Behaviour 2019
Mosquito host seeking is a persistent behavior state for multimodal sensory integration
Trevor R. Sorrells, Anjali Pandey, Adriana Rosas, Leslie B. Vosshall. Rockefeller University, New York, NY, United States

Female Aedes aegypti mosquitoes undergo a specialized sequence of behaviors to locate and bite a human host. Host-seeking behavior is driven by multimodal sensory cues such as carbon dioxide, heat, and human odor, but how these cues are integrated over time is poorly understood. To answer this question, we have created optogenetic mosquito lines to activate defined populations of neurons. We found that feeding rates on heated blood were similar when mosquitoes received carbon dioxide and when they received optogenetic activation of the carbon dioxide sensory neurons. To understand how host cues are integrated over time, we presented a short optogenetic “fictive carbon dioxide” stimulus with or without a short heat stimulus. A single fictive carbon dioxide stimulus resulted in a persistent increase in flight, walking, and piercing attempts that peaked several minutes after the stimulus. This stimulus potentiated piercing behavior in response heat, as well as the decision to engorge on heated blood for more than 10 minutes. Taken together, these results suggest that host seeking is a persistent internal state that allows the integration of multimodal cues over time.