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Florida State University


DNA molecules carry information about how proteins, which determine the color of our eyes, hair, brain structure, etc., will be synthesized into genes.

By themselves, genes are not functional; they need to be expressed into functional proteins. The messenger molecule (mRNA), which carries information about the structure and function of the protein to be manufactured, plays an important role. Sensory experience can also modulate the mRNA's expression pattern; that is, rearing conditions before and immediately after birth can alter several aspects of neurodevelopment.

The pharmacological properties of CB1 are well known; however, little is known about its expression during early embryonic stages. The goal, then, is to understand the mechanisms occurring at a cellular level and establish its role.

CB1 has been found in the visual system of some vertebrates, including the salamander, rat, rhesus monkey, and the chick. Previous studies of the chick's visual system, performed by Dr. Richard Hyson and doctoral student Todd Stincic, suggested that CB1 signal transduction cooperates in its organization and development. If so, thought Honors student Breyda Ortega, then its expression is likely to change across ages. "Given the predominant change near hatching day, I hypothesized that early exposure or deprivation of light might change the natural time course of CB1 expression."

Breyda manipulated three different visual conditions—intense light, darkness, and standard incubation—in chick embryos of different ages. Then, analyzed the mRNA of the Cannabinoid Receptor 1 (CB1) protein in the isthmus pars parvocellularis (Ipc nucleus) of the optic tecta, the brain structure involved in object localization and movement detection and one of the first structures to be formed during embryonic development.

Her research "indicated that age significantly predicted CB1 levels, and there was a trend for dark-rearing conditions. Since chicks are precocial birds (able to move freely from birth, requiring little parental care), this, as well as other factors, may explain the decrease upon hatching." The resultant thesis, "CB1 Gene Expression in the Ipc Nucleus of the Developing Chick," was presented at three undergraduate research symposiums—Florida State, Clemson, and South Florida.

Next on the agenda for this future neuroscientist is to work with Dr. Thomas Houpt. Together they will conduct experiments related to magnetic fields and conditioned taste aversion. Says Breyda, "Our research may help in understanding the effects of magnets on humans and improve the quality of the MRI (Magnetic Resonance Imaging), which is used to scan brain activity."

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