Sound azimuth selectivity of inferior collicular neurons in juvenile bats, Myotis chinensis

The directional selectivity of auditory neurons is one of the essential response properties that underlie sound localization, an important task performed by the mammalian auditory system. Here we evaluated the sound azimuth selectivity of inferior collicular neurons in juvenile bats, Myotis chinensis, at the age of 15 days under free-field stimulation conditions. Compared with those in adult bats, neurons in juvenile bats were broadly tuned to sound azimuth angles as indicated by both the type and width of the azimuth selectivity curves. Their best azimuth was distributed over a wide range and, moreover, the adult-like relationship between the best azimuth and the best frequency of these neurons was not developed. These data indicate that the directional selectivity of inferior collicular neurons, like other response properties examined previously, undergoes considerable change during postnatal maturation.