Nature neuroscience
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Nature neuroscience · Apr 2010
Comparative StudyA fast rod photoreceptor signaling pathway in the mammalian retina.
Rod photoreceptors were recently shown to contact 'Off' cone bipolar cells, providing an alternative pathway for rod signal flow in the mammalian retina. By recording from pairs of rods and Off cone bipolar cells in the ground squirrel (Spermophilus tridecemlineatus), we measured the synaptic responses of mammalian rods unfiltered by the slow kinetics of the rod bipolar cell response. We show that vesicle fusion and turnover in mammalian rods is fast, and that this new pathway can mediate rapid signaling.
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Nature neuroscience · Apr 2010
Comparative StudyObservational fear learning involves affective pain system and Cav1.2 Ca2+ channels in ACC.
Fear can be acquired vicariously through social observation of others suffering from aversive stimuli. We found that mice (observers) developed freezing behavior by observing other mice (demonstrators) receive repetitive foot shocks. Observers had higher fear responses when demonstrators were socially related to themselves, such as siblings or mating partners. ⋯ The ACC neuronal activities were increased and synchronized with those of the lateral amygdala at theta rhythm frequency during this learning. Furthermore, an ACC-limited deletion of Ca(v)1.2 Ca(2+) channels in mice impaired observational fear learning and reduced behavioral pain responses. These results demonstrate the functional involvement of the affective pain system and Ca(v)1.2 channels of the ACC in observational social fear.