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

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.