IAB Research Project Description

Evaluating a Raphé Chemosensory Amplifier Network with Multi-Channel Array Recording

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Knowledge of the mechanisms with which the brain detects and responds to changes in carbon dioxide and pH - called central chemosensitivity - is critical to understanding how the body maintains homeostasis and the nature of diseases resulting from failures in chemosensitivity, such as sleep apnea, Congenital Central Hypoventilation Syndrome and the Sudden Infant Death Syndrome. 
An area of the brain stem called the medullary raphé, contains neurons which synthesize the  neurotransmitter serotonin (5HT) or γ-aminobutyric acid (GABA) and which are thought to be first-order chemosensory neurons sensitive to CO2/pH. 
Unknown, however, are the critical potential reciprocal interactions between first-order neurons, and the role of second-order chemosensory neurons that may integrate, amplify and coordinate activities of first-order neurons, to modulate homeostatic reflex responses to chemosensory stimuli. 
Our overarching hypothesis is that first-order raphé 5HT and GABA chemosensory neurons interact and drive a specific population of second-order neurons in a local network we term the raphé chemosensory amplifier.
Our project has two aims, to determine that; (1) Intrinsic sensitivity of raphé 5HT and GABA neurons is shaped by the RCA network. (2) RCAI integrate and amplify inputs from first-order 5HT and/or GABA neurons.
Proposed studies will confirm and characterize, or refute the existence of critical network interactions within the raphé influencing chemoresponsiveness of neurons when within an intact nervous system. Results will test the validity of the RCA model, and will suggest an organization of  the raphé chemosensory system and advance the understanding of central chemoreception by contributing definitive information about the network characteristics involved in this vital process.

Project Funding

NIH, National Institutes of Health
1 Apr 2015 – 31 Dec 2017
IAB Proposal #2014-094
UAF Grant #G10033
IAB Project #311

Media Contact

Marie Thoms
Communications/Web Manager
Institute of Arctic Biology
302A Irving I
University of Alaska Fairbanks
Fairbanks, AK 99775-7000
email: methoms@alaska.edu
phone: 907.474.7412