The hippocampal region of the brain is important for encoding environment inputs and memory formation. However, the underlying mechanisms are unclear.

Dr. Zhouyan Feng and co-workers from Zhejiang University, China monitored the activity of hippocampal neurons in rats using microelectrode arrays, and explored the mechanisms underlying the neuronal responses. Somatosensory stimulation, in the form of tail clamping, changed local field potentials into theta rhythm-dominated waveforms, decreased the spike firing of pyramidal cells, and increased interneuron firing.

In addition, somatosensory stimulation attenuated orthodromic-evoked population spikes.

These results suggest that somatosensory stimulation suppresses the excitability of pyramidal cells in the hippocampal CA1 region. Increased inhibition by local interneurons might underlie this effect.

These findings, published in Neural Regeneration Research (Vol. 9, No. 11, 2014), provide insight into the mechanisms of signal processing in the hippocampus and suggest that sensory stimulation might have therapeutic potential for brain disorders associated with neuronal hyperexcitability.

Article: " Somatosensory stimulation suppresses the excitability of pyramidal cells in the hippocampal CA1 region in rats," by Yang Wang, Zhouyan Feng, Jing Wang, Xiaojing Zheng (Key Laboratory of Biomedical Engineering of Education Ministry, College of Biomedical Engineering and Instrumentation Science, Zhejiang University, Hangzhou, Zhejiang Province, China)

Wang Y, Feng ZY, Wang J, Zheng XJ. Somatosensory stimulation suppresses the excitability of pyramidal cells in the hippocampal CA1 region in rats. Neural Regen Res. 2014;9(11):1138-1144.