These data indicate that gabaergic inhibition makes an important contribution to the direction - dependent frequency tuning of most ic neurons . corticofugal modulation of the excitatory and inhibitory ftcs of most ic neurons was more pronounced at one sound direction than the other . sound direction effects on frequency tuning characteristics may undergo a postnatal development due to the development of excitation and inhibition integration 通过对幼年(出生后第四周)和成年蝙蝠下丘听神经元频率调谐的方向敏感性的比较，发现幼年蝙蝠频率调谐的方向敏感性比成年蝙蝠差，并认为可能是动物发育过程中，下丘的兴奋性和抑制性输入的整合也有一个发育的过程。
