Dopamine modulation of escape movements in larval zebrafish
Graduation Date
2012
Document Type
Thesis
Program
Other
Program
Thesis (M.A.)--Psychology, Academic Research: Biological Psychology, 2012
Committee Chair Name
Ethan Gahtan
Committee Chair Affiliation
HSU Faculty or Staff
Keywords
Humboldt State University -- Theses -- Psychology, Zebrafish, Motor, Mauthner, Dopamine, Escape
Abstract
Dopamine is a neurotransmitter involved in the control of motor coordination. Its modulation of inhibitory and excitatory processes in the motor pathways of the brain and spinal cord influences initiation and control of movement behaviors. This study examined the effects of dopamine on the physiological responses of a pair of hindbrain neurons, called the Mauthner cells, and the associated behavioral effects, in larval zebrafish. The Mauthner pair coordinate swift escape responses to sensory stimuli in zebrafish. Evidence from previous studies suggests that the Mauthner neuron receives input from dopamine neurons in the brain, and my experiments were to determine whether dopamine actually modulates Mauthner cell activity. Physiological recordings of the Mauthner and other descending neurons were done using intracellular calcium imaging, with an escape-eliciting tap stimulus applied during cell recording. The effects of bath-applied dopamine on Mauthner neuron responses were assessed by comparing responses before, during, and after dopamine treatment in the same larvae (within subjects design), and, in separate experiments, by comparing responses in dopamine treated larvae and untreated control larvae. Dopamine exposure produced increases in Mauthner calcium response magnitude and likelihood of behavioral response to stimuli. These differences were not found in the control experiments. In the context of this and previous research, dopamine appears to facilitate escape-related swimming in larvae while inhibiting spontaneous swimming activity.
Recommended Citation
Sturchio, Gabrielle, "Dopamine modulation of escape movements in larval zebrafish" (2012). Cal Poly Humboldt theses and projects. 1303.
https://digitalcommons.humboldt.edu/etd/1303
https://scholarworks.calstate.edu/concern/theses/2f75rb449