1. Owls on the Prowl
Joseph F. Bergan, Peter Ro, Daniel Ro, and Eric I. Knudsen
The eyes and ears of the barn owl provide a formidable adversary for the barn mouse. To examine this elegant system, the precise alignment of topographical maps of visual and auditory space in the optic tectum can be perturbed with prism-containing goggles. Juvenile owls readily adapt their auditory maps under these conditions, but adults show much less plasticity. This week, Bergan et al. tested whether hunting live prey would enhance adult plasticity. Hunting enhanced the realignment of the auditory map as manifested by shifts in the tuning of the interaural timing difference. The live action also improved hunting performance.
2. Silencing Mutant Huntingtin Late in the Course
Miguel Díaz-Hernández, Jesús Torres- Peraza, Alejandro Salvatori-Abarca, María A. Morán, Pilar Gómez-Ramos, Jordi Alberch, and José J. Lucas
This week, Díaz-Hernández et al. try to arrest Huntington's disease (HD) late in the course by silencing mutant huntingtin (htt) in a mouse model of HD (Tet/HD94). Despite progressive loss of motor coordination, striatal atrophy, and neuronal htt-positive inclusions, the Tet/HD94 mice do not show loss of striatal neurons until 17 months of age. At this late stage, the authors treated the conditional mutant mice with doxycycline to shut off expression of the htt transgene. After five additional months, "gene-off" mice showed improved motor performance, whereas untreated "gene-on" Tet/HD94 mice continued to worsen. The authors suggest that gene silencing even at a late stage could have therapeutic potential.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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Nothing in life is to be feared. It is only to be understood.
-- Marie Curie