Entropy Coding of Neuron Firings at Hippocampus CA1 for Memory Dysfunctional Mice

The aim of this research is to investigate the characterization of firing pattern of neuron at CA1 for dysfunctional memory mice via entropy coding. The spike trains were recorded at CA1 of hippocampus slice for two groups: senescence-accelerated-prone (SAM) –P/8 type (SAM-P/8) mice group and normal control mice group. Shannon entropy based on inter spike intervals (ISIs) histogram was used to measure the code of neuron activity at CA1 of hippocampus slice for two groups (10 samples for each group). The different of the entropy codes for two groups was tested by t-test. The results show that Shannon entropy forSAM-P/8 mice group was 9.30±0.44 bit, which is apparently greater than that for normal mice group, which was 7.26±0.33 bit.The conclusion is that the higher entropy value for SAM-P/8 mice group is revealed lower information  level than the normal group, which suggests the dysfunction of synaptic plasticity for senescence-accelerated-prone mice. The results might support the research of memory dysfunction from the view of neural coding pattern.