Graduation Date

Spring 2023

Document Type



Master of Arts degree with a major in Psychology, option Academic Research

Committee Chair Name

Dr. Ethan Gahtan

Committee Chair Affiliation

HSU Faculty or Staff

Second Committee Member Name

Dr. Amanda Hahn

Second Committee Member Affiliation

HSU Faculty or Staff

Third Committee Member Name

Dr. Amber Gaffney

Third Committee Member Affiliation

HSU Faculty or Staff


Area postrema, MS-222, Zebrafish, Anesthesia, Sedation, Voltage-gated sodium channel, Circumventricular organ, Calcium imaging, GCaMP

Subject Categories



MS-222 is a common fish anesthetic that dampens neural activity by inhibiting neuronal voltage-gated sodium channels (Nav) required for action potentials. Previous experiments conducted by our lab’s primary investigator using fluorescence calcium imaging in zebrafish neurons resulted in the observation that neurons in the area postrema (AP), a circumventricular organ located in the dorsal hindbrain, displayed prominent fluorescence intensity during MS-222 induced sedation. I used the genetically encoded calcium indicator GCaMP6s to conduct fluorescence calcium imaging with the goal of recording neural activity in the larval zebrafish area postrema and optic tectum to compare the anesthetic effects of MS-222 across brain regions. A 2 x 2 analysis of variance (ANOVA) was used to calculate the differences in fluorescence intensity before and after MS-222 in both brain regions. Contrary to our hypothesis, the results of the experiment indicate that MS-222 had an insignificant effect on the change in fluorescence intensity in each brain region and although insignificant, appears to slightly increase area postrema and optic tectum mean standard deviations. These results are theoretically inconsistent with the literary understanding of how voltage-gated sodium channel antagonism affects cellular behavior. A small sample size with high variance is the most likely explanation for these results.

Citation Style




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