This is the lab page of David T Blake, PhD. The lab investigates questions concerning brain electrophysiology and behavior. The most recent focus has been on basal forebrain deep brain stimulation, its physiological and behavioral effects, and the potential to use such deep brain stimulation to treat neurological disorders. Honestly, I think it is going to cure Alzheimer's, and by that I mean its application in patients will prevent cognitive decline from altering their activities of daily living. Human trials of our methods are ongoing in some centers. If you would like to apply our methods to your human trials, contact me. |
Main questions for the lab |
How is learning expressed in areas of the cerebral cortex that are wired differently e.g., sensory vs association cortex, i and how is learning modulated by acetylcholine, dopamine, and noradrenaline? |
Weeks of application of deep brain stimulation can dramatically improve executive function even in fully functioning young adults. Can it do the same in Alzheimer's patients? |
What do we need to know about learning rules in sensory cortex to build machine learning models that perform human-equivalent sensory discrimination? |
What are the cell biological pathways involved in instantiating those learning rules? |
What are the machine learning concepts embodied by those learning rules? What are their limitations? Mathematically, how can we optimize them? And how can we combine them with other neural network concepts to build a biologically based machine learning network that performs human equivalent sensory discrimination? Or discrimination that is better than human equivalent? |
In 1996, I went to the lab of Michael Merzenich. There, with R. Christopher deCharms, we succeeded in developing one of the earliest high yield sensory cortex implants. The following experiments, done also with fabrizio strata, Anne Churchland, and Richard Kempter, were among the first to resample, with high spatial resolution, the same cortical locations throughout a period of learning. The discoveries that followed were unexpected. A robust nonselective response enhancement occurred within 24 hours of the time that an animal learned to associate a new sensory stimulus with reward. Over longer periods of time, the representations of stimuli associated with omission of reward, or task distractors, became selectively suppressed. Surprisingly, any tendency for the representations of targets to be enhanced, relative to the representations of control stimuli, were weak or absent. The following figure, taken from Blake et al 2002, shows the rapidity and strength of the nonselective response enhancement. Cortical responses double in 24 hours after learning. |
Current work occurs in the mouse lab, led by Khadijah Shanazz,
PhD.
She uses the GACh3.0 sensor in cerebral cortex, and also places a
stimulating electrodes in the basal forebrain. She can stimulate
and image the cholinergic response to stimulation each 0.6
seconds.
One paper is on BioRXiV, and she has recently added two
things to her studies. She measures the vascular response to
stimulation at the same time as the cholinergic response, and she
transitioned to working with awake mice. We've received a lot of
help from the labs of Sergei Kirov and Phil O'Herron in getting
things working, and they are supportive co-authors. Dr. Shanazz can be emailed as kshanazz AT augusta |
The work in the monkey lab is led by graduate student Kendyl
Pennington. She has a paper
on BioRXiV also, and hers details the
changes in senescent macaques after deep brain stimulation of the
nucleus basalis of Meynert is applied. Her upcoming project
samples cerebrospinal fluid before, during, and after deep brain
stimulation. She is looking at changes in the proteome of the
fluid as indications of processes occuring in the chemical
communication between neurons and other cells in the neuropil. We
are particularly interested if there are clues to the causes of
Alzheimer's dementia that are reflected by the proteome of the
CSF fluid. Stay tuned for answers! Kendyl can be emailed as kpennington AT augusta |