Anatol Kreitzer joins GIND
The nervous system is extremely complicated. The basic unit of the system is the neuron. The many finger-like projections on neurons usually include one long axon and many dendrites. They join at connections called synapses, where neurotransmitters are released by vesicles or taken up by receptors to transmit the signal.
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Anatol C. Kreitzer, PhD, has accepted an appointment as an assistant investigator in the Gladstone Institute of Neurological Disease (GIND). Dr. Kreitzer was formerly a postdoctoral fellow in the Department of Psychiatry and Behavioral Sciences at Stanford University. He joined Gladstone in February 2007. “We are extremely pleased that Dr. Kreitzer has joined our Institute,” said Lennart Mucke, GIND director. “His research on the regulation of synapses will add another exciting dimension to our studies. It will help us understand motor control and neurodegenerative disorders at the level of neural networks.” The brain is made up of millions of cells that connect with each other to form thoughts and memories. The number and strength of these myriad connections allow us to integrate sensory |
 Anatol Kreitzer takes movement very seriously, whether he is climbing the rocky face of a mountain, whipping along on his kite board in San Francisco Bay, or thinking about his research into how movement is controlled by the brain. |
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inputs, transmit information, and create intelligent behaviors and consciousness. It also controls our movements. Dr. Kreitzer studies the nature of synapses and how they are dynamically regulated by electrical activity or modulated by drugs. “The focus of my research is the endogenous cannabinoid signaling system,” he says. “Endocannabinoids are similar to the active ingredient of marijuana, but are produced by the brain, particularly in the striatum, a brain region that is involved in motor coordination and learning.”
Endocannabinoids are produced by cells called “medium spiny neurons” in response to heightened activity. Upon release, they can bind to cannabinoid receptors on nearby cells that are connected to the medium spiny neuron. When receptors on the other cells are activated, the connection to the medium spiny neuron is weakened. In this way, endocannabinoids provide a negative feedback mechanism, allowing cells in the brain to remain responsive over a wide range of input intensities, and in extreme cases, protecting the neurons from cell death. |
 At a synapse, chemical modulators can alter signal transmission from one neuron to another. At the presynaptic terminal (left panel), cannabinoid receptors can inhibit the release of neurotransmitter. Endocannabinoids originate from the postsynaptic cell (right panel), where they are released and act at the presynaptic terminal. |
In a recent study published in Nature, Dr. Kreitzer and Dr. Robert Malenka at Stanford examined the effects of endocannabinoids on movement in a model of Parkinson's disease. Two different brain circuits are involved in the normal control of movement. One circuit, termed the “direct pathway,” helps select wanted movements, whereas the other circuit, termed the “indirect pathway,” inhibits unwanted movements. Endocannabinoids are produced in the indirect pathway in response to the brain chemical dopamine, which makes the control of movements smooth and swift. | |
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However, in Parkinson's disease, dopamine is lost, and even wanted movements become difficult to achieve. By giving a combination of drugs that enhanced both dopamine and endocannabinoid signaling, Drs. Kreitzer and Malenka found dramatic improvements in parkinsonian mice.
Dr. Kreitzer came to the study of the brain by a circuitous route. He earned a BA with honors in linguistics with a minor in German from UC Berkeley. |
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“It's not as strange as it might seem. Language is one of the keys to understanding how the brain processes information,” he says. He then earned a PhD in neurobiology from Harvard University under the direction of Dr. Wade Regehr and completed his postdoctoral training at Stanford with Dr. Malenka.
“I am excited about the opportunity to continue my work at Gladstone,” said Dr. Kreitzer. “I look forward to becoming part of Gladstone and UCSF at Mission Bay.” |