1. Tracking Down Anomalous L Channels
Alexandra Koschak, Gerald J. Obermair, Francesca Pivotto, Martina J. Sinnegger-Brauns, Jrg Striessnig, and Daniela Pietrobon
In this week's Journal, Koschak et al. identify Cav1.2 as the pore-forming subunit of anomalous L-type calcium channels in neurons, a subclass of L-type channels that show long reopenings at negative voltages after a strong depolarization. These channels coexist with conventional L-type channels in rat cerebellar granule cells as well as other neurons. The authors found by quantitative reverse transcription-PCR that the bulk of L-type calcium channel transcripts in granule cells encoded Cav1.2 subunits, whereas the remainder encoded Cav1.3. Single-channel recording from granule cells in Cav1.3-/- mice revealed normal amounts of both gating types. In Cav1.2DHP-/- mice, which express mutant Cav1.2 channels that are insensitive to dihydropyridines (DHPs), the long reopenings in neurons treated with DHP were similar to anomalous currents in wild-type neurons and shorter than typical DHP-induced long openings. The authors suggest that the anomalous openings may drive L-type channel-dependent gene transcription in long-lasting plasticity.
2. An Interhemispheric Effect on Whisker Plasticity
Stanislaw Glazewski, Brett L. Benedetti, and Alison L. Barth
Glazewski et al. did some fancy whisker trimming in mice to examine experience-dependent plasticity in barrel cortex. In rodents, whisker deflection excites neurons in the contralateral somatosensory cortex, whereas concurrent stimulation of ipsilateral whiskers is inhibitory. The authors recorded responses in single neurons in barrel cortex after deflection of contralateral whiskers. Mice deprived of ipsilateral whiskers for 1 week had increased cortical receptive fields to contralateral whisker stimulation. Next, the mi
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Contact: Sara Harris
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Society for Neuroscience
3-Apr-2007