The use of human embryonic stem cells (hESCs) in research is of course highly controversial, raising ethical questions that for many people amount to serious dilemmas. In our April editorial we didn’t address the moral questions at all, but criticized recent efforts to discredit hESC research.

We’ve received two letters chiding us for the editorial. Though we can’t publish these letters in Nature Neuroscience, we are happy to discuss the matter on Action Potential. We invite the authors of the two letters to join us on the blog, and everyone else of course is also welcome to chip in.

Here are the links to the editorial, and the two pieces we discussed as examples for the new trick of spinning stem cell science against stem cell science. All are available for free:

Nature Neuroscience April 2007 editorial

Maureen L. Condic, “What We Know About Embryonic Stem Cells”, First Things, January 2007

The White House Domestic Policy Council, “Advancing Stem Cell Science Without Destroying Human Life”, January 2007

PKC-1 regulates secretion of neuropeptides

The atypical protein kinase C PKC-1 is required for exocytosis of dense-core neuropeptide vesicles in worm motoneurons, but it is not involved in synaptic neurotransmitter vesicle exocytosis.

Dyslexia and the failure to form a perceptual anchor

Reading appears to be primarily a visual task, but it has been proposed that children suffering from dyslexia may actually have in impairment in auditory processing. This study reports that a set of learning-disabled and dyslexic children had trouble with certain sound discrimination tasks, supporting the idea that the root of dyslexia could lie in auditory cognition.

Propagating waves mediate information transfer in the motor cortex

The authors here trained macaques to reach for a target upon command, then recorded field potential oscillations from their premotor and motor cortices. Just before the monkey made its reaching motion, the cue triggered beta waves whose phase and amplitude correlated with reaching direction.

Simple fall-off pattern of correlated neural activity in the developing lateral geniculate nucleus

Multielectrode recordings from the lateral geniculate nucleus of movie-watching young ferrets reveal an activity pattern that does not agree with theoretical predictions.

Dynorphin A activates bradykinin receptors to maintain neuropathic pain

Opioids usually alleviate pain by acting at opiate receptors, but this study now reports that the opioid dynorphin A can also activate bradykinin receptors, thereby contributing to neuropathic pain.

Cannabinoids reveal importance of spike timing coordination in hippocampal function

In vivo multi-unit recordings from rats reveal that cannabinoids desynchronize hippocampal neuron assemblies without affecting the average firing rate. The loss of synchrony correlates with cannabinoid-induced memory deficits in a hippocampus-dependent task.

This paper received quite some coverage in the popular press. Even the free rag metro NY (distributed on the subway here) covered it, with the fabulous headline “Baked neurons behind marijuana memory loss”.

(Thanks to Jan Theunissen from Nature Biotechnology for alerting me to the metro article.)

BACE1 modulates myelination in the central and peripheral nervous system

The proteinase BACE1 is part of the mechanism that releases the toxic amyloid Abeta fragment from APP, but its ‘real’ function has been enigmatic. This study reports that myelination is impaired in BACE1 null mice, and suggests that the myelination signal neuregulin-1 is a BACE1 substrate.

The P2Y12 receptor regulates microglial activation by extracellular nucleotides

This study identifies in mice a metabotropic ATP/ADP receptor that is essential for the activation of microglia in response to injury to the cortex .

In vivo time-lapse imaging shows dynamic oligodendrocyte progenitor behavior during zebrafish development

Watch oligodendrocyte precursors migrate through the zebrafish embryonic spinal cord, and orderly align themselves along the axons they are going to myelinate. Amazing videos.