謝菲爾德大學(xué)的T.Prescott教授帶領(lǐng)他的研究團(tuán)隊(duì),，利用高速數(shù)碼攝像儀與自動(dòng)追蹤系統(tǒng),，對(duì)老鼠如何前后左右快速移動(dòng)胡須進(jìn)行了研究。老鼠通過擺動(dòng)胡須能夠感知周圍環(huán)境的變化,，確定物體的位置,、形狀和材質(zhì)，從而建立環(huán)境信息網(wǎng)絡(luò),，以作出快速反應(yīng)。研究團(tuán)隊(duì)通過將老鼠與其遠(yuǎn)親有袋類（marsupial）進(jìn)行對(duì)比后發(fā)現(xiàn),，可移動(dòng)胡須的出現(xiàn)是爬行動(dòng)物進(jìn)化為哺乳動(dòng)物道路上重要的,、具有里程碑意義的變化。
當(dāng)沿著直線行動(dòng)時(shí),，老鼠前后擺動(dòng)胡須的次數(shù)是相同的,，當(dāng)移動(dòng)方向行動(dòng)時(shí)，它們?cè)谵D(zhuǎn)彎側(cè)的胡須擺動(dòng)更加迅速,。當(dāng)它們的頭部某一邊接觸到物體時(shí),，另一邊的胡須就開始加速運(yùn)轉(zhuǎn)以獲取更多的信息，并對(duì)物體做出反應(yīng),。
在最近的研究中,，研究團(tuán)隊(duì)發(fā)現(xiàn)這些嚙齒動(dòng)物所使用的感觀策略同樣能夠在南美一些小型有袋類中見到，比如家短尾負(fù)鼠（grey short-tailed opossum）,。這種動(dòng)物在地球上存在超過了1.25億年,，與早期哺乳類有諸多共同點(diǎn)，它們?cè)谶M(jìn)化樹上早早便與嚙齒類分枝了,。這表明一些早期哺乳類也可能擁有能夠擺動(dòng)的胡須,，可移動(dòng)胡須的出現(xiàn)是哺乳動(dòng)物進(jìn)化的關(guān)鍵步驟。早期哺乳動(dòng)物行夜間,、樹棲生活,，因此，為了成功地在黑暗中生存,，它們的感覺器官必定極為高效,，包括視覺、聽覺,、嗅覺和觸覺,，可移動(dòng)胡須的出現(xiàn)為它們提供了新型觸覺感知方式，讓它們?cè)诤诎抵猩罡颖憷?/p>
除了繼續(xù)研究嚙齒類與有袋類之間的異同,，研究團(tuán)隊(duì)還打算利用仿生學(xué)原理研制“長(zhǎng)”有胡須的仿制機(jī)器人,，這種機(jī)器人能在沒有視覺的情況下導(dǎo)航，在災(zāi)難搜尋與營(yíng)救方面必能大展身手,。Tony說(shuō),，可移動(dòng)胡須與其他關(guān)鍵性狀,，比如溫血、胎生,、大腦容量等一樣,，是哺乳動(dòng)物進(jìn)化歷程中的關(guān)鍵節(jié)點(diǎn)，雖然現(xiàn)代人類不再擁有它,。(生物谷 Bioon.com)
doi:10.1098/rstb.2011.0156
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Active vibrissal sensing in rodents and marsupials
Ben Mitchinson, Robyn A. Grant, Kendra Arkley, Vladan Rankov, Igor Perkon and Tony J. Prescott
In rats, the long facial whiskers (mystacial macrovibrissae) are repetitively and rapidly swept back and forth during exploration in a behaviour known as ‘whisking’. In this paper, we summarize previous evidence from rats, and present new data for rat, mouse and the marsupial grey short-tailed opossum (Monodelphis domestica) showing that whisking in all three species is actively controlled both with respect to movement of the animal's body and relative to environmental structure. Using automatic whisker tracking, and Fourier analysis, we first show that the whisking motion of the mystacial vibrissae, in the horizontal plane, can be approximated as a blend of two sinusoids at the fundamental frequency (mean 8.5, 11.3 and 7.3 Hz in rat, mouse and opossum, respectively) and its second harmonic. The oscillation at the second harmonic is particularly strong in mouse (around 22 Hz) consistent with previous reports of fast whisking in that species. In all three species, we found evidence of asymmetric whisking during head turning and following unilateral object contacts consistent with active control of whisker movement. We propose that the presence of active vibrissal touch in both rodents and marsupials suggests that this behavioural capacity emerged at an early stage in the evolution of therian mammals.
