Cytochrome Oxidase Activity of the Suprachiasmatic Nucleus and Pineal Gland in Rats with Portacaval Shunt

López, Laudino; González-Pardo, Héctor; Cimadevilla, José Manuel; Cavas, M.; Aller, María-Ángeles; Árias, Jaime; Árias, Jorge L.

doi:10.1006/exnr.2001.7840

Cited by 9 publications

(4 citation statements)

References 75 publications

(84 reference statements)

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“…17 Other studies have reported that brain oxidative metabolism impairment is associated with behavioral alterations in PCS rats. 23,24 In the present work, we showed that CO activity was lower in the medial prefrontal cortex, accumbens region and ventral tegmental area in the PCS model compared with the sham animals after performing the spatial reversal task in the MWM. This might have been due to inefficient acquisition of the reversal task by the PCS group.…”

Section: Discussionmentioning

confidence: 83%

Portosystemic hepatic encephalopathy model shows reversal learning impairment and dysfunction of neural activity in the prefrontal cortex and regions involved in motivated behavior

Méndez¹,

Méndez-López²,

López³

et al. 2011

Journal of Clinical Neuroscience

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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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Section: Discussionmentioning

confidence: 83%

Portosystemic hepatic encephalopathy model shows reversal learning impairment and dysfunction of neural activity in the prefrontal cortex and regions involved in motivated behavior

Méndez¹,

Méndez-López²,

López³

et al. 2011

Journal of Clinical Neuroscience

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“…Escobar et al (2002) showed that rats with dysfunctional liver resulting from chronic treatment with CCl 4 show metabolic derangement of the clock mechanisms of the suprachiasmatic nucleus. Altered circadian rhythms of locomotor activity and of melatonin levels have been reported in rats with portacaval shunts, an animal model of hepatic encephalopathy (Zee et al,1991; Coy et al,1992) that also shows altered oxidative metabolism in the suprachiasmatic nucleus (López et al,2002,2003).…”

mentioning

confidence: 99%

Chronic hyperammonemia alters the circadian rhythms of corticosteroid hormone levels and of motor activity in rats

Ahabrach

Piedrafita

Ayad

et al. 2009

J of Neuroscience Research

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Patients with liver cirrhosis may present hepatic encephalopathy with a wide range of neurological disturbances and alterations in sleep quality and in the sleep-wake circadian rhythm. Hyperammonemia is a main contributor to the neurological alterations in hepatic encephalopathy. We have assessed, in an animal model of chronic hyperammonemia without liver failure, the effects of hyperammonemia per se on the circadian rhythms of motor activity, temperature, and plasma levels of adrenal corticosteroid hormones. Chronic hyperammonemia alters the circadian rhythms of locomotor activity and of cortisol and corticosterone levels in blood. Different types of motor activity are affected differentially. Hyperammonemia significantly alters the rhythm of spontaneous ambulatory activity, reducing strongly ambulatory counts and slightly average velocity during the night (the active phase) but not during the day, resulting in altered circadian rhythms. In contrast, hyperammonemia did not affect wheel running at all, indicating that it affects spontaneous but not voluntary activity. Vertical activity was affected only very slightly, indicating that hyperammonemia does not induce anxiety. Hyperammonemia abolished completely the circadian rhythm of corticosteroid hormones in plasma, completely eliminating the peaks of cortisol and corticosterone present in control rats at the start of the dark period. The data reported show that chronic hyperammonemia, similar to that present in patients with liver cirrhosis, alters the circadian rhythms of corticosteroid hormones and of motor activity. This suggests that hyperammonemia would be a relevant contributor to the alterations in corticosteroid hormones and in circadian rhythms in patients with liver cirrhosis.

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“…In this model, the neurological and behavioural alterations may be similar to those found in human type B hepatic encephalopathy, which is linked to encephalopathy related to the portosystemic shunt (17)(18)(19). It has been proposed that the alterations produced by hepatic encephalopathy may have an inflammatory nature and may be mediated by the astroglia (9).…”

Section: Portosystemic Anastomosismentioning

confidence: 86%

The value of microsurgery in liver research

Aller

Méndez

Nava

et al. 2009

Liver International

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The use of an operating microscope in rat liver surgery makes it possible to obtain new experimental models and improve the already existing macrosurgical models. Thus, microsurgery could be a very valuable technique to improve experimental models of hepatic insufficiency. In the current review, we present the microsurgical techniques most frequently used in the rat, such as the portacaval shunt, the extrahepatic biliary tract resection, partial and total hepatectomies and heterotopic and orthotopic liver transplantation. Hence, reducing surgical complications allows for perfecting the resulting experimental models. Thus, liver atrophy related to portacaval shunt, prehepatic portal hypertension secondary to partial portal vein ligation, cholestasis by resection of the extrahepatic biliary tract, hepatic regeneration after partial hepatectomies, acute liver failure associated with subtotal or total hepatectomy and finally complications derived from preservation or rejection in orthotopic and heterotopic liver transplantation can be studied in more standardized experimental models. The results obtained are therefore more reliable and facilitates the flow of knowledge from the bench to the bedside. Some of these microsurgical techniques, because of their simplicity, can be performed by researchers without any prior surgical training. Other more complex microsurgical techniques require in-depth surgical training. These techniques are ideal for achieving a complete surgical training and more select microsurgical models for hepatology research.

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Cytochrome Oxidase Activity of the Suprachiasmatic Nucleus and Pineal Gland in Rats with Portacaval Shunt

Cited by 9 publications

References 75 publications

Portosystemic hepatic encephalopathy model shows reversal learning impairment and dysfunction of neural activity in the prefrontal cortex and regions involved in motivated behavior

Portosystemic hepatic encephalopathy model shows reversal learning impairment and dysfunction of neural activity in the prefrontal cortex and regions involved in motivated behavior

Chronic hyperammonemia alters the circadian rhythms of corticosteroid hormone levels and of motor activity in rats

The value of microsurgery in liver research

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