Featured Research

from universities, journals, and other organizations

Fruitfly study identifies brain circuit that drives daily cycles of rest, activity

Date:
April 24, 2014
Source:
Perelman School of Medicine at the University of Pennsylvania
Summary:
Researchers describe a circuit in the brain of fruit flies that controls their daily, rhythmic behavior of rest and activity. They also found that the fly version of the human brain protein known as corticotrophin releasing factor is a major coordinating molecule in this circuit.

This image shows a model of the circadian output circuit for locomotor rhythms. One hemisphere of the fly brain is depicted. The circuit extends from the master pacemaker cells called s-LNvs (red), through other cells called DN1s (orange), and on to different types of pars intercerebralis cells (blue), which modulate locomotor rhythms through the release of the molecule DH44.
Credit: Daniel Cavanaugh, Perelman School of Medicine, University of Pennsylvania

Amita Sehgal, PhD, a professor of Neuroscience at the Perelman School of Medicine, University of Pennsylvania, describes in Cell a circuit in the brain of fruit flies that controls their daily, rhythmic behavior of rest and activity. The new study also found that the fly version of the human brain protein known as corticotrophin releasing factor (CRF) is a major coordinating molecule in this circuit. Fly CRF, called DH44, is required for rest/activity cycles and is produced in cells that receive input from the clock cells in the fly brain. In mammals, CRF is secreted rhythmically and it drives the expression of glucocorticoids such as cortisol and is associated with stress and anxiety.

Animal models like flies are helping to fill gaps in current knowledge about how the brain works, notes Sehgal. Indeed, she says, the Brain Research through Advancing Innovative Neurotechnologies (BRAIN), initiative, a project of the National Institutes of Health, includes the study of simple animal models, which are expected to provide more detailed insight into brain function.

Though much is known about the cellular and molecular components of the clock, the connections that link clock cells to overt behaviors, such as rest/activity behavior, have not been identified. "This study is essentially a map-of-the-circuitry experiment," says Sehgal, who is also an investigator with the Howard Hughes Medical Institute (HHMI). Like humans, flies are active during the day -- walking, flying, feeding and mating -- and spend most of the night asleep.

"We conducted a screen for circadian-relevant neurons in the fly brain and found that cells of the pars intercerebralis -- the fly version of the mammalian hypothalamus -- comprise an important component of the circadian output pathway for rest/activity rhythms in flies," Sehgal says. The mammalian hypothalamus is a neuroendocrine structure that regulates sleep, circadian rhythms, feeding and, metabolism.

The Penn team did a random targeting of cells, activating neuronal firing with a transgene designed for this purpose, to see which cells are important in the rest/active behavior. They found that cells in the pars intercerebralis (PI) are essential for rhythmic behavior, and PI cells are connected to the clock cells through a circuit of at least two synapses.

Molecular profiling of PI cells identified the fly version of DH44 as a circadian molecule that is specifically expressed by PI neurons and required for normal rest/activity rhythms in flies. And, when the scientists selectively activated or removed just six PI cells positive for DH44, the fly's activity cycles became irregular. In other words, the flies no longer restricted their sleep to the dark and their activity to the light, but instead showed more random distribution of these behaviors

Coauthors are Daniel J. Cavanaugh, Jill D. Geratowski, Julian R. A. Wooltorton, Jennifer M. Spaethling, Xiangzhong Zheng, and James H. Eberwine, all from Penn, and Clare E. Hector and Erik C. Johnson, from Wake Forest University.

This research as funded in part by the National Institute of Neurological Disorders and Stroke (2R01NS048471) and HHMI.


Story Source:

The above story is based on materials provided by Perelman School of Medicine at the University of Pennsylvania. Note: Materials may be edited for content and length.


Journal Reference:

  1. DanielJ. Cavanaugh, JillD. Geratowski, JulianR.A. Wooltorton, JenniferM. Spaethling, ClareE. Hector, Xiangzhong Zheng, ErikC. Johnson, JamesH. Eberwine, Amita Sehgal. Identification of a Circadian Output Circuit for Rest:Activity Rhythms in Drosophila. Cell, 2014; 157 (3): 689 DOI: 10.1016/j.cell.2014.02.024

Cite This Page:

Perelman School of Medicine at the University of Pennsylvania. "Fruitfly study identifies brain circuit that drives daily cycles of rest, activity." ScienceDaily. ScienceDaily, 24 April 2014. <www.sciencedaily.com/releases/2014/04/140424124654.htm>.
Perelman School of Medicine at the University of Pennsylvania. (2014, April 24). Fruitfly study identifies brain circuit that drives daily cycles of rest, activity. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/2014/04/140424124654.htm
Perelman School of Medicine at the University of Pennsylvania. "Fruitfly study identifies brain circuit that drives daily cycles of rest, activity." ScienceDaily. www.sciencedaily.com/releases/2014/04/140424124654.htm (accessed September 20, 2014).

Share This



More Plants & Animals News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com
Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins