Dendritic Ca(2+) dynamics and multimodal processing in a cricket antennal interneuron

The integration of stimuli of different modalities is fundamental to information processing within the nervous system. A descending interneuron in the cricket brain, with prominent dendrites in the deutocerebrum, receives input from three sensory modalities: touch of the antennal flagellum, strain of the antennal base, and visual stimulation. Using calcium imaging, we demonstrate that each modality drives a Ca(2+) increase in a different dendritic region. Moreover, touch of the flagellum is represented in a topographic map along the neuron’s dendrites. Using intracellular recording, we investigated the effects of Ca(2+) on spike shape through the application of the Ca(2+) channel antagonist Cd(2+) and identified probable Ca(2+)-dependent K(+) currents. NEW & NOTEWORTHY Different dendritic regions of the cricket brain neuron DBNi1-2 showed localized Ca(2+) increases when three modalities of stimulation (touch of the flagellum, strain at antennal base, and visual input) were given. Touch stimulation induces localized Ca(2+) increases according to a topographic map of the antenna. Ca(2+) appears to activate K(+) currents in DBNi1-2.