, 2011).

The successful application of a viral, minimal promoter approach is exemplified in the Ibrutinib present study and creates novel opportunities to investigate the OT system in rats and potentially across mammalian species (Knobloch et al., 2012). In mice, combining cell-specific Cre-recombinase strains and viral delivery of loxP-flanked constructs for opsins presents an alternative approach. Taken together with previous findings from the same group and others (Viviani et al., 2011 and Ciocchi et al., 2010), the findings of the present study suggest the existence of distinct routes by which fear signals flow through the central amygdala. This signals use previously unknown, spatially overlapping but nonetheless functionally segregated neuronal networks that underlie different components of the fear response, e.g., behavioral versus autonomic or active

versus passive fear expression. These microcircuits consist of neurons characterized by distinct expression of marker proteins such as neuromodulators or their receptors, which in turn directly impact on cellular function and subsequent circuit output. We now have the possibility of genetically targeting and interfering with selected circuit elements to not only characterize anatomy and connectivity, but also to investigate their specific function (Haubensak et al., 2010 and Letzkus et al., 2011) and thus to dissect neuronal circuitry

underlying complex behavior with unprecedented precision. “
“The gaze shifts we make four or five times per second are crucial to our exploration of a visual find protocol scene. They somehow succeed in repeatedly and accurately repositioning the eyes so that the most acute region of each retina (the fovea) acquires the target of greatest interest. For foveate animals like us, this is where visually guided behavior begins; that is, with the selection of a peripheral visual stimulus for further visual processing. One refers to this behavior as the overt orienting of visual attention because the selection of the target culminates in an observable movement of the see more eyes (or the eyes and the head) to acquire a specific target. Thus, for example, before crossing the street we might shift our gaze to a car moving toward us while ignoring another car moving away from us, the gaze shift being exclusively driven by velocity of the target car. This example depicts the more mundane, or one might say pedestrian, form of visual attention. However, this is not the type of attention most often studied by those who seek to identify its neural basis. The type of attention typically studied by neurophysiologists is the kind devoid of changes in gaze, namely covert attention, in which the only measurable effects on behavior are perceptual. As several 19th-century scientists (e.g.