【摘要】 研究了菲菊头蝠自由飞行状态下的回声定位信号和下丘神经元的声反应特性。菲菊头蝠在自由飞行时发射的CF/FM型回声定位叫声含2-3个谐波,主频为105.3±1.7kHz,时程为39.5±9.6ms,脉冲间隔为73.9±16.0ms。在所记录到的159个下丘神经元中,E型(Echolocation)神经元为32.7%(52/159),其中CF1型(Constantfrequency)占11.3%(18/159),FM1型(Frequencymodulated)占20.1%(32/159),FM2型占1.3%(2/159);NE型(Nonecholocation)神经元的比例为67.3%(107/159)。这些神经元的最佳频率(Bestfrequency,BF)与记录深度之间存在线性关系(r=0.9471,P<0.01)。E型神经元的深度范围为349-1855(1027.5±351.6)μm,阈值范围为6-74(43.1±14.5)dBSPL,潜伏期范围为10.0-26.0(14.6±3.8)ms。NE型神经元的分别为93.0-1745.0(733.3±290.3)μm、2-70(36.5±23.8)dBSPL、5.0-23.0(13.5±3.7)ms。记录到的53个IC神经元的调谐曲线(Frequencytuningcurve,FTC)均为开放型,51个为单峰型,2个为双峰型。单峰型神经元中大部分为狭窄型(Q10dB>5),占70.6%(36/51),E型神经元全部为狭窄型,Q10dB为10.4±7.1(5.5-31.6),其中CF1型为18.3±11.2(5.5-31.6),FM1型为8.7±4.7(5.5-24.3),FM2型为6.9±0.3(6.7-7.1);NE型神经元既有宽阔型也有狭窄型,Q10dB为6.6±5.1(1.6-25.6)。两个双峰型FTC主、副峰分别偏向高、低频区,高频边对应的是E型神经元。更多还原

【Abstract】 We studied the echolocation calls and acoustic response properties in the inferior colliculus of the least horseshoe bat Rhinolophus pusillus.Bats emitted CF/FM (constant frequency/frequency modulated) pulses with 2-3 harmonics.The peak frequency,pulse duration,interpulse interval of the calls were 105.3±1.7 kHz,39.5±9.6 ms,73.9±16.0 ms,respectively.In the 159 recorded neurons,the percentage of E (echolocation) neurons whose best frequencies (BFs) were corresponding to the first and second harmonics of the signals were 32.7% (52/159) among which CF1 neurons were 11.3%(18/159),FM1 were 20.1%(32/159) and FM2 were 1.3%(2/159),respectively.BFs were correlated with the recording depths and the E neurons were distributed between 349- 1 855( 1 027.5±351.6) μm the minimum threshold (MT),latencies were 6-74 (43.1±14.5) dB SPL,10.0-26.0 (14.6±3.8) ms respectively.The types of 53 recorded frequency tuning curves (FTCs) including 51 single peaked neurons and 2 double peaked neurons were all V-shaped and most of which were narrow types (70.6%,36/51; Q 10-dB>5).E neurons were all narrow types and the Q 10-dB of CF1,FM1 and FM2 neurons were 18.3±11.2,8.7±4.7 and 6.9±0.3,respectively.NE (non-echolocation) neurons were either wide or narrow types and the Q 10-dB was 6.6±5.1 which was lower than E neurons.The BFs of the two neurons with double peaks were corresponding to the frequency range of low frequency area and high frequency area including E neurons’.更多还原