie Paris Seine, UM 119, CNRS, UMR 8246, Neuroscience Paris Seine Paris, France
| | - Anne-Marie Mouly
- Olfaction: From Coding to Memory Team, Lyon Neuroscience Research Center, CNRS UMR 5292 - INSERM U1028 - Université de Lyon 1 Lyon, France
| | - Tao Jiang
- Olfaction: From Coding to Memory Team, Lyon Neuroscience Research Center, CNRS UMR 5292 - INSERM U1028 - Université de Lyon 1 Lyon, France
| |
Collapse
|
12
|
Itoga CA, Berridge KC, Aldridge JW. Ventral pallidal coding of a learned taste aversion. Behav Brain Res 2015; 300:175-83. [PMID: 26615907 DOI: 10.1016/j.bbr.2015.11.024] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 11/04/2015] [Accepted: 11/19/2015] [Indexed: 12/30/2022]
Abstract
The hedonic value of a sweet food reward, or how much a taste is 'liked', has been suggested to be encoded by neuronal firing in the posterior ventral pallidum (VP). Hedonic impact can be altered by psychological manipulations, such as taste aversion conditioning, which can make an initially pleasant sweet taste become perceived as disgusting. Pairing nausea-inducing LiCl injection as a Pavlovian unconditioned stimulus (UCS) with a novel taste that is normally palatable as the predictive conditioned stimulus (CS+) suffices to induce a learned taste aversion that changes orofacial 'liking' responses to that sweet taste (e.g., lateral tongue protrusions) to 'disgust' reactions (e.g., gapes) in rats. We used two different sweet tastes of similar initial palatability (a sucrose solution and a polycose/saccharin solution, CS ± assignment was counterbalanced across groups) to produce a discriminative conditioned aversion. Only one of those tastes (arbitrarily assigned and designated as CS+) was associatively paired with LiCl injections as UCS to form a conditioned aversion. The other taste (CS-) was paired with mere vehicle injections to remain relatively palatable as a control sweet taste. We recorded the neural activity in VP in response to each taste, before and after aversion training. We found that the safe and positively hedonic taste always elicited excitatory increases in firing rate of VP neurons. By contrast, aversion learning reversed the VP response to the 'disgusting' CS+ taste from initial excitation into a conditioned decrease in neuronal firing rate after training. Such neuronal coding of hedonic impact by VP circuitry may contribute both to normal pleasure and disgust, and disruptions of VP coding could result in affective disorders, addictions and eating disorders.
Collapse
Affiliation(s)
- Christy A Itoga
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States.
| | - Kent C Berridge
- Psychology Department, University of Michigan, Ann Arbor, MI, United States
| | - J Wayne Aldridge
- Psychology Department, University of Michigan, Ann Arbor, MI, United States
| |
Collapse
|
13
|
Root DH, Melendez RI, Zaborszky L, Napier TC. The ventral pallidum: Subregion-specific functional anatomy and roles in motivated behaviors. Prog Neurobiol 2015; 130:29-70. [PMID: 25857550 PMCID: PMC4687907 DOI: 10.1016/j.pneurobio.2015.03.005] [Citation(s) in RCA: 220] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 03/19/2015] [Accepted: 03/29/2015] [Indexed: 12/17/2022]
Abstract
The ventral pallidum (VP) plays a critical role in the processing and execution of motivated behaviors. Yet this brain region is often overlooked in published discussions of the neurobiology of mental health (e.g., addiction, depression). This contributes to a gap in understanding the neurobiological mechanisms of psychiatric disorders. This review is presented to help bridge the gap by providing a resource for current knowledge of VP anatomy, projection patterns and subregional circuits, and how this organization relates to the function of VP neurons and ultimately behavior. For example, ventromedial (VPvm) and dorsolateral (VPdl) VP subregions receive projections from nucleus accumbens shell and core, respectively. Inhibitory GABAergic neurons of the VPvm project to mediodorsal thalamus, lateral hypothalamus, and ventral tegmental area, and this VP subregion helps discriminate the appropriate conditions to acquire natural rewards or drugs of abuse, consume preferred foods, and perform working memory tasks. GABAergic neurons of the VPdl project to subthalamic nucleus and substantia nigra pars reticulata, and this VP subregion is modulated by, and is necessary for, drug-seeking behavior. Additional circuits arise from nonGABAergic neuronal phenotypes that are likely to excite rather than inhibit their targets. These subregional and neuronal phenotypic circuits place the VP in a unique position to process motivationally relevant stimuli and coherent adaptive behaviors.
Collapse
Affiliation(s)
- David H Root
- Department of Psychology, Rutgers University, 152 Frelinghuysen Road, New Brunswick, NJ 08854, United States.
| | - Roberto I Melendez
- Department of Anatomy and Neurobiology, University of Puerto Rico School of Medicine, San Juan, PR 00936, United States.
| | - Laszlo Zaborszky
- Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, 197 University Avenue, Newark, NJ 07102, United States.
| | - T Celeste Napier
- Departments of Pharmacology and Psychiatry, Center for Compulsive Behavior and Addiction, Rush University Medical Center, Chicago, IL 60612, United States.
| |
Collapse
|
14
|
Systemic mechanism of taste, flavour and palatability in brain. Appl Biochem Biotechnol 2015; 175:3133-47. [PMID: 25733187 DOI: 10.1007/s12010-015-1488-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 01/09/2015] [Indexed: 01/10/2023]
Abstract
Taste is considered as one of the five traditional senses and has the ability to detect the flavour of food and certain minerals. Information of taste is transferred to the cortical gustatory area for identification and discrimination of taste quality. Animals have memory recognition power to maintain the familiar foods which are already encountered. Animal shows neophobic response when it encounters novel taste and shows no hesitation when the food is known to be safe. Palatability is the hedonic reward provided by foods and fluids. Palatability is closely related to neurochemicals, and this chemical influences the consumption of food and fluid. Even though, the food is palatable that can become aversive and avoided as a consequence of postingestional unpleasant experience such as malaise. This review presents the overall view on brain mechanisms of taste, flavour and palatability.
Collapse
|
15
|
Ho CY, Berridge KC. Excessive disgust caused by brain lesions or temporary inactivations: mapping hotspots of the nucleus accumbens and ventral pallidum. Eur J Neurosci 2014; 40:3556-72. [PMID: 25229197 PMCID: PMC4236281 DOI: 10.1111/ejn.12720] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 08/08/2014] [Accepted: 08/13/2014] [Indexed: 11/28/2022]
Abstract
Disgust is a prototypical type of negative affect. In animal models of excessive disgust, only a few brain sites are known in which localized dysfunction (lesions or neural inactivations) can induce intense 'disgust reactions' (e.g. gapes) to a normally pleasant sensation such as sweetness. Here, we aimed to map forebrain candidates more precisely, to identify where either local neuronal damage (excitotoxin lesions) or local pharmacological inactivation (muscimol/baclofen microinjections) caused rats to show excessive sensory disgust reactions to sucrose. Our study compared subregions of the nucleus accumbens shell, ventral pallidum, lateral hypothalamus, and adjacent extended amygdala. The results indicated that the posterior half of the ventral pallidum was the only forebrain site where intense sensory disgust gapes in response to sucrose were induced by both lesions and temporary inactivations (this site was previously identified as a hedonic hotspot for enhancements of sweetness 'liking'). By comparison, for the nucleus accumbens, temporary GABA inactivations in the caudal half of the medial shell also generated sensory disgust, but lesions never did at any site. Furthermore, even inactivations failed to induce disgust in the rostral half of the accumbens shell (which also contains a hedonic hotspot). In other structures, neither lesions nor inactivations induced disgust as long as the posterior ventral pallidum remained spared. We conclude that the posterior ventral pallidum is an especially crucial hotspot for producing excessive sensory disgust by local pharmacological/lesion dysfunction. By comparison, the nucleus accumbens appears to segregate sites for pharmacological disgust induction and hedonic enhancement into separate posterior and rostral halves of the medial shell.
Collapse
Affiliation(s)
- Chao-Yi Ho
- Department of Psychology, University of Michigan, Ann Arbor
| | | |
Collapse
|
16
|
Inui T, Shimura T. Delta-opioid receptor blockade in the ventral pallidum increases perceived palatability and consumption of saccharin solution in rats. Behav Brain Res 2014; 269:20-7. [DOI: 10.1016/j.bbr.2014.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 04/03/2014] [Accepted: 04/05/2014] [Indexed: 01/29/2023]
|
17
|
Activation of efferents from the basolateral amygdala during the retrieval of conditioned taste aversion. Neurobiol Learn Mem 2013; 106:210-20. [DOI: 10.1016/j.nlm.2013.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 08/12/2013] [Accepted: 09/02/2013] [Indexed: 11/18/2022]
|
18
|
Enhanced GABAergic tone in the ventral pallidum: memory of unpleasant experiences? Neuroscience 2011; 196:131-46. [DOI: 10.1016/j.neuroscience.2011.08.058] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 08/10/2011] [Accepted: 08/25/2011] [Indexed: 01/08/2023]
|
19
|
Yamamoto T, Ueji K. Brain mechanisms of flavor learning. Front Syst Neurosci 2011; 5:76. [PMID: 21922004 PMCID: PMC3166791 DOI: 10.3389/fnsys.2011.00076] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2011] [Accepted: 08/15/2011] [Indexed: 11/16/2022] Open
Abstract
Once the flavor of the ingested food (conditioned stimulus, CS) is associated with a preferable (e.g., good taste or nutritive satisfaction) or aversive (e.g., malaise with displeasure) signal (unconditioned stimulus, US), animals react to its subsequent exposure by increasing or decreasing ingestion to the food. These two types of association learning (preference learning vs. aversion learning) are known as classical conditioned reactions which are basic learning and memory phenomena, leading selection of food and proper food intake. Since the perception of flavor is generated by interaction of taste and odor during food intake, taste and/or odor are mainly associated with bodily signals in the flavor learning. After briefly reviewing flavor learning in general, brain mechanisms of conditioned taste aversion is described in more detail. The CS-US association leading to long-term potentiation in the amygdala, especially in its basolateral nucleus, is the basis of establishment of conditioned taste aversion. The novelty of the CS detected by the cortical gustatory area may be supportive in CS-US association. After the association, CS input is conveyed through the amygdala to different brain regions including the hippocampus for contextual fear formation, to the supramammillary and thalamic paraventricular nuclei for stressful anxiety or memory dependent fearful or stressful emotion, to the reward system to induce aversive expression to the CS, or hedonic shift from positive to negative, and to the CS-responsive neurons in the gustatory system to enhance the responsiveness to facilitate to detect the harmful stimulus.
Collapse
Affiliation(s)
- Takashi Yamamoto
- Department of Health and Nutrition, Faculty of Health Science, Kio UniversityNara, Japan
| | - Kayoko Ueji
- Department of Health and Nutrition, Faculty of Health Science, Kio UniversityNara, Japan
| |
Collapse
|
20
|
Inui T, Inui-Yamamoto C, Yoshioka Y, Ohzawa I, Shimura T. Activation of projective neurons from the nucleus accumbens to ventral pallidum by a learned aversive taste stimulus in rats: a manganese-enhanced magnetic resonance imaging study. Neuroscience 2011; 177:66-73. [DOI: 10.1016/j.neuroscience.2011.01.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 12/20/2010] [Accepted: 01/02/2011] [Indexed: 11/25/2022]
|
21
|
Inui-Yamamoto C, Yoshioka Y, Inui T, Sasaki KS, Ooi Y, Ueda K, Seiyama A, Ohzawa I. The brain mapping of the retrieval of conditioned taste aversion memory using manganese-enhanced magnetic resonance imaging in rats. Neuroscience 2010; 167:199-204. [PMID: 20167260 DOI: 10.1016/j.neuroscience.2010.02.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 02/09/2010] [Accepted: 02/11/2010] [Indexed: 10/19/2022]
Abstract
Manganese-enhanced MRI (MEMRI) is a newly developed noninvasive imaging technique of brain activities. The signal intensity of MEMRI reflects cumulative activities of the neurons. To validate the use of MEMRI technique to investigate the neural mechanisms of learning and memory, we tried to map brain areas involved in the retrieval of conditioned taste aversion (CTA) memory. CTAs were established to saccharin (conditioned stimulus: CS) by pairing its ingestion with an i.p. injection of LiCl (unconditioned stimulus: US). LiCl solutions (as a robust aversion chemical) of 0.15 M were injected i.p. 15 min after drinking the saccharine solution (CS). After the two times conditionings, these rats showed a robust aversion to the saccharine solution (CS). Rats of the control group were injected saline i.p. instead of LiCl solutions. The MRI signal intensities at the gustatory cortex (GC), the core subregion of the nucleus accumbens (NAcC), the shell subregion of the nucleus accumbens (NAcSh), the ventral pallidum (VP), the central nucleus of amygdala (CeA), the lateral hypothalamus (LH), and the basolateral nucleus of amygdala (BLA) of the conditioned group were higher than those of the control group. There were no significant differences between the conditioned and the control groups in the intensities for other regions, such as the striatum area, motor cortex, cingulate cortex, interstitial nucleus of the posterior limb of the anterior commissure and hippocampus. These indicate that the GC, NAcC, NAcSh, VP, CeA, LH and BLA have important roles in the memory retrieval of CTA.
Collapse
Affiliation(s)
- C Inui-Yamamoto
- High Performance Bioimaging Research Facility, Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan.
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Inui T, Yamamoto T, Shimura T. GABAergic transmission in the rat ventral pallidum mediates a saccharin palatability shift in conditioned taste aversion. Eur J Neurosci 2009; 30:110-5. [PMID: 19523097 DOI: 10.1111/j.1460-9568.2009.06800.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We previously found that the blockade of gamma-aminobutyric acid (GABA)(A) receptors in the ventral pallidum (VP) alters the taste palatability of a conditioned stimulus (CS) from aversive to ingestive after the establishment of conditioned taste aversion (CTA). Because these results suggest that GABAergic transmission in the VP mediates decreased palatability of the taste in CTA, the present study aimed to examine the effects of taste stimulation on the extracellular release of GABA in the VP using in vivo microdialysis. Initially, rats received a paired presentation of 5 mm saccharin or 0.3 mm quinine solution with an intraperitoneal injection of 0.15 m lithium chloride (S-CTA and Q-CTA groups) or saline (S-control and Q-control groups). After conditioning, microdialysis was carried out before, during and after the presentation of the CS via an intra-oral cannula. We measured the latency of the first aversive orofacial responses to the CS as behavioral indices. In the S-CTA group, which rapidly rejected the CS (within 100 s), the GABA efflux was significantly increased (147%) and was maintained for 2 h. On the other hand, the S-control group expressed no aversive responses and showed no significant alterations in GABA efflux. Although the Q-CTA group immediately expressed aversive responses to the CS (within 30 s), GABA release was not changed by presentation of the CS, which was similar in the Q-control group. These findings suggest that the palatability shift from ingestive to aversive in conditioned aversion to saccharin, but not quinine, is mediated by the change in GABAergic transmission in the VP.
Collapse
Affiliation(s)
- Tadashi Inui
- Division of Behavioral Physiology, Department of Behavioral Sciences, Graduate School of Human Sciences, Osaka University, 1-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | | | | |
Collapse
|
23
|
Sevelinges Y, Desgranges B, Ferreira G. The basolateral amygdala is necessary for the encoding and the expression of odor memory. Learn Mem 2009; 16:235-42. [PMID: 19304894 DOI: 10.1101/lm.1247609] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Conditioned odor avoidance (COA) results from the association between a novel odor and a delayed visceral illness. The present experiments investigated the role of the basolateral amygdala (BLA) in acquisition and retrieval of COA memory. To address this, we used the GABA(A) agonist muscimol to temporarily inactivate the BLA during COA acquisition or expression. BLA inactivation before odor-malaise pairing greatly impaired COA tested 3 d later. In contrast, muscimol microinfusion between odor and malaise spared retention. Moreover, inactivation of the BLA before pre-exposure to the odor prevented latent inhibition of COA. This suggests that neural activity in the BLA is essential for the formation of odor representation. BLA inactivation before the retrieval test also blocked COA memory expression when performed either 3 d (recent memory) or 28 d (remote memory) after acquisition. This effect was transitory as muscimol-treated animals were not different from controls during the subsequent extinction tests. Moreover, muscimol infusion in the BLA neither affected olfactory perception nor avoidance behavior, and it did not induce a state-dependent learning. Altogether, these findings suggest that neural activity in the BLA is required for the encoding and the retrieval of odor memory. Moreover, the BLA seems to play a permanent role in the expression of COA.
Collapse
Affiliation(s)
- Yannick Sevelinges
- Laboratoire de Comportement, Neurobiologie et Adaptation, CNRS UMR 6175, INRA UMR 85, Université Tours, Nouzilly, France
| | | | | |
Collapse
|
24
|
Smith KS, Tindell AJ, Aldridge JW, Berridge KC. Ventral pallidum roles in reward and motivation. Behav Brain Res 2008; 196:155-67. [PMID: 18955088 DOI: 10.1016/j.bbr.2008.09.038] [Citation(s) in RCA: 377] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Accepted: 09/22/2008] [Indexed: 10/21/2022]
Abstract
In recent years the ventral pallidum has become a focus of great research interest as a mechanism of reward and incentive motivation. As a major output for limbic signals, the ventral pallidum was once associated primarily with motor functions rather than regarded as a reward structure in its own right. However, ample evidence now suggests that ventral pallidum function is a major mechanism of reward in the brain. We review data indicating that (1) an intact ventral pallidum is necessary for normal reward and motivation, (2) stimulated activation of ventral pallidum is sufficient to cause reward and motivation enhancements, and (3) activation patterns in ventral pallidum neurons specifically encode reward and motivation signals via phasic bursts of excitation to incentive and hedonic stimuli. We conclude that the ventral pallidum may serve as an important 'limbic final common pathway' for mesocorticolimbic processing of many rewards.
Collapse
Affiliation(s)
- Kyle S Smith
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| | | | | | | |
Collapse
|
25
|
Central mechanisms of taste: Cognition, emotion and taste-elicited behaviors. JAPANESE DENTAL SCIENCE REVIEW 2008. [DOI: 10.1016/j.jdsr.2008.07.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
|
26
|
Abstract
Taste is unique among sensory systems in its innate association with mechanisms of reward and aversion in addition to its recognition of quality, e.g., sucrose is sweet and preferable, and quinine is bitter and aversive. Taste information is sent to the reward system and feeding center via the prefrontal cortices such as the mediodorsal and ventrolateral prefrontal cortices in rodents and the orbitofrontal cortex in primates. The amygdala, which receives taste inputs, also influences reward and feeding. In terms of neuroactive substances, palatability is closely related to benzodiazepine derivatives and beta-endorphin, both of which facilitate consumption of food and fluid. The reward system contains the ventral tegmental area, nucleus accumbens and ventral pallidum and finally sends information to the lateral hypothalamic area, the feeding center. The dopaminergic system originating from the ventral tegmental area mediates the motivation to consume palatable food. The actual ingestive behavior is promoted by the orexigenic neuropeptides from the hypothalamus. Even palatable food can become aversive and avoided as a consequence of a postingestional unpleasant experience such as malaise. The neural mechanisms of this conditioned taste aversion will also be elucidated.
Collapse
Affiliation(s)
- T Yamamoto
- Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan.
| |
Collapse
|