Fluorescent substrates for imaging neurotransmission

This technology describes the synthesis and characterization of fluorescent compounds that are substrates for monoamine transporters and can be used for direct imaging of neurotransmission at the synapse level.

Unmet Need: Quantitative assay for observing neurotransmission

Current methods to study neurotransmission allow observation and measurement of post-synaptic activity such as vesicle-membrane fusion but there are no methods for directly observing neurotransmitter release from individual synapses at the pre-synaptic terminal. Monoamine neurotransmitters such as dopamine are particularly difficult to quantify using existing methods due to toxicity, low efficiency, low specificity, and poor spatial resolution.

The Technology: Fluorescent false neurotransmitters for imaging neurotransmission

This technology identifies fluorescent compounds that accumulate in synaptic vesicles, allowing for direct visualization of neurotransmitter transport in individual dopamine terminals. These fluorescent false neurotransmitters, like dopamine, bind to the synaptic vesicular monoamine transporter (VMAT2) and other aminergic transporters, resulting in selective accumulation in dopamine terminals. As such, neurotransmitter uptake, redistribution, and release can be observed and measured with high resolution based on changes in fluorescence.

This technology has been validated by imaging VMAT2 activity in neurons in cell culture, primary neuronal cultures, and mouse brain slices.

Applications:

• Drug development tool for identifying enhancers and inhibitors of monoamine transport
• Discovery of drugs targeting dopamine transporters and receptors for the treatment of Parkinson’s disease, bipolar disorder, schizophrenia, ADHD, and neurodegenerative diseases
• Probes to study the dynamics of monoamine neurotransmission with single synapse resolution
• Research tool for studying neuronal pathways, development, and learning
• Diagnostic probes for identifying early pathologies in metabolism and synaptic transmission in neurological and psychiatric disorders

Advantages:

• Directly reports vesicle content and neurotransmitter release from individual synapses
• Quantifiable
• High spatial resolution
• Highly specific probes
• Does not interfere with normal synaptic function
• Excitation and emission within the visible spectrum

Lead Inventor:

Dalibor Sames, Ph.D.

Patent Information:

Patent Status

Related Publications:

• Pereira DB, Schmitz Y, Mészáros J, Merchant P, Hu G, Li S, Henke A, Lizardi-Ortiz JE, Karpowicz RJ Jr, Morgenstern TJ, Sonders MS, Kanter E, Rodriguez PC, Mosharov EV, Sames D, Sulzer D. “Fluorescent false neurotransmitter reveals functionally silent dopamine vesicle clusters in the striatum” Nat Neurosci. 2016 Apr; 19(4): 578-586.

• Hu G, Henke A, Karpowicz RJ Jr, Sonders MS, Farrimond F, Edwards R, Sulzer D, Sames D. “New fluorescent substrate enables quantitative and high-throughput examination of vesicular monoamine transporter 2 (VMAT2)” ACS Chem Biol. 2013 Sep 20; 8(9): 1947-1954.

• Rodriguez PC, Pereira DB, Borgkvist A, Wong MY, Barnard C, Sonders MS, Zhang H, Sames D, Sulzer D. “Fluorescent dopamine tracer resolves individual dopaminergic synapses and their activity in the brain” Proc Natl Acad Sci U S A. 2013 Jan 15; 110(3): 870-875.

• Lee M, Gubernator NG, Sulzer D, Sames D. “Development of pH-responsive fluorescent false neurotransmitters” J Am Chem Soc. 2010 Jul 7; 132(26): 8828-8830.

• Gubernator NG, Zhang H, Staal RG, Mosharov EV, Pereira DB, Yue M, Balsanek V, Vadola PA, Mukherjee B, Edwards RH, Sulzer D, Sames D. “Fluorescent false neurotransmitters visualize dopamine release from individual presynaptic terminals” Science. 2009 Jun 12; 324(5933): 1441-1444.

Tech Ventures Reference:

• IR M06-109-a

• Licensing Contact: Beth Kauderer