title: Impairment of short term memory in rats with hepatic encephalopathy due to bile duct ligation.
abstract: Hepatic encephalopathy (HE) arises from acute or chronic liver diseases and leads to cognitive deficits. Different animal models for the study of HE have demonstrated learning and memory impairment and a number of neurotransmitter systems have been proposed to be involved in this. Recently, it was described that bile duct-ligated (BDL) rats exhibited altered spatio-temporal locomotor and exploratory activities and biosynthesis of neurotransmitter GABA in brain cortices. Therefore, the aim of this study was to evaluate cognition in the same animal model. Male adult Wistar rats underwent common bile duct ligation (BDL rats) or manipulation of common bile duct without ligation (control rats). Six weeks after surgery, control and BDL rats underwent object recognition behavioral task. The BDL rats developed chronic liver failure and exhibited a decreased discrimination index for short term memory (STM) when compared to the control group. There was no difference in long term memory (LTM) as well as in total time of exploration in the training, STM and LTM sessions between the BDL and control rats. Therefore, the BDL rats demonstrated impaired STM for recognition memory, which was not due to decreased exploration.
authors.affiliation: Experimental Hepatology and Gastroenterology Laboratory, Research Center of Hospital de Clínicas de Porto Alegre, Avenida Ramiro Barcelos, 2350, Porto Alegre, Rio Grande do Sul 90035-903, Brazil. renataleke@hotmail.com
authors.forename: Renata
authors.initials: R
authors.lastname: Leke
authors.forename: Diogo L
authors.initials: DL
authors.lastname: Oliveira
authors.forename: Luiz F
authors.initials: LF
authors.lastname: Forgiarini
authors.forename: Thayssa D C
authors.initials: TD
authors.lastname: Escobar
authors.forename: Thais O
authors.initials: TO
authors.lastname: Hammes
authors.forename: Fabíola S
authors.initials: FS
authors.lastname: Meyer
authors.forename: Susanne
authors.initials: S
authors.lastname: Keiding
authors.forename: Themis R
authors.initials: TR
authors.lastname: Silveira
authors.forename: Arne
authors.initials: A
authors.lastname: Schousboe
mesh_terms: D000641:Ammonia / Q000097:blood; D000818:Animals; D001652:Bile Ducts / Q000502:physiology*; D058625:End Stage Liver Disease / Q000523:psychology; D006501:Hepatic Encephalopathy / Q000209:etiology / Q000523:psychology*; D022124:Hyperammonemia / Q000097:blood / Q000209:etiology; D008026:Ligation; D008297:Male; D008569:Memory Disorders / Q000139:chemically induced* / Q000523:psychology*; D008570:Memory, Short-Term / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D021641:Recognition, Psychology / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology
chemical_list: D000641:Ammonia