Combining Microdialysis and Electrophysiology in Cerebral Cortex to Delineate Functional Implications of Acetylcholine Gradients

Student: Tazima Nur

Degree: Ph.D., May 2018

Major Professor: Dr. Woodrow Shew

Research Area(s):

Biological Materials & Processes

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Background/Relevance

  • Neural response changes from trial to trial for repeated sensory stimulus.
  • Cholinergic neuromodulation induces cortical state change.
  • Hypothesis cortical state is heterogeneous across the spatialextent of the cortical network and this heterogeneity enablesthe cortical network to maintain reliable sensory detection.

Innovation

  • A novel combination of microelectrode array (MEA) and microdialysis ( µD) probes for precision chemical and electrophysiological measurements.

Approach

  • Implant the device in rat brain.
  • Control ACh concentration via µD probes.
  • Measure the neural activity in terms of action potentials via MEA in response to whisker simulation under varying chemical conditions.

Conclusions

  • Cortical state is spatially inhomogeneous across the cortical network.
  • Changes in ACh spatial distribution pattern lead to different cortical states at different locations in the cortical network.
  • The heterogeneity in cortical state allowed for reliable population level detection despite unreliable detection at the level of single electrodes.