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Bat Echolocation. By: Sohan Warusha. What is echolocation . Bats use echolocation to navigate in dark environments Receive three dimensional images of their surrounding in complete darkness by emitting sonar signals and evaluating the returning echoes
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Bat Echolocation By: Sohan Warusha
What is echolocation • Bats use echolocation to navigate in dark environments • Receive three dimensional images of their surrounding in complete darkness by emitting sonar signals and evaluating the returning echoes • Bats produce an ultrasonic vocalization and use the returning echoes to determine the position, size and other features of the obstacle depending on the time, frequency content, duration and intensity of the returning signal. • Combination of auditory and motor system coordination leads to a successful echolocation.
Auditory Processing • Bats underwent brain surgery and three electrodes were placed in the brain to measure brain activity. • Sensory motor control mechanism of echolocating bat is controlled at the superior colliculus (SC) • first cluster of neural response would be related to the control of vocalization, including the mouth and nose actions • after generating the sonar call, bats immediately suppress sonar producing action and then start to pay close attention to the reception of the returning echo • Then bats changed ear shape and direction.
Motor production • Sonar vocalization changes due to duration, bandwidth, spectral content and temporal patterning • the researchers were able to show that parabrachial nucleus (PB) plays a role in the control of the call frequency • GABAa agonist lowered the call frequency emitted at rest • Excitation of AMPA and blocking the inhibition of BMI increased the sonar call frequency • Stimulation of bat SC leads to head and pinna movement. This also leads to the production of sonar vocalization