title: Voluntary Running Exercise-Mediated Enhanced Neurogenesis Does Not Obliterate Retrograde Spatial Memory.
abstract: Running exercise (RE) improves cognition, formation of anterograde memories, and mood, alongside enhancing hippocampal neurogenesis. A previous investigation in a mouse model showed that RE-induced increased neurogenesis erases retrograde memory (Akers et al., 2014). However, it is unknown whether RE-induced forgetting is common to all species. We ascertained whether voluntary RE-induced enhanced neurogenesis interferes with the recall of spatial memory in rats. Young rats assigned to either sedentary (SED) or running exercise (RE) groups were first subjected to eight learning sessions in a water maze. A probe test (PT) conducted 24 h after the final training session confirmed that animals in either group had a similar ability for the recall of short-term memory. Following this, rats in the RE group were housed in larger cages fitted with running wheels, whereas rats in the SED group remained in standard cages. Animals in the RE group ran an average of 78 km in 4 weeks. A second PT performed 4 weeks after the first PT revealed comparable ability for memory recall between animals in the RE and SED groups, which was evidenced through multiple measures of memory retrieval function. The RE group displayed a 1.5- to 2.1-fold higher hippocampal neurogenesis than SED rats. Additionally, both moderate and brisk RE did not interfere with the recall of memory, although increasing amounts of RE proportionally enhanced neurogenesis. In conclusion, RE does not impair memory recall ability in a rat model despite substantially increasing neurogenesis.
  
  
  
  Running exercise (RE) improves new memory formation along with an increased neurogenesis in the hippocampus. In view of a recent study showing that RE-mediated increased hippocampal neurogenesis promotes forgetfulness in a mouse model, we ascertained whether a similar adverse phenomenon exists in a rat model. Memory recall ability examined 4 weeks after learning confirmed that animals that had run a mean of 78 km and displayed a 1.5- to 2.1-fold increase in hippocampal neurogenesis demonstrated similar proficiency for memory recall as animals that had remained sedentary. Furthermore, both moderate and brisk RE did not interfere with memory recall, although increasing amounts of RE proportionally enhanced neurogenesis, implying that RE has no adverse effects on memory recall.
authors.affiliation: Institute for Regenerative Medicine, Texas A&M Health Science Center College of Medicine at Scott and White, Temple, Texas 76502, Research Service, Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System, Temple, Texas 76502, and Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine, College Station, Texas 77843.
authors.forename: Maheedhar
authors.initials: M
authors.lastname: Kodali
authors.affiliation: Institute for Regenerative Medicine, Texas A&M Health Science Center College of Medicine at Scott and White, Temple, Texas 76502.
authors.forename: Tarick
authors.initials: T
authors.lastname: Megahed
authors.affiliation: Institute for Regenerative Medicine, Texas A&M Health Science Center College of Medicine at Scott and White, Temple, Texas 76502, Research Service, Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System, Temple, Texas 76502, and Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine, College Station, Texas 77843.
authors.forename: Vikas
authors.initials: V
authors.lastname: Mishra
authors.affiliation: Institute for Regenerative Medicine, Texas A&M Health Science Center College of Medicine at Scott and White, Temple, Texas 76502, Research Service, Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System, Temple, Texas 76502, and Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine, College Station, Texas 77843.
authors.forename: Bing
authors.initials: B
authors.lastname: Shuai
authors.affiliation: Institute for Regenerative Medicine, Texas A&M Health Science Center College of Medicine at Scott and White, Temple, Texas 76502, Research Service, Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System, Temple, Texas 76502, and Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine, College Station, Texas 77843.
authors.forename: Bharathi
authors.initials: B
authors.lastname: Hattiangady
authors.affiliation: Institute for Regenerative Medicine, Texas A&M Health Science Center College of Medicine at Scott and White, Temple, Texas 76502, Research Service, Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System, Temple, Texas 76502, and Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine, College Station, Texas 77843 Shetty@medicine.tamhsc.edu.
authors.forename: Ashok K
authors.identifier: 0000-0001-5049-6671
authors.initials: AK
authors.lastname: Shetty
mesh_terms: D000818:Animals; D005108:Extinction, Psychological / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology*; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology; D055495:Neurogenesis / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D012420:Running / Q000502:physiology*; D065852:Spatial Memory / Q000502:physiology*; D013647:Task Performance and Analysis; D014836:Volition
keywords: forgetting; hippocampal neurogenesis; memory recall; memory retrieval; running exercise; water maze test