Journal of neurophysiology
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Randomized Controlled Trial Comparative Study
Leg muscle vibration modulates bodily self-consciousness: integration of proprioceptive, visual, and tactile signals.
Behavioral studies have used visuo-tactile conflicts between a participant's body and a visually presented fake or virtual body to investigate the importance of bodily perception for self-consciousness (bodily self-consciousness). Illusory self-identification with a fake body and changes in tactile processing--modulation of visuo-tactile cross-modal congruency effects (CCEs)--were reported in previous findings. Although proprioceptive signals are deemed important for bodily self-consciousness, their contribution to the representation of the full body has not been studied. ⋯ We applied vibrations at the upper limbs (which provide no information about the position of the participant's body in space) and in this case observed no modulation of bodily self-consciousness or tactile perception. These data link proprioceptive signals from the legs that are conveyed through the dorsal column-medial lemniscal pathway to bodily self-consciousness. We discuss their integration with bodily signals from vision and touch for full-body representations.
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Comparative Study
Basolateral amygdala responds robustly to social calls: spiking characteristics of single unit activity.
Vocalizations emitted within a social context can trigger call-specific changes in the emotional and physiological/autonomic state of the receiver. The amygdala is implicated in mediating these changes, but its role in call perception remains relatively unexplored. We examined call and pitch selectivity of single neurons within the basolateral amygdala (BLA) by recording spiking activity in response to 5 pitch variants of each of 14 species-specific calls presented to awake, head-restrained mustached bats, Pteronotus parnellii. ⋯ A call-wise analysis of spiking activity revealed that call types signaling either threat or fear most consistently evoked increases in the spike rate. In contrast, calls emitted during appeasement tended to evoke spike suppression. Our data suggest that BLA neurons participate in the processing of multiple call types and exhibit a rich variety of temporal response patterns that are neither neuron nor call specific.
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Comparative Study
Mesopic background lights enhance dark-adapted cone ERG flash responses in the intact mouse retina: a possible role for gap junctional decoupling.
The cone-driven flash responses of mouse electroretinogram (ERG) increase as much as twofold over the course of several minutes during adaptation to a rod-compressing background light. The origins of this phenomenon were investigated in the present work by recording preflash-isolated (M-)cone flash responses ex vivo in darkness and during application of various steady background lights. In this protocol, the cone stimulating flash was preceded by a preflash that maintains rods under saturation (hyperpolarized) to allow selective stimulation of the cones at varying background light levels. ⋯ However, applying gap junction blockers to the dark-adapted retina produced qualitatively similar changes in the cone flash responses as did background light and prevented further growth during subsequent light-adaptation. These results are consistent with the idea that cone ERG photoresponses are suppressed in the dark-adapted mouse retina by gap junctional coupling between rods and cones. This coupling would then be gradually and reversibly removed by mesopic background lights, allowing larger functional range for the cone light responses.