All classes of motor actions depend on the brain for selecting and sequencing behavior-specific muscle activity patterns. This includes vocalization, a behavior that is shared among fishes, amphibians, reptiles, birds and mammals. This remarkable behavior that includes human speech begs the general question: How do brain regions that control movement underlie our ability to select from a menu of available behavioral actions? Vocal behaviors are excellent models for answering this question because they are often highly stereotyped and differ in a small set of easily quantified properties such as frequency, amplitude and duration. There remains an astonishing lack of knowledge of how different brain regions participate in the performance of vocal behavior. This is especially the case for the midbrain that provides a key link between the cerebral hemispheres and central pattern generators found in the hindbrain and spinal cord that directly instruct the activity of muscles. Sound producing fish are champions in the ability to generate vocalizations that exhibit rapid, precisely timed sound pulses. They also provide highly tractable models for studying how the midbrain controls vocal behavior due to a well-characterized and experimentally accessible vocal central pattern generator. The project will investigate the role of the midbrain in the selection, sequencing and/or patterning of different vocal motor behaviors. The Principal Investigator will continue to recruit a talented population of students from diverse backgrounds, including under-represented minorities, and train them in problem-solving at behavioral, neural and molecular levels of analysis.

A practical way to address questions of how vocal motor systems function is to identify model systems, such as those in fish, where behavior is controlled by readily accessible brain centers that share evolutionary and developmental origins with centers in other vertebrates. This project has two aims that will use behavioral, neurophysiological and molecular methods to provide the first comprehensive analysis of how the midbrain of a highly species of vocal fish contributes to vocal motor coding and action selection. Aim 1 will map specific midbrain populations activated during different vocalizations by using immunohistochemistry to detect immediate early gene (IEG) expression, a proxy for increased neural activity, in brains collected from vocalizing fish. Aim 1 will also characterize the neurochemical signature of IEG-identified neurons by investigating co-expression with excitatory and inhibitory transmitters and select neuromodulators that are known to modulate midbrain-dependent mechanisms of vocalization. Aim 2 will then investigate the role of midbrain neuronal populations identified in Aim 1 in the selection, sequencing and/or patterning of vocal behavior by combining neurophysiology, including single neuron recording, with pharmacology to induce and modulate vocal motor activity. The results will inform us about vocal mechanisms and, more broadly, motor behaviors among all groups of vertebrates.

Agency
National Science Foundation (NSF)
Institute
Division of Integrative Organismal Systems (IOS)
Application #
1656664
Program Officer
Sridhar Raghavachari
Project Start
Project End
Budget Start
2017-08-15
Budget End
2022-07-31
Support Year
Fiscal Year
2016
Total Cost
$830,000
Indirect Cost
Name
Cornell University
Department
Type
DUNS #
City
Ithaca
State
NY
Country
United States
Zip Code
14850