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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.
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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.
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Kimura A, Sugimoto T, Niida S, Toba K, Sakurai T. Association Between Appetite and Sarcopenia in Patients With Mild Cognitive Impairment and Early-Stage Alzheimer's Disease: A Case-Control Study. Front Nutr 2019; 5:128. [PMID: 30619874 PMCID: PMC6305366 DOI: 10.3389/fnut.2018.00128] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Accepted: 12/04/2018] [Indexed: 01/07/2023] Open
Abstract
Background: Sarcopenia is frequently seen in patients with mild cognitive impairment (MCI) and early-stage Alzheimer's disease (AD). While appetite loss and physical inactivity, which are also frequently seen in dementia, appear to contribute to sarcopenia, to date, no study has investigated this association. Objective: The aim of this study was to examine factors associated with sarcopenia, including appetite and physical activity, in patients with MCI and early-stage AD. Methods: The study subjects comprised 205 outpatients (MCI, n = 151; early-stage AD, n = 54) who were being treated at the Memory Clinic, National Center for Geriatrics, and Gerontology and had a Mini-Mental State Examination (MMSE) score of 21 or higher. All subjects were assessed for appetite by using the Council on Nutrition Appetite Questionnaire (CNAQ). Confounding variables assessed included physical activity, activities of daily living, mood, body mass index (BMI), nutritional status, and medications. Sarcopenia was defined as low muscle mass and low handgrip strength or slow gait speed. Multivariate logistic regression analyses were performed with adjustment for age, gender, education, and confounding variables to examine the association of sarcopenia with physical activity and appetite. Furthermore, sub-analyses were also conducted to clarify the relationship between CNAQ sub-items and sarcopenia. Results: The prevalence of sarcopenia among the subjects was 14.6% (n = 30). Patients with sarcopenia had lower CNAQ scores (those with sarcopenia, 26.7 ± 3.5; those without, 29.1 ± 2.5). Multivariate analysis showed that BMI (odds ratio [OR], 0.675; 95% confidence interval [CI], 0.534-0.853), polypharmacy (OR, 4.489; 95% CI, 1.315-15.320), and CNAQ (OR, 0.774; 95% CI, 0.630-0.952) were shown to be associated with sarcopenia. Physical activity was not associated with sarcopenia. Of the sub-items of the CNAQ, appetite (OR, 0.353; 95% CI, 0.155-0.805), feeling full (OR, 0.320; 95% CI = 0.135-0.761), and food tastes compared to when younger (OR, 0.299; 95% CI, 0.109-0.818) were shown to be associated with sarcopenia. Conclusions: These results suggest that appetite could be a modifiable risk factor for sarcopenia in patients with MCI and early-stage AD. A comprehensive approach to improving appetite may prove effective in preventing sarcopenia.
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Affiliation(s)
- Ai Kimura
- Center for Comprehensive Care and Research on Memory Disorders, National Center for Geriatrics and Gerontology, Obu, Japan.,Medical Genome Center, National Center for Geriatrics and Gerontology, Obu, Japan.,Department of Cognitive and Behavioral Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Taiki Sugimoto
- Center for Comprehensive Care and Research on Memory Disorders, National Center for Geriatrics and Gerontology, Obu, Japan.,Medical Genome Center, National Center for Geriatrics and Gerontology, Obu, Japan.,Department of Community Health Sciences, Graduate School of Health Sciences, Kobe University, Kobe, Japan.,Japan Society for the Promotion of Science, Tokyo, Japan
| | - Shumpei Niida
- Medical Genome Center, National Center for Geriatrics and Gerontology, Obu, Japan
| | - Kenji Toba
- Center for Comprehensive Care and Research on Memory Disorders, National Center for Geriatrics and Gerontology, Obu, Japan
| | - Takashi Sakurai
- Center for Comprehensive Care and Research on Memory Disorders, National Center for Geriatrics and Gerontology, Obu, Japan.,Department of Cognitive and Behavioral Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
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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.
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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.
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Selleck RA, Giacomini J, Buchholtz BD, Lake C, Sadeghian K, Baldo BA. Modulation of appetitive motivation by prefrontal cortical mu-opioid receptors is dependent upon local dopamine D1 receptor signaling. Neuropharmacology 2018; 140:302-309. [PMID: 30086291 DOI: 10.1016/j.neuropharm.2018.07.033] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/25/2018] [Accepted: 07/26/2018] [Indexed: 10/28/2022]
Abstract
Opioid neurotransmission has been implicated in psychiatric disorders featuring impaired control over appetitive motivation, such as addiction and binge-eating disorder. We have previously shown that infusions of the μ-opioid receptor (μOR) agonist DAMGO into the ventromedial prefrontal cortex (vmPFC) induced hyperphagia, increased motor activity, and augmented sucrose-reinforced responding in the task progressive ratio (PR) task, which assesses the motivational value of an incentive. These effects were not reproduced by intra-PFC infusion of a variety of dopamine (DA) agonists and antagonists, suggesting that manipulation of intra-PFC DA systems alone is not sufficient to reproduce μOR-like effects. Nevertheless, this does not rule out interactions between PFC DA and μ-opioid systems. Here we used intra-vmPFC drug cocktails containing DAMGO and SCH 23390 (a DA D1 receptor antagonist) to determine whether increases in appetitive motivation and motor activity elicited by intra-vmPFC μOR stimulation require intact signaling through vmPFC D1 receptors. Blockade of D1 receptors with SCH 23390 attenuated the enhancement of PR breakpoint, and increases in exploratory-like behavior and feeding initiation elicited by intra-vmPFC μOR stimulation. These results establish that intra-vmPFC D1 signaling is required for the expression of behavioral effects evoked by μOR stimulation within the PFC, and further suggest that D1 tone plays an enabling or permissive role in the expression of μOR -elicited effects. Simultaneous targeting of both μ-opioid and D1 systems may represent a more efficacious treatment strategy (compared to μOR blockade alone) for psychiatric disorders characterized by dysregulated appetitive motivation.
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Affiliation(s)
- Ryan A Selleck
- Dept. Cellular & Molecular Pharmacology, Rosalind Franklin, Univ.of Medicine & Science, USA
| | - Juliana Giacomini
- Physiology Graduate Training Program, Univ. Wisconsin-Madison, School of Medicine &Public Health, USA
| | | | - Curtis Lake
- College of Agricultural & Life Sciences, Univ. Wisconsin-Madison, USA
| | - Ken Sadeghian
- Dept. Psychiatry, Univ. Wisconsin-Madison, School of Medicine & Public Health, USA
| | - Brian A Baldo
- Dept. Psychiatry, Univ. Wisconsin-Madison, School of Medicine & Public Health, USA.
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Caynas-Rojas S, Rodríguez-García G, Delint-Ramírez I, Miranda MI. Differential function of medial prefrontal cortex catecholaminergic receptors after long-term sugar consumption. Behav Brain Res 2018; 356:495-503. [PMID: 29920309 DOI: 10.1016/j.bbr.2018.06.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 06/07/2018] [Accepted: 06/08/2018] [Indexed: 12/18/2022]
Abstract
The medial prefrontal cortex (mPFC) has reciprocal projections with many cerebral structures that are crucial in the control of food ingestion behavior and reward processing; Thus the mPFC has an important function in taste memory recognition. Previous results indicate that long-term consumption of sugar produces changes in appetitive re-learning and suggest that this could trigger an escalating consumption due to the inability to learn new negative consequences related to the same taste. Further evidence suggests that general identity reward value could be encoded in the mPFC. Therefore, the purpose of this study was to evaluate in rats whether after 21 days of sugar consumption the increase in sweet taste preference and latent inhibition of conditioned taste aversion (CTA) were affected differentially by pharmacological activation or blockage of dopaminergic and β-adrenergic receptors, in the mPFC, during CTA acquisition. Results showed that after long-term sugar exposure, mPFC activation of β-adrenergic receptors with clenbuterol delayed aversive memory extinction, but the blockade with propranolol or activation of dopaminergic receptors with apomorphine increased CTA latent inhibition and accelerated aversive memory extinction only after acute sugar exposure. Only dopaminergic blockade with haloperidol prevented sweet taste preference expression after long-term sugar consumption, increased CTA latent inhibition and accelerated extinction after acute sugar exposure. Taken together, the present data provide evidence that catecholaminergic receptors in the mPFC after prolonged sugar consumption underwent functional changes related to re-learning and new aversive taste learning.
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Affiliation(s)
- Seraid Caynas-Rojas
- Departamento de Neurobiología Conductual y Cognitiva, Instituto de Neurobiología, UNAM, Campus Juriquilla, Querétaro, 76230, Mexico
| | - Gabriela Rodríguez-García
- Departamento de Neurobiología Conductual y Cognitiva, Instituto de Neurobiología, UNAM, Campus Juriquilla, Querétaro, 76230, Mexico
| | - Ilse Delint-Ramírez
- Departamento de Farmacología y Toxicología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey, 64460, Mexico
| | - María Isabel Miranda
- Departamento de Neurobiología Conductual y Cognitiva, Instituto de Neurobiología, UNAM, Campus Juriquilla, Querétaro, 76230, Mexico.
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Gálosi R, Petykó Z, Kállai V, Tóth A, Ollmann T, Péczely L, Kovács A, Berta B, Lénárd L. Destruction of noradrenergic terminals increases dopamine concentration and reduces dopamine metabolism in the medial prefrontal cortex. Behav Brain Res 2018; 344:57-64. [PMID: 29454007 DOI: 10.1016/j.bbr.2018.02.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 02/13/2018] [Accepted: 02/13/2018] [Indexed: 01/01/2023]
Abstract
Effects of destroyed noradrenergic (NE) innervation in the medial prefrontal cortex (mPFC) were examined on dopamine (DA) content and metabolism. Six-hydroxy-DOPA (6-OHDOPA) or 6-hydroxy-dopamine (6-OHDA) in combination with a potent DA reuptake inhibitor GBR 12935 or 6-OHDA were injected bilaterally into the mPFC in separate groups of animals. In addition, GBR 12935 or vehicle was injected into the mPFC in two other groups of animals as control experiments. NE and DA concentrations from postmortem tissue of the mPFC were measured using HPLC with electrochemical detection. In addition, extracellular NE, DA and DOPAC levels were determined using in vivo microdialysis after the 6-OHDA lesion in combination with GBR 12935 pretreatment in the mPFC. Using reverse microdialysis of alpha-2-adrenoreceptor antagonist yohimbine, we tested the remaining activity of NE innervation and the extracellular concentration of DA and DOPAC. NE and DA concentrations from postmortem tissue of the mPFC showed that 6-OHDOPA lesion reduced NE concentration to 76%, which was a non-significant alteration, however it enhanced significantly DA concentration to 186% compared to vehicle. After 6-OHDA lesion with GBR 12935 pretreatment, concentration of NE significantly decreased to 51% and DA level increased to 180%. 6-OHDA lesion without GBR 12635 pretreatment decreased NE concentration to 23% and DA concentration to 67%. In the microdialysis experiment, after 6-OHDA lesion with GBR 12935 pretreatment, extracellular NE levels were not detectable, whereas extracellular DA levels were increased and DOPAC levels were decreased compared to controls. Reverse microdialysis of yohimbine demonstrated that the residual NE innervation was able to increase NE level and DA levels, but DOPAC concentration remained low after lesion of the NE terminals. These findings suggest that the damage of NE innervation in the mPFC may alter extracellular DA level due to a reduced DA clearance.
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Affiliation(s)
- Rita Gálosi
- Institute of Physiology, University of Pécs Medical School, Pécs, Hungary.
| | - Zoltán Petykó
- Institute of Physiology, University of Pécs Medical School, Pécs, Hungary; Molecular Neuroendocrinology Research Group, University of Pécs, Szentágothai Research Center, Pécs, Hungary
| | - Veronika Kállai
- Institute of Physiology, University of Pécs Medical School, Pécs, Hungary
| | - Attila Tóth
- Institute of Physiology, University of Pécs Medical School, Pécs, Hungary
| | - Tamás Ollmann
- Institute of Physiology, University of Pécs Medical School, Pécs, Hungary
| | - László Péczely
- Institute of Physiology, University of Pécs Medical School, Pécs, Hungary
| | - Anita Kovács
- Institute of Physiology, University of Pécs Medical School, Pécs, Hungary
| | - Beáta Berta
- Institute of Physiology, University of Pécs Medical School, Pécs, Hungary
| | - László Lénárd
- Institute of Physiology, University of Pécs Medical School, Pécs, Hungary; Molecular Neuroendocrinology Research Group, University of Pécs, Szentágothai Research Center, Pécs, Hungary
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Szabó I, Hormay E, Csetényi B, Nagy B, Lénárd L, Karádi Z. Multiple functional attributes of glucose-monitoring neurons in the medial orbitofrontal (ventrolateral prefrontal) cortex. Neurosci Biobehav Rev 2018; 85:44-53. [DOI: 10.1016/j.neubiorev.2017.04.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 04/11/2017] [Accepted: 04/21/2017] [Indexed: 11/28/2022]
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8
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Gálosi R, Szalay C, Aradi M, Perlaki G, Pál J, Steier R, Lénárd L, Karádi Z. Identifying non-toxic doses of manganese for manganese-enhanced magnetic resonance imaging to map brain areas activated by operant behavior in trained rats. Magn Reson Imaging 2016; 37:122-133. [PMID: 27889621 DOI: 10.1016/j.mri.2016.11.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 11/21/2016] [Accepted: 11/22/2016] [Indexed: 12/13/2022]
Abstract
Manganese-enhanced magnetic resonance imaging (MEMRI) offers unique advantages such as studying brain activation in freely moving rats, but its usefulness has not been previously evaluated during operant behavior training. Manganese in a form of MnCl2, at a dose of 20mg/kg, was intraperitoneally infused. The administration was repeated and separated by 24h to reach the dose of 40mg/kg or 60mg/kg, respectively. Hepatotoxicity of the MnCl2 was evaluated by determining serum aspartate aminotransferase, alanine aminotransferase, total bilirubin, albumin and protein levels. Neurological examination was also carried out. The animals were tested in visual cue discriminated operant task. Imaging was performed using a 3T clinical MR scanner. T1 values were determined before and after MnCl2 administrations. Manganese-enhanced images of each animal were subtracted from their baseline images to calculate decrease in the T1 value (ΔT1) voxel by voxel. The subtracted T1 maps of trained animals performing visual cue discriminated operant task, and those of naive rats were compared. The dose of 60mg/kg MnCl2 showed hepatotoxic effect, but even these animals did not exhibit neurological symptoms. The dose of 20 and 40mg/kg MnCl2 increased the number of omissions and did not affect the accuracy of performing the visual cue discriminated operant task. Using the accumulated dose of 40mg/kg, voxels with a significant enhanced ΔT1 value were detected in the following brain areas of the visual cue discriminated operant behavior performed animals compared to those in the controls: the visual, somatosensory, motor and premotor cortices, the insula, cingulate, ectorhinal, entorhinal, perirhinal and piriform cortices, hippocampus, amygdala with amygdalohippocampal areas, dorsal striatum, nucleus accumbens core, substantia nigra, and retrorubral field. In conclusion, the MEMRI proved to be a reliable method to accomplish brain activity mapping in correlation with the operant behavior of freely moving rodents.
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Affiliation(s)
- Rita Gálosi
- Institute of Physiology, Medical School of University of Pécs, Pécs, Hungary.
| | - Csaba Szalay
- Institute of Physiology, Medical School of University of Pécs, Pécs, Hungary.
| | | | - Gábor Perlaki
- Neurosurgery Clinic, Medical School of University of Pécs, Pécs, Hungary; Pécs Diagnostic Center, Pécs, Hungary
| | - József Pál
- Neurosurgery Clinic, Medical School of University of Pécs, Pécs, Hungary
| | - Roy Steier
- Neurosurgery Clinic, Medical School of University of Pécs, Pécs, Hungary.
| | - László Lénárd
- Institute of Physiology, Medical School of University of Pécs, Pécs, Hungary; Molecular Neuroendocrinology and Neurophysiology Research Group, Szentágothai Research Center, University of Pécs, Pécs, Hungary
| | - Zoltán Karádi
- Institute of Physiology, Medical School of University of Pécs, Pécs, Hungary; Molecular Neuroendocrinology and Neurophysiology Research Group, Szentágothai Research Center, University of Pécs, Pécs, Hungary
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