Lingjun Li

Lingjun Li
Professor, Department of Pharmacy
(608) 265-8491


Ph.D. University of Illinois at Urbana-Champaign

Lab Website:

Research Focus:

Peptidomics, Neuromodulation and Endocrine Regulation of Neural Networks

Research Strengths:

Molecular Neuroscience; Neural Circuits

Research Description:

One of the most striking features of biological brains is that neurons contain and release a very large number of neurotransmitters and neuromodulators. Our research aims at developing a novel mass spectrometry-based proteomics approach to answer questions about the most complex and elusive set of neuromodulators, the neuropeptides, and gain new insights into the roles of peptide modulators play in the behavior of the neuronal circuitry.

The crustacean stomatogastric nervous system (STNS) is an excellent model system for studying the neural basis of rhythmic behavior and it is also an ideal system to investigate neuromodulation in a well-defined neural network. This is an attractive preparation because of the limited number of neurons whose electrophysiological properties can be readily assessed and yet an amazingly large number of peptide neuromodulators are involved in this small neural network. However, we are far from having a complete description of all the neurotransmitters and neuropeptides contained in the STNS, which is crucial for understanding the mechanisms by which this hard-wired, pattern-generating circuitry is functionally modulated. We are developing an array of enabling mass spectrometric tools coupled with front-end microseparation strategies and back-end bioinformatics tools to provide a unique and global view of the diverse assortment of peptides contained within a small neuronal network. Once the chemical identities of the peptides are established, peptide colocalization pattern and release at the cellular and network level will be studied. Thus, our research will help to define completely how the full range of behaviors produced by a neural circuit is specified or encoded by the modulatory environment. While the functional consequences of the large diversity of neuropeptides in the nervous systems is still not fully understood, as we continue to discover and study the functional roles of additional neuropeptides and their presence in identified projection neurons, we will uncover the rules by which biological circuits can be so flexible and yet so stable in its actions. 


Please see PubMed for most recent publications