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ref: -0 tags: flexible polymer neural probes compliant MIT EPFL 2008 date: 12-22-2012 01:28 gmt revision:0 [head]

Demonstration of cortical recording using novel flexible polymer neural probes

  • Two layer platinum process minimizes probe size -- nice. Might be useful for our purposes.
  • used electrochemical etching to release the lithographically patterned devices from the sacrificial aluminum layer.
  • Impedance looks pretty high -- 500k at 1kHz.
  • They talk about PCA as though it's unusual to them (?)
  • Histology uncontrolled and un-quantitiative.

{1145}
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ref: -0 tags: distrupted oscillations Mallet 2008 6-OHDA globus pallidus date: 02-29-2012 01:15 gmt revision:5 [4] [3] [2] [1] [0] [head]

PMID-19109506 Parkinsonian beta oscillations in the external globus pallidus and their relationship with subthalamic nucleus activity.

  • Rat 6-OHDA.
  • On rate model: Although synchronization of GP unit activity increased by almost 100-fold during beta oscillations, the mean firing rate of GP neurons decreased compared with controls.
  • Synchronized firing persisted across different brain states, suggesting hardwiring.
  • GP and STN are frequency aligned but phase skewed.
    • Lateral inhibition in GP seems essential / see model.
  • Suggest that GPe / STN could generate oscillations that propagate to the rest of the BG.
    • But then why is the cortex required?

{1109}
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ref: -0 tags: Cogan 2008 electrodes recording stimulation date: 02-05-2012 00:21 gmt revision:0 [head]

PMID-18429704 Neural stimulation and recording electrodes.

  • Electrical stimulation of nerve tissue and recording of neural electrical activity are the basis of emerging prostheses and treatments for spinal cord injury, stroke, sensory deficits, and neurological disorders. An understanding of the electrochemical mechanisms underlying the behavior of neural stimulation and recording electrodes is important for the development of chronically implanted devices, particularly those employing large numbers of microelectrodes. For stimulation, materials that support charge injection by capacitive and faradaic mechanisms are available. These include titanium nitride, platinum, and iridium oxide, each with certain advantages and limitations. The use of charge-balanced waveforms and maximum electrochemical potential excursions as criteria for reversible charge injection with these electrode materials are described and critiqued. Techniques for characterizing electrochemical properties relevant to stimulation and recording are described with examples of differences in the in vitro and in vivo response of electrodes.

{949}
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ref: Velliste-2008.06 tags: Schwartz 2008 Velliste BMI feeding population vector date: 01-06-2012 00:19 gmt revision:1 [0] [head]

PMID-18509337[0] Cortical control of a prosthetic arm for self-feeding

  • Idea: move BMI into robotic control.
  • population vector control, which has been shown to be inferior to the Wiener filter.
  • 112 units for control in one monkey. 2 monkeys used.
  • 4D control -- x, y, z, gripper.
  • 1064 trials over 13 days, average success rate of 78%
  • Gripper opened as the arm returned to mouth. Works b/c marshmallows are sticky.

____References____

[0] Velliste M, Perel S, Spalding MC, Whitford AS, Schwartz AB, Cortical control of a prosthetic arm for self-feeding.Nature 453:7198, 1098-101 (2008 Jun 19)