Discharge characteristics of rat hippocampus CA1 area place cells in adaptation to visual-vestibular-proprioceptive sensory mismatch / 第二军医大学学报

ABSTRACT

Objective: To study the discharge changes of CA1 area place cells after hippocampal formation (HF) accepting the visua--vestibular-proprioceptive mismatch configuration as a match by learning, so as to provide evidence that HF may encode any combination of sensory inputs. Methods: The visual-vestibular-proprioceptive mismatch configuration was set up. According to θ rhythm recording and θ power calculation in rat hippocampal dentate gyrus, adaptation to the sensory conflict could be confirmed. The assembly discharge of CA1 area place cells was recorded in awake rats by using extracellular tungsten microelectrode record and stereotaxic techniques after the ratsa dapted to sensory mismatch. Results: Of the 56 place cells, 14 (25.0%) showed consistent spatial firing in both the match and mismatch conditions (bi-directional movement-related experience-independent neurons); 33 (58.9%) showed different spatial firings across the sessions (bi-directional movemen--related experience-dependent neurons). The mean sizes and mean value of index of asymmetry of the place fields were larger in bi-directional movement-related neurons than that in experience-dependent neurons (P<0.01, P<0.05). The firing rate distributions in the place fields were negatively skewed and asymmetric. Conclusion: The HF encodes a naturally impossible new configuration of sensory inputs after adaptation, and it can update the stored memory to accept a new configuration as a match. The HF may encode any combination of sensory inputs.