Neurologiske abnormiteter
I artiklen At the Synapse: Gene May Shed Light On Neurological Disorders får vi et indblik i hvilke årsager forskere mener at kunne finde for det man kalder neurologiske abnormiteter. Flere forskellige omstændigheder omkring graviditeten menes at kunne spille en meget central rolle; sygdomme, kemikalier, alkohol, medicin mv. Men andre omstændigheder kan også spille en central rolle og her er det fokus på at genforhold der kan gøre at nogen mennesker har større risiko for at få hvad man, groft sagt, kunne kalde en neurologisk fejl.
In our brains, where millions of signals move across a network of neurons like runners in a relay race, all the critical baton passes take place at synapses. These small gaps between nerve cell endings have to be just the right size for messages to transmit properly. Synapses that grow too large or too small are associated with motor and cognitive impairment, learning and memory difficulties, and other neurological disorders.
In a finding that sheds light on this system, researchers at the University of Wisconsin-Madison describe a gene that controls the proper development of synapses, which could help explain how the process works and why it sometimes goes wrong.
Reporting today in the journal Neuron, a team of geneticists in the College of Agricultural and Life Sciences reveal the role of a gene in fruit flies called “nervous wreck” that prevents synapses from overgrowing by damping the effects of a pro-growth signal. Mutations in a human version of “nervous wreck” have been linked to a severe genetic developmental disability, and these findings may eventually help scientists develop treatments for this and other neurological disorders.
De neurologiske abnormiteter kan selvfølgelig variere i styrke og i hvilken slags indflydelse de har på folk, men selv de mindste forhold kan have store implikationer. I en tidligere artikel, som jeg har referet til her, mente nogen at have fundet en sammenhæng mellem netop en neurologisk abnormitet og social fobi. Der var der fokus på et decideret misforhold i neurotransmittere, der er essentielle for at videreføre informationerne i hjernen . I den herværende artikel er der dog fokus på mere generelle forhold i synapserne , der er bindingsledene i kommunikationen i hjernen. Genetiske forhold menes at kunne være afgørende for om synapserne fx bliver for små eller for store.
Using genetic, biochemical and imaging techniques, O’Connor-Giles showed that the “nervous wreck” protein appears to be part of an important protein complex that helps regulate the density of certain receptors on the surface of the nerve cell at the synapse. In particular, the new findings suggest that the protein complex decommissions receptors that respond to pro-growth signals coming from the well-studied BMP signaling pathway. When the protein complex is working properly, it moves the receptors back inside the nerve cell – where they can no longer receive and respond to the pro-growth signal – at the appropriate time.
“‘Nervous wreck’ and (the other proteins in the complex) work together to attenuate a positive growth signal,” says O’Connor-Giles. “So when it’s time for synaptic growth to stop, they are the proteins that ensure the neuron stops listening to the positive growth signal and stops growing.
Undersøgelsen giver et indblik i forståelsen mellem forholdene mellem forskellige proteiner, celler og udviklingen og stabiliseringen af synapserne. Og igen er spørgsmålet om hvorvidt disse fremskridt i viden om forskellige neurologiske omstændigheder i sygdomme vil afføde behandlingsformer.
These findings add to the big picture of how synaptic growth works, a picture that in the long run will help scientists develop treatments for various neurological disorders.
“Being able to manipulate synaptic growth is going to be crucial for treating traumatic spinal chord injuries,” says O’Connor-Giles. “It’s also going to be important for treating a broad array of other disorders, including epilepsy and developmental disabilities.”
Kilde:
University of Wisconsin-Madison (2008, May 25). At The Synapse: Gene May Shed Light On Neurological Disorders. ScienceDaily. Retrieved May 25, 2008, from http://www.sciencedaily.com/releases/2008/05/080522181503.htm
Læg en kommentar