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Mendes NF, Mariotti FFN, de Andrade JS, de Barros Viana M, Céspedes IC, Nagaoka MR, Le Sueur-Maluf L. Lactulose decreases neuronal activation and attenuates motor behavioral deficits in hyperammonemic rats. Metab Brain Dis 2017; 32:2073-2083. [PMID: 28875419 DOI: 10.1007/s11011-017-0098-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 08/16/2017] [Indexed: 12/14/2022]
Abstract
Lactulose is a nonabsorbable disaccharide commonly used in clinical practice to treat hepatic encephalopathy. However, its effects on neuropsychiatric disorders and motor behavior have not been fully elucidated. Male Wistar rats were bile-duct ligated, and 3 weeks after surgery, treated with lactulose administrated by gavage (1.43 or 3.57 g/kg), once a day for seven days. Plasma levels of ammonia, aspartate aminotransferase, total bilirubin, and creatinine were quantified and histopathological analysis of the livers was performed. Locomotor activity measurements were performed in an open field. The expression of water channel aquaporin-4 was investigated and the analysis of Fos protein immunoreactivity was used to evaluate the pattern of neural activation in brain areas related to motor behavior. Bile-duct ligated rats showed hyperammonemia, loss of liver integrity and function, impaired locomotor activity, reduced aquaporin-4 protein expression, and neuronal hyperactivity. Lactulose treatment was able to reduce ammonia plasma levels, despite not having an effect on biochemical parameters of liver function, such as aspartate aminotransferase activity and total bilirubin levels, or on the cirrhotic hepatic architecture. Lactulose was also able to reduce the locomotor activity impairments and to mitigate or reverse most changes in neuronal activation. Lactulose had no effect on reduced aquaporin-4 protein expression. Our findings confirm the effectiveness of lactulose in reducing hyperammonemia and neuronal hyperactivity in brain areas related to motor behavior, reinforcing the importance of its clinical use in the treatment of the symptoms of cirrhosis-associated encephalopathy.
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Affiliation(s)
- Natália Ferreira Mendes
- Departmento de Biociências, Universidade Federal de São Paulo, UNIFESP, 133/136 - Vila Mathias, Santos/SP, 11015-020, Brazil
- Laboratório de Sinalização Celular, Universidade Estadual de Campinas, UNICAMP, Campinas/SP, 13083-864, Brazil
| | - Flora França Nogueira Mariotti
- Departmento de Biociências, Universidade Federal de São Paulo, UNIFESP, 133/136 - Vila Mathias, Santos/SP, 11015-020, Brazil
| | - José Simões de Andrade
- Departmento de Biociências, Universidade Federal de São Paulo, UNIFESP, 133/136 - Vila Mathias, Santos/SP, 11015-020, Brazil
| | - Milena de Barros Viana
- Departmento de Biociências, Universidade Federal de São Paulo, UNIFESP, 133/136 - Vila Mathias, Santos/SP, 11015-020, Brazil
| | - Isabel Cristina Céspedes
- Departmento de Biociências, Universidade Federal de São Paulo, UNIFESP, 133/136 - Vila Mathias, Santos/SP, 11015-020, Brazil
- Departamento de Morfologia e Genética, Universidade Federal de São Paulo, UNIFESP, 11015-020, São Paulo/SP, 04023-900, Brazil
| | - Márcia Regina Nagaoka
- Departmento de Biociências, Universidade Federal de São Paulo, UNIFESP, 133/136 - Vila Mathias, Santos/SP, 11015-020, Brazil
| | - Luciana Le Sueur-Maluf
- Departmento de Biociências, Universidade Federal de São Paulo, UNIFESP, 133/136 - Vila Mathias, Santos/SP, 11015-020, Brazil.
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Royes LFF, Gabbi P, Ribeiro LR, Della-Pace ID, Rodrigues FS, de Oliveira Ferreira AP, da Silveira Junior MEP, da Silva LRH, Grisólia ABA, Braga DV, Dobrachinski F, da Silva AMHO, Soares FAA, Marchesan S, Furian AF, Oliveira MS, Fighera MR. A neuronal disruption in redox homeostasis elicited by ammonia alters the glycine/glutamate (GABA) cycle and contributes to MMA-induced excitability. Amino Acids 2016; 48:1373-89. [DOI: 10.1007/s00726-015-2164-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 12/24/2015] [Indexed: 12/28/2022]
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Chepkova AN, Selbach O, Haas HL, Sergeeva OA. Ammonia-induced deficit in corticostriatal long-term depression and its amelioration by zaprinast. J Neurochem 2012; 122:545-56. [PMID: 22639911 DOI: 10.1111/j.1471-4159.2012.07806.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hyperammonemia is a major pathophysiological factor in encephalopathies associated with acute and chronic liver failure. On mouse brain slice preparations, we analyzed the effects of ammonia on the characteristics of corticostriatal long-term depression (LTD) induced by electrical stimulation of cortical input or pharmacological activation of metabotropic glutamate receptors. Long exposure of neostriatal slices to ammonium chloride impaired the induction and/or expression of all studied forms of LTD. This impairment was reversed by the phosphodiesterase inhibitor zaprinast implying lowered cGMP signaling in LTD suppression. Polyphenols from green tea rescued short-term corticostriatal plasticity, but failed to prevent the ammonia-induced deficit of LTD. Zaprinast counteracts the ammonia-induced impairment of long-term corticostriatal plasticity and may thus improve fine motor skills and procedural learning in hepatic encephalopathy.
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Affiliation(s)
- Aisa N Chepkova
- Department of Neurophysiology, Medical Faculty, Heinrich-Heine-University, Dusseldorf, Germany
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Méndez M, Méndez-López M, López L, Aller MA, Arias J, Arias JL. Portosystemic hepatic encephalopathy model shows reversal learning impairment and dysfunction of neural activity in the prefrontal cortex and regions involved in motivated behavior. J Clin Neurosci 2011; 18:690-4. [PMID: 21371891 DOI: 10.1016/j.jocn.2010.09.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Revised: 09/15/2010] [Accepted: 09/22/2010] [Indexed: 11/16/2022]
Abstract
Hepatic encephalopathy (HE) is a neurological complication that affects attention and memory. Experimental animal models have been used to study HE, the most frequent being the portacaval shunt (PCS). In order to investigate learning impairment and brain functional alterations in this model, we assessed reversal learning and neural metabolic activity in a PCS rat model. PCS and sham-operated rats were tested for reversal learning in the Morris water maze. Brains were then processed for cytochrome oxidase (CO) histochemistry. The PCS group had reversal learning impairment and a reduction in CO activity in the prefrontal cortex, ventral tegmental area and accumbens shell nucleus. These results suggest that this model of portosystemic HE shows learning impairments that could be linked to dysfunction in neural activity in the prefrontal cortex and regions involved in motivated behavior.
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Affiliation(s)
- M Méndez
- Laboratorio de Neurociencias, Departamento de Psicología, Universidad de Oviedo, Plaza Feijoo s/n. 33003, Oviedo, Spain.
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Effect of the class I metabotropic glutamate receptor antagonist AIDA on certain behaviours in rats with experimental chronic hyperammonemia. Adv Med Sci 2010; 54:269-76. [PMID: 19875354 DOI: 10.2478/v10039-009-0037-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE This study examines possible interactions between behavioral effects and mGluR1 (class I metabotropic glutamate receptor) by injecting AIDA [(RS)-1-aminoindan-1,5-dicarboxylic acid] in rats with experimental chronic hyperammonemia (chHA). MATERIAL/METHODS The effects of mGluR1 antagonist on some behaviors were tested in control groups of rats and in rats with chHA. Experimental chHA was induced by intraperitoneal injection of ammonium acetate (12 mmol/kg) for five consecutive days. We used the following behavioural tests: the open field test, the passive avoidance test and the elevated "plus" maze. RESULTS In control rats AIDA administered intracerebroventricularly (i.c.v.) at the dose 100 nmol decreased the number of crossings and bar approaches in the open field test and impaired acquisition and recall in the passive avoidance situation. ChHA significantly inhibited locomotor and exploratory activity and profoundly impaired acquisition and recall processes in the passive avoidance test and significantly increased acute stress responses. AIDA increased locomotor activity in chHA rats (especially number of crossed fields and rearings) and produced anxiety enhancement in rats with chHA. AIDA used in rats with chHA significantly improved acquisition and retrieval processes. CONCLUSIONS The obtained results suggest that AIDA, the antagonist of mGluR1, had beneficial effects on learning and memory in rats with experimental chronic hyperammonemia.
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Méndez M, Méndez-López M, López L, Aller MA, Arias J, Arias JL. Working memory impairment and reduced hippocampal and prefrontal cortex c-Fos expression in a rat model of cirrhosis. Physiol Behav 2008; 95:302-7. [PMID: 18634813 DOI: 10.1016/j.physbeh.2008.06.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Revised: 06/05/2008] [Accepted: 06/23/2008] [Indexed: 10/21/2022]
Abstract
Hepatic encephalopathy (HE) is a frequent neurological complication observed in patients with liver malfunction. Previous studies have shown memory impairment in these patients. In order to investigate brain substrates of spatial working memory impairment in chronic HE, neuronal expression of c-Fos protein was studied in an experimental model of cirrhosis. Control and cirrhotic rats were trained on a spatial working memory task in the Morris water maze (MWM). Differences between groups were found in the working memory task. Cirrhotic rats were unable to locate the platform in the retention trial. Neuronal activation, measured by c-Fos protein, was compared between groups. No differences were found in c-Fos expression of control and cirrhotic rats that were not tested in the MWM. Working memory task produced increase in c-Fos positive cells in dorsal hippocampus, CA1 and CA3, and prefrontal cortex in control group compared to thioacetamide group or naïve, which only swam in the maze during a similar time. These findings suggest that cirrhotic rats show spatial working memory impairment that could be linked to dysfunction in neuronal activity in prefrontal cortex and hippocampus.
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Affiliation(s)
- Marta Méndez
- Laboratorio de Neurociencias, Departamento de Psicología, Universidad de Oviedo, Plaza Feijoo s/n, 33003 Oviedo, Spain
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Mechanistic relationships between Drosophila fragile X mental retardation protein and metabotropic glutamate receptor A signaling. Mol Cell Neurosci 2008; 37:747-60. [PMID: 18280750 DOI: 10.1016/j.mcn.2008.01.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2007] [Revised: 12/20/2007] [Accepted: 01/03/2008] [Indexed: 11/23/2022] Open
Abstract
Fragile X syndrome is caused by loss of the FMRP translational regulator. A current hypothesis proposes that FMRP functions downstream of mGluR signaling to regulate synaptic connections. Using the Drosophila disease model, we test relationships between dFMRP and the sole Drosophila mGluR (DmGluRA) by assaying protein expression, behavior and neuron structure in brain and NMJ; in single mutants, double mutants and with an mGluR antagonist. At the protein level, dFMRP is upregulated in dmGluRA mutants, and DmGluRA is upregulated in dfmr1 mutants, demonstrating mutual negative feedback. Null dmGluRA mutants display defects in coordinated movement behavior, which are rescued by removing dFMRP expression. Null dfmr1 mutants display increased NMJ presynaptic structural complexity and elevated presynaptic vesicle pools, which are rescued by blocking mGluR signaling. Null dfmr1 brain neurons similarly display increased presynaptic architectural complexity, which is rescued by blocking mGluR signaling. These data show that DmGluRA and dFMRP convergently regulate presynaptic properties.
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