Hippocampal replay

Hippocampal replay is a phenomenon observed in rats, mice,[1] cats, rabbits,[2] songbirds[3] and monkeys.[4] During sleep or awake rest, replay refers to the re-occurrence of a sequence of cell activations that also occurred during activity, but the replay has a much faster time scale. It may be in the same order, or in reverse. Cases were also found where a sequence of activations occurs before the actual activity, but it is still the same sequence. This is called preplay.

The phenomenon has mostly been observed in the hippocampus, a brain region associated with memory and spatial navigation. Specifically, the cells that exhibit this behavior are place cells, characterized by reliably increasing their activity when the animal is in a certain location in space. During navigation, the place cells fire in a sequence according to the path of the animal. In a replay instance, the cells are activated as if in response to the same spatial path, but at a much faster rate than the animal actually moved in.

  1. ^ Buhry L, Azizi AH, Cheng S (2011). "Reactivation, replay, and preplay: how it might all fit together". Neural Plasticity. 2011: 1–11. doi:10.1155/2011/203462. PMC 3171894. PMID 21918724.
  2. ^ Nokia MS, Penttonen M, Wikgren J (August 2010). "Hippocampal ripple-contingent training accelerates trace eyeblink conditioning and retards extinction in rabbits". The Journal of Neuroscience. 30 (34): 11486–92. doi:10.1523/JNEUROSCI.2165-10.2010. PMC 6633352. PMID 20739570.
  3. ^ Dave AS, Margoliash D (October 2000). "Song replay during sleep and computational rules for sensorimotor vocal learning". Science. 290 (5492): 812–6. Bibcode:2000Sci...290..812D. doi:10.1126/science.290.5492.812. PMID 11052946.
  4. ^ Skaggs WE, McNaughton BL, Permenter M, Archibeque M, Vogt J, Amaral DG, Barnes CA (August 2007). "EEG sharp waves and sparse ensemble unit activity in the macaque hippocampus". Journal of Neurophysiology. 98 (2): 898–910. doi:10.1152/jn.00401.2007. PMID 17522177.