News tips from the Journal of Neuroscience

December 12, 2006

1. With and without the 3 Mints
Angela Ho, Wade Morishita, Deniz Atasoy, Xinran Liu, Katsuhiko Tabuchi, Robert E. Hammer, Robert C. Malenka, and Thomas C. Südhof

You can tell a lot about a protein by what it hangs out with. The three Mints (also called X11-like proteins) bind to multiple synaptic proteins, and knock-out studies have suggested that they may indeed be necessary in synaptic transmission. But different isoforms can complement each other's function; thus, it has been difficult to come to firm conclusions using single knock-outs. This week, Ho et al. deleted the Mints using constitutive and conditional knock-out strategies. Deletion of Mint 1 and 2, the two isoforms specifically expressed in neurons, caused most mice to die at birth. The 20% that survived had ataxia and reduced body weight. In the double knock-outs, whole-cell recording of hippocampal neurons revealed lowered synaptic strength, a twofold decrease in the frequency of miniature EPSCs, and enhanced paired-pulse facilitation, indicative of a presynaptic action of Mint 1 and 2. Similar results were obtained with acute ablation of Mint 1/2/3.

2. Born-Again Neurons in Mice and Men
John J. Ohab, Sheila Fleming, Armin Blesch, and S. Thomas Carmichael and Jadranka Macas, Christian Nern, Karl H. Plate, and Stefan Momma

Stroke doesn't only cause cell death, but it also attempts at recovery through neuronal regeneration in tissues near the infarct, according to two separate studies published this week. Using histological analyses in a large collection of postmortem human brains, Macas et al. found increased numbers of neuronal precursor cells, even in patients of advanced age who had suffered ischemia. Because recent studies have coupled neurogenesis to the formation of new blood vessels, Ohab et al. tested the link in a model of focal stroke in mice. These authors showed that stroke induced the long-distance migration of thousands of newly born neuroblasts from the subventricular zone to peri-infarct cortex. The new cells associated with peri-infarct blood vessels in a region of active vascular remodeling. When Ohab et al. added stromal-derived factor 1 and angiopoietin 1, which are produced by the vasculature, the number of newly formed neurons increased.

3. Localizing Vocal Emotions
Jane E. Warren, Disa A. Sauter, Frank Eisner, Jade Wiland, M. Alexander Dresner, Richard J. S. Wise, Stuart Rosen, and Sophie K. Scott

The sound of laughter or cheering typically makes us smile or laugh. Warren et al. wanted to know how this happens. A facial expression showing an emotion can produce a so-called "mirror" response or similar facial expression in an observer. The authors used functional magnetic resonance imaging to determine whether similar mirror responses were also triggered by vocal expressions of emotion. Study participants were asked to listen to human voices conveying positive valence such as amusement and triumph. Listening to these "positive-valence" vocalizations activated specific premotor areas in the left posterior inferior frontal region, an area involved in control of facial movement. The activation was not attributable to facial movement per se. Thus, listening to vocal expressions of emotions appears to automatically engage preparation for orofacial gestures corresponding to the emotional content of the stimulus.

4. Ginkgo biloba and Oligomeric Aß in Worms
Yanjue Wu, Zhixin Wu, Peter Butko, Yves Christen, Mary P. Lambert, William L. Klein, Christopher D. Link, and Yuan Luo

Ginkgo biloba, the ancient plant that fed dinosaurs, is widely used in patients with Alzheimer's disease AD). This week, Wu et al. examined the effects of a standard preparation of plant extract, EGb 761, in Caenorhabditis elegans. Nematodes do not express endogenous ß amyloid (Aß), the peptide that oligomerizes and form deposits in AD brains. Nonetheless, transgenic expression of Aß causes striking pathology in C. elegans, such as muscle paralysis and problems with chemotaxis, which were alleviated by EGb 761. Rescue of these behaviors was accompanied by a reduction in Aß oligomers. The beneficial effects of G. biloba are thought to result from neuroprotective and antioxidant properties. But in the transgenic C. elegans, reducing oxidative stress with the antioxidant L-ascorbic acid was not nearly as effective in suppressing paralysis as EGb 761. Thus, the beneficial effects of the extract may result from block of Aß oligomerization.

Society for Neuroscience

Related Neurons Articles from Brightsurf:

Paying attention to the neurons behind our alertness
The neurons of layer 6 - the deepest layer of the cortex - were examined by researchers from the Okinawa Institute of Science and Technology Graduate University to uncover how they react to sensory stimulation in different behavioral states.

Trying to listen to the signal from neurons
Toyohashi University of Technology has developed a coaxial cable-inspired needle-electrode.

A mechanical way to stimulate neurons
Magnetic nanodiscs can be activated by an external magnetic field, providing a research tool for studying neural responses.

Extraordinary regeneration of neurons in zebrafish
Biologists from the University of Bayreuth have discovered a uniquely rapid form of regeneration in injured neurons and their function in the central nervous system of zebrafish.

Dopamine neurons mull over your options
Researchers at the University of Tsukuba have found that dopamine neurons in the brain can represent the decision-making process when making economic choices.

Neurons thrive even when malnourished
When animal, insect or human embryos grow in a malnourished environment, their developing nervous systems get first pick of any available nutrients so that new neurons can be made.

The first 3D map of the heart's neurons
An interdisciplinary research team establishes a new technological pipeline to build a 3D map of the neurons in the heart, revealing foundational insight into their role in heart attacks and other cardiac conditions.

Mapping the neurons of the rat heart in 3D
A team of researchers has developed a virtual 3D heart, digitally showcasing the heart's unique network of neurons for the first time.

How to put neurons into cages
Football-shaped microscale cages have been created using special laser technologies.

A molecule that directs neurons
A research team coordinated by the University of Trento studied a mass of brain cells, the habenula, linked to disorders like autism, schizophrenia and depression.

Read More: Neurons News and Neurons Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to