Spikelets and Place Cells

Spikelets are a small all-or-none signal in brain cells (neurons) thought to be distinct from spikes (technically called action potentials). A paper from earlier this year suggests that spikelets are important participants in signal processing in the brain.

(The paper is “Impact of Spikelets on Hippocampal CA1 Pyramidal Cell Activity During Spatial Exploration” published January 22, 2010 in Science.)

The research team recorded from inside neurons of awake and behaving rats to assess the role of spikelet activity while the animals moved through and explored their environment. Some evidence suggested that spikelets sometimes induced a spike to occur. They also saw spikelet activity show preference for place like with action potentials.

Intriguing but where are these spikelets coming from? Are these correlations without causation? Various suggestions for how spikelets are generated include:

  • they result from direct action potential transmission through electrical coupling between cells
  • they are spikes being recorded long distance from the electrode in the cell body. Perhaps from the cell’s dendrites or axon.

Spikelets may be important signals or they may be epiphenomena. What do you think?

Other related blog posts:

Do You Know Where You Are? Place Memory

Nature versus Nurture and Place Memory Development