首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
It may be debated whether individual neurons are "tuned" to react to only a single tastant such as salt or sugar-and ther
It may be debated whether individual neurons are "tuned" to react to only a single tastant such as salt or sugar-and ther
admin
2011-01-17
71
问题
It may be debated whether individual neurons are "tuned" to react to only a
single tastant such as salt or sugar-and therefore signal only one taste
quality-or whether the activity in a given neuron contributes to the neural
Line representation of more than one taste. Studies show that both peripheral and
(5) central gustatory neurons typically respond to more than one kind of stimulus,
and although each neuron is attuned most acutely to one tastant, it usually also
generates a reaction to others with dissimilar taste qualities. How then can the
brain represent various taste qualities if each neuron is receptive to many
different-tasting stimuli?
(10) Electrophysiological studies of gustatory sensory neurons, first performed
by Pfaffmann, demonstrated that peripheral neurons are not specifically
responsive to stimuli representing a single taste quality (which might be
symbolized by the pattern of activity across gustatory neurons because the
activity of any one cell was ambiguous) but instead record a spectrum of tastes.
(15) But in the 1970s and 1980s several scientists began to accumulate data indicating
that individual neurons are tuned maximally for one taste, and they interpreted
this as evidence that activity in a particular type of cell represented a given taste
quality—an idea they called the labeled-line hypothesis. According to this idea,
activity in neurons that experience the strongest reaction to sugar would signal
(20) "sweetness," activity in those that are most sensitive to acids would signal
"sourness", and so forth.
Smith later proved that the same cells that previous researchers had
interpreted as labeled lines actually defined the similarities and differences in
the patterns of activity across taste neurons, suggesting that the same neurons
(25) were responsible for taste-quality representation, whether they were viewed as
labeled lines or as critical parts of an across-neuron pattern. These investigators
further established that the neural distinction among stimuli of different
qualities depended on the simultaneous activation of different cell types, much
as with the function of color vision, but unlike auditory perception. These and
(30) other considerations have led us to favor the idea that the patterns of activity
are key to coding taste information.
Scientists now know that things that taste similarly evoke similar patterns
of activity across groups of taste neurons. Furthermore, we can compare these
patterns and use multivariate statistical analysis to plot the similarities in the
(35) patterns elicited by various tastants. Taste researchers have generated such
comparisons for gustatory stimuli from the neural responses of hamsters and
rats and these correspond very closely to similar plots generated in behavioral
experiments, from which we may infer which stimuli taste alike and which taste
different to animals. Such data show that the across-neuron patterns contain
(40) sufficient information for taste discrimination and this may be a reasonable
explanation for neural coding in taste, though researchers continue to debate
whether individual neuron types play a more significant role in taste coding than
they do in color vision. Scientists question whether taste is an analytic sense, in
which each quality is separate, or a synthetic sense like color vision, where
(45) combinations of colors produce a unique quality.
The author mentions the research performed on hamsters and rats most probably in order to
选项
A、demonstrate a case where the implications of the labeled-line hypothesis clearly do not hold
B、show the limits of experimental inquiry in determining the role of the individual neuron in taste
C、explain the necessity for determining the extent to which visual perception is analogous to gustatory perception
D、provide further corroboration for the predictions made by the across-pattern model of taste neurology
E、prove the salient differences between taste perception in humans and in animals
答案
D
解析
转载请注明原文地址:https://www.kaotiyun.com/show/CIjO777K
本试题收录于:
GRE VERBAL题库GRE分类
0
GRE VERBAL
GRE
相关试题推荐
Whenhereallydoessomethingwrong,heiswillingto______.
Youaretowritein100-120wordsonthetopicWhydoPeopleLike/DislikeiPhones?Youshouldbaseyourcompositionontheout
ResearchersinBritainaretellingschoolsthatchildrenshouldbedoingmorelearningoutdoors.Theresearcherssaythereiscu
Haveyoueverheardofapawpaw(木瓜)?Ifnot,donotfeelbad.ManyAmericansdonotknowofthefruit,althoughitisnativeto
Forthispart,youareallowed30minutestowriteacompositiononthetopicSocialPracticeofCollegeStudents.Youshouldwr
—Theriverrunsclear.—Weallappreciatetheimportancethelocalgovernmenthas______theenvironmentalprotection.
Advertisement:Today’scustomersexpecthighquality.Everyadvanceinthequalityofmanufacturedproductsraisescustomerexpe
DEMENTIA:DISORDER::
PHILOSOPHY:METAPHYSICS::
HypatiaofAlexandria,anotedmathematicianinRomanEgyptwhoalsotaughtphilosophyandastronomy,championed(i)______,deli
随机试题
CB—B型齿轮泵的泵体厚度一般比齿轮宽度厚()。
纤维胃镜检查适宜的体位是
霍乱引起暴发流行最为重要的传播方式是
建筑工程费用的估算可采用单位建筑工程投资估算法,此法可进一步细分为()。
下列关于会计账簿、报表的生成与管理,说法不正确的是()。
党内民主的核心是()。
设f(x)二阶连续可导,f(0)=0,f’(0)=1,且[xy(x+y)一f(x)y]dx+[f’(x)+x2y]dy=0为全微分方程,求f(x)及该全微分方程的通解.
(2012上集管)关于项目的风险管理,下列说法中,______是不正确的。
边界网关协议BGP的报文(1)传送。一个外部路由器通过发送(2)报文与另一个外部路由器建立邻居关系,如果得到应答,才能周期性地交换路由信息。(2010年上半年试题)(1)
在窗体上添加一个文本框Text1,然后编写如下的Load事件过程,则程序运行结果为()。PrivateSubForm_Load0Text1.Text=""Text1.SetFocusFork=1To
最新回复
(
0
)