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.
Which of the following laboratory results, if found, would be LEAST consistent with the author’s explanation of the neurophysiology of taste?
选项
A、A group of taste neurons is found which only responds to sweet taste when stimulated by sweet foods.
B、A brain-wave analysis of a rat genetically engineered to lack a sense of sweet tastes is nevertheless found to have a sense of sour tastes.
C、Most tastes are found to have strikingly different neurological effects on humans they do upon animals.
D、A brain-wave analysis of a hamster demonstrates a similar pattern of activity in a given neurological area for both sour and sweet stimuli.
E、A group of taste neurons is found which provides insufficient information for taste discrimination.
答案
A
解析
转载请注明原文地址:https://kaotiyun.com/show/DIjO777K
本试题收录于:
GRE VERBAL题库GRE分类
0
GRE VERBAL
GRE
相关试题推荐
Itisagoodideaforparentstomonitorthe______aswellasthekindoftelevisionthattheirchildrenwatch.
JohnSmith,adiligentstudent,neverrefusesto______moreresponsibilitiesthatareassignedtohim.
Scientistsmeasuredtheimpactthatpeoplehaveontheenviromentusingatermcalledcarbon"footprint".Thatfootprintreflect
Theheavystormyesterdaysettherecordfortheheaviestrainfall______inasingleday.
Today,peopleliveinaworld______newtechnologyistakinganincreasingproportionintheirlives.
Scientistssaidtheyhavefoundevidenceofagiantplanetfaroutinoursolarsystem.Inastatement,theCaliforniaInstitute
Scientistssaidtheyhavefoundevidenceofagiantplanetfaroutinoursolarsystem.Inastatement,theCaliforniaInstitute
Humanbehaviorismostlyaproductoflearning,______thebehaviorofanimalsdependsmainlyoninstinct.
LOGS:WOODPILE::
Theprofessor’shabitualairof_________wasamisleadingfront,concealingamazingreservesofpatienceandadeepcommitment
随机试题
王甲离异多年,生前立下遗嘱,自己的3万元积蓄死后由其侄王乙所有。王甲去世后,王乙将这3万元钱捐给了一家慈善机构。王甲前妻得知此事,认为王乙无权继承,要求他归还3万元钱。对此,下列理解正确的是()。
DBMS为用户查询选择一个合适的执行策略的过程称为查询优化。()
Doctorssayangercanbeanextremelydamagingemotionunlessyoulearnhowto【C1】______withit.Theywarnthatangryhostilefe
患者,女性,65岁,CO中毒已昏迷1小时,面色苍白,呼吸减慢,心率102次/分。急诊人院。对此患者的治疗应为
2016年4月,甲啤酒生产企业向其关联企业(增值税一般纳税人)的啤酒销售公司销售啤酒2吨,共计取得不含税销售收入5800元,另收取期限为两个月的包装物押金234元,同月,该啤酒销售公司将2吨啤酒销售,取得含税销售收入9360元,则甲啤酒生产企业当月应缴纳消
教师工作对象千差万别,这就要求教师要不断学习,不断反思,这说明教师是教学活动的()。
贝多芬曾多次______地对小卡尔进行批评劝诫,但他的仁慈和宽容没有唤回毫无人性的小卡尔。填入划横线部分最恰当的一项是()
下面把顾问分配到各个活动的方案哪一种是可以接受的?下面哪一对顾问可以被一块派去指导网球?
设总体X的分布律为(θ为正参数),一1,2,一1,1,2为样本观察值,则θ的极大似然估计值为________.
Theworldisgoingthroughthebiggestwaveofmergersandacquisitionseverwitnessed.TheprocesssweepsfromhyperactiveAmer
最新回复
(
0
)