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

TL;DR

This study demonstrates that a portosystemic hepatic encephalopathy rat model exhibits reversal learning deficits and reduced neural activity in key brain regions involved in motivation and cognition.

Contribution

It provides evidence linking neural activity dysfunction in specific brain areas to learning impairments in a hepatic encephalopathy model.

Findings

Reversal learning is impaired in PCS rats.

Cytochrome oxidase activity is reduced in prefrontal cortex, ventral tegmental area, and nucleus accumbens.

Neural dysfunction correlates with cognitive deficits.

Abstract

Hepatic encephalopathy is a neurological complication that affects attention and memory. Experimental animal models have been used to study hepatic Encephalopathy, the most frequent being the portacaval shunt. In order to determine learning impairment and brain functional alterations in this model, we assessed reversal learning and neural metabolic activity in a PCS rat model. Portacaval shunt and sham-operated rats were tested for reversal learning in the Morris water maze. Brains were processed for cytochrome oxidase histochemistry. The portacaval shunt group presents reversal learning impairment and cytochrome oxidase activity reduction in prefrontal cortex, ventral tegmental area and accumbens shell nucleus. These results suggest that this model of portosystemic hepatic encephalopathy shows learning impairment that could be linked to dysfunction in neural activity in the prefrontal cortex and regions involved in motivated behavior.