title: Unilateral hippocampal inactivation or lesion selectively impairs remote contextual fear memory.
abstract: Contextual fear memory depends on the hippocampus, but the role of unilateral hippocampus in this type of memory remains unclear.
  
  
  
  Herein, pharmacological inactivation or excitotoxic lesions were used to study the role of unilateral hippocampus in the stages of contextual fear memory.
  
  
  
  The pharmacological experiments revealed that compared with the control groups, unilateral hippocampal blockade did not impair 1-day recent memory following learning, whereas bilateral hippocampal blockade significantly impaired this memory. The lesion experiments showed that compared with the control groups, the formed contextual fear memory was retained for 7 days and that 30-day remote memory was markedly reduced in unilateral hippocampal lesion groups.
  
  
  
  These results indicate that an intact bilateral hippocampus is required for the formation of remote memory and that unilateral hippocampus is sufficient for recent contextual fear memory.
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, People's Republic of China.|Laboratory of Learning and Memory, Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, CAS, Kunming, 650223, People's Republic of China.
authors.forename: Heng
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Laboratory of Learning and Memory, Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, CAS, Kunming, 650223, People's Republic of China. qixin_zhou@126.com.
authors.forename: Qixin
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Laboratory of Learning and Memory, Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, CAS, Kunming, 650223, People's Republic of China. lxu@vip.163.com.|Kunming College of Life Sciences, University of Chinese Academy of Sciences, Kunming, People's Republic of China. lxu@vip.163.com.
authors.forename: Lin
authors.initials: L
authors.lastname: Xu
mesh_terms: D000818:Animals; D003213:Conditioning, Psychological; D005239:Fear / Q000502:physiology*; D058785:GABA-A Receptor Agonists / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D008568:Memory; D057567:Memory, Long-Term / Q000187:drug effects / Q000502:physiology*; D009118:Muscimol / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D058785:GABA-A Receptor Agonists; D009118:Muscimol
keywords: Bilateral hippocampus; Fear memory; Recent memory; Remote memory; Unilateral hippocampus