Lab Report: Research on Bird Songs and Language, biology homework help

Here is a link to a great lecture by Dr. Jarvis about his research. (See the 4th video down on the list: “Brain evolution; Lessons from birds and humans who sing and talk.” Running time: 1 hour, 17 mintues.)

These links include: another wonderful lecture by Dr. Jarvis, photomicrographs of avian brain anatomy, experimental techniques using ablation, effects of stimuli timing in development, audio and physical cues, effects of deafness on learning as well as a review of audiographs. In addition, his lab site serves as a portal for data about the genetics and evolution of birds that can sing. You will be comparing and contrasting neuroanatomy and DNA of song birds, non-singing bird species, and humans. 

Another great resources is the Xento-Canto community: http://www.xeno-canto.org/ This is a community database of bird sounds from around the world.

In addition to watching the lecture and answering self-test questions, you will prepare a lab report connected to each lecture.
 In each of these, you and your class will present lab reports based on the model organism and scientific research on the topic.

Lab Report

You must provide a link to the article itself or the .pdf along with your review. For example, this is found at Dr. Jarvis’ lab website under “publications:”

Jarvis, Erich, D. and Nottebohm, Fernando. Motor driven gene expression. Proc. Natl. Acad. Sci. USA. Vol. 94. pp. 4097–4102. April 1997.

Hypothesis: When songbirds sing, gene expression patterns in their brains will reflect this in proportion to how many songs they perform.

Model organism: Brains and behaviors of both canaries (Serinus canaria) and zebra finches (Taeniopygia guttata) were studied.

Controls: Some birds did not sing and this seemed easy to  achieve. When a human sat near them, the songbirds did not sing.

Variables: The number of songs a bird sang over a certain unit of time (e.g., 30 minutes).

Methods: After the set period of time (usually around 30 minutes), the birds were killed and their brains prepared to be studied with radioactive probe by a technique known as in situ hybridization. Detailed information on this laboratory technique is  available in two of the citations provided in the article.

Data: What I found interesting is that the brain sections were analyzed by researchers who did not know how many songs each bird had sung until after the results were recorded. In this way, even slight bias could not be introduced when counting the number of silver grains exposed per cell.

Results: The evidence of ZENK gene expression, (a sign of genes turning on, memory, learning, and brain activity), was very closely proportional to the number of songs each bird sang. See Figure 3A: birds that sang no songs, showed results with a very low background of activity, birds that sang a modest number of songs had evidence of ZENK gene expression midway between birds that sang no songs and those that sang a high number of songs.

Conclusions: There are many small experiments described n this paper. This part demonstrates that the very act of singing affects gene expression in specific areas of the bird’s brain and in proportion to the amount of songs sung.

New Questions:  Do some birds have more ZENK gene expression than others? Could more gene expression be correlated with social position or the vigor in which the song was sung?

Glossary

Make use of the college resources, good college dictionaries, and your text.

Plasticity: One definition of this word applies in the context of “synaptic plasticity” a critical concept in neurobiology. It refers to the ability of neuron connections called synapses as “malleable” and therefore capable of change. See The American Heritage dictionary.

Song system nuclei: These are collections of nerve cells that form a complex network of interactions in the bird’s brain. See Gale Encyclopedia of Medicine.

immediate early gene (e.g., ZENK): This research tool is also explained on pages 28-29 of the text (Box 2.1).  Genes such as ZENK quick acting and can signal neuron activity in specific areas of the brain. See: text page G-14.

in situ hybridization: This is another research tool described in two articles cited in this one. It is explained on pages 29-29 (Box 2.1) of the text. It is a techique that uses radioactive probes that will bind through complementary base pairing on a section of DNA or RNA. In this paper, “riblprobe” containing radioactive sulfur is used. See: text page G-14.