Fast Gamma Oscillations Are Generated Intrinsically in CA1 without the Involvement of Fast-Spiking Basket Cells
CoolLED featured paper May 2016.
Michael T. Craig and Chris J. McBain
The Journal of Neuroscience, February 25, 2015 • 35(8):3616 –3624
Neuronal responses to stimulus and inhibition occurs in coordination with the regional network of neurons. Recently a combined approach of genetic identification of cell types, traditional patch clamp and local application of stimulus has allowed a detailed investigation of cell-type response. However, a clear goal is to record from one specific cell type while manipulating other cells in the network to determine certain cell types’ role in a coordinated response.
In this beautiful paper, the researchers wished to assess gamma oscillations in the hippocampus and found that the cells did not require basket cells to evoke the oscillations. To determine this, they used CRE based genetic methods to label cell types, so they knew the precise cell type they were recording from. They then used local drug application (kainite) to the region to generate the rhythmic activity and measured the local field potentials (response).
The next challenge was to be able to selectively modulate a different cell type to determine its role in the network while recording from the initial cell type. To achieve the second selective modulation, they utilised Optogenetic methods, where light modulated (using a CoolLED pE-4000 580nm LED) channels can evoke activation or inhibition without traditional direct-contact methods.
This paper is a good example of marrying genetic labelling of cells, traditional electrophysiology recording techniques and recent advances incorporating optogenetic techniques.
Dr Robert Hartley, CoolLED Ltd
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