ItchingWIKIMEDIA COMMONS, MUHAMMAD MAHDI KARIM

1. Between itch and pain

To explain why some patients get an itch along with their pain relief when given morphine, researchers examined two variants of the morphine receptor and found they relay two signals—one that relieves pain and one that induces an itching sensation. The finding of distinct cellular pathways suggests a way to uncouple these effects.

X.Y. Liu et al., "Unidirectional Cross-Activation of GRPR by MOR1D Uncouples Itch and Analgesia Induced by Opioids," Cell, 147:447-58, 2011. Free F1000 Evaluation

2. The hunger switch

Hormones that relay hunger or satiety trigger a feedback loop in the brain that continues long after the hormones are degraded, creating a memory of hunger that may influence the success of dieters.

Y. Yang, et al., "Hunger states switch a flip-flop memory circuit via a synaptic AMPK-dependent positive feedback loop,"Cell, 146:992-1003, 2011. Free F1000 Evaluation...

3. How blind fish keep time

Cavefish that live in complete darkness follow a clock that's 47 hours long, rather than the standard 24-hour clock entrained by normal daylight cycles. Interestingly, it appears that the fish use mutant versions of two light receptors found in zebra fish to regulate the remainder of the cavefish's peripheral clocks.

N. Cavallari et al., "A blind circadian clock in cavefish reveals that opsins mediate peripheral clock photoreception," PLoS Biol, 9:e1001142, 2011. Free F1000 Evaluation

4. Melding space and time

Not only do neurons in the brain's new-memory center fire at specific locations in order to relay information about location, but they also fire at particular intervals in order to record sequential events separated by time, bringing time and space information together.

C. J. MacDonald et al., "Hippocampal "time cells" bridge the gap in memory for discontiguous events," Neuron, 71:737-49, 2011. Free F1000 Evaluation

5. Stimulated mice stay leaner

Housing mice in environments with additional stimuli, such as a running wheel, not only increases their mental health, improving memory and conferring resistance to brain damage, but also helps them stay fitter, reducing the rate of diet-induced obesity.

(Read our 2009 feature on animal enrichment, “Lab Toys.”)

L. Cao et al., "White to brown fat phenotypic switch induced by genetic and environmental activation of a hypothalamic-adipocyte axis," Cell Metab, 14:324-38, 2011. Free F1000 Evaluation

6. A rewarding new path

Researchers find a new pathway in the brain that links a memory processing center with a reward center and is likely to be important in normal learning and addiction.

A. H. Luo et al., "Linking context with reward: a functional circuit from hippocampal CA3 to ventral tegmental area," Science, 333:353-57, 2011. Free F1000 Evaluation

7. Brain-immunity missing link

Researchers have long been puzzled as to how the nerves that feed into the spleen—an organ involved in immunity—could produce the acetylcholine signals that dampen inflammation, since  spleenic cells don't make acetylcholine.  New evidence points to a T-cell population in the spleen as the culprit, responding to nerve signals and producing acetylcholine.

(Read our news story "Neurotransmitter Regulated Immunity")

M. Rosas-Ballina et al., "Acetylcholine-synthesizing T cells relay neural signals in a vagus nerve circuit," Science, 2011 Oct 7; 334(6052):98-101. Free F1000 Evaluation

The F1000 Top 7 is a snapshot of the highest ranked articles from a 14-day period on Faculty of 1000 Neuroscience, as calculated on November 3, 2011. Faculty Members evaluate and rate the most important papers in their field. To see the latest rankings, search the database, and read daily evaluations, visit http://f1000.com.

 

Interested in reading more?

Become a Member of

Receive full access to more than 35 years of archives, as well as TS Digest, digital editions of The Scientist, feature stories, and much more!
Already a member?