Development of Surgical Techniques and Behavioral Methods to Explore Adult Rat Vocal Production Open Access

Abstract

Similar to how humans show emotions through different vocalizations, rats and other rodents have different vocal responses based on varying affective states. In addition to producing audible squeaks and calls, rats can communicate by producing ultrasonic vocalizations (USVs). These vocalizations are inaudible to humans and occur in the 20 - 100 kHz frequency range. Adult rats produce USVs divided into two general frequency classes, 50 kHz or 22 kHz, which generally correlate to different emotional states. Fifty kHz vocalizations are often associated with appetitive/rewarding emotions evoked by positive situations, whereas 22 kHz vocalizations often correlate to aversive emotions and environments. Analysis of USVs serves an important role in many laboratory studies across multiple scientific areas and is used to address questions related to the internal states of the rat, vocal motor output, and social behavior. The mechanism the larynx uses to produce USV in rats is just beginning to be understood. To aid in completing our own studies and those in other labs, we are developing a general protocol to measure the muscle activity of the larynx during USV production. To study how muscle movements in the larynx elicit different frequencies of USVs in rats, behavioral and surgical techniques are crucial to perform and understand this goal. To this end, we have taken two major steps: developing behavioral paradigms that optimize the elicitation of USVs (Aim 1) and performing surgical techniques to access different intrinsic laryngeal muscles in rats to perform EMG recording (Aim 2). The development of Aim 1 allows experimenters to successfully produce USVs in rats with highly variable vocalizations based on the specific personality of the animal. Aim 2 specifically targets intrinsic laryngeal muscles of interest that aid in the production of USVs: cricothyroid (CT), posterior cricoarytenoid (PCA), and thyroarytenoid (TA).

Table of Contents

Introduction - 1   

A. Intraspecies Vocalization - 1    

B. Ultrasonic Vocalizations - 1    

C. Vocal Production Mechanism - 4   

D. USV Production Mechanism - 8     

E. Study Aims - 10

Methods - 12

A. Subjects and Housing - 12  

B. Recording USVs and EMG - 12   

C. Electrode Array Preparation - 14 

D. Dissection - 15

E. General Surgical Procedure - 16

Results - 21

A. Aim 1 (Behavioral Results) - 21

B. Aim 2 (Surgical Results) - 29

Discussion - 37  

A. EMG Recordings after Array Implementation - 37

B. Social Dominance Observations - 38

C. Study Limitations - 39 

D. Future Directions - 40

References - 43 

About this Honors Thesis

Rights statement

• Permission granted by the author to include this thesis or dissertation in this repository. All rights reserved by the author. Please contact the author for information regarding the reproduction and use of this thesis or dissertation.

School	Emory College
Department	Biology
Degree	B.S.
Submission	Honors Thesis
Language	English
Research Field	Biology, General
Keyword	Intrinsic Laryngeal Muscles Ultrasonic Vocalizations Rat
Committee Chair / Thesis Advisor	Sober, Sam, Emory University
Committee Members	Civitello, Dave, Emory University Klein, Adam, Emory University

Last modified

Primary PDF

Thumbnail	Title	Date Uploaded	Actions
	Development of Surgical Techniques and Behavioral Methods to Explore Adult Rat Vocal Production ()	2024-04-12 22:27:43 -0400	Press to Select an action Download

Supplemental Files

Thumbnail	Title	Date Uploaded	Actions