國立虎尾科技大學 |

Non-linear Stimulus Integration in Olfactory Computation.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Non-linear Stimulus Integration in Olfactory Computation./
Author:	Bell, Joseph Sumner.
Description:	1 online resource (101 pages)
Notes:	Source: Dissertation Abstracts International, Volume: 77-04(E), Section: B.
Subject:	Neurosciences. -
Online resource:	click for full text (PQDT)
ISBN:	9781339291765

Non-linear Stimulus Integration in Olfactory Computation.
Bell, Joseph Sumner.

Non-linear Stimulus Integration in Olfactory Computation. - 1 online resource (101 pages)

Source: Dissertation Abstracts International, Volume: 77-04(E), Section: B.

Thesis (Ph.D.)--Harvard University, 2015.

Includes bibliographical references

All animals must use patterns of olfactory receptor neuron (ORN) activity to compute appropriate behavioral responses to odors, but the form of this computation is unknown. In both flies and mammals, each ORN expresses one type of odorant receptor that determines its odor response profile, and all ORNs expressing the same receptor project to the same compartment in the brain, or glomerulus. These glomeruli constitute parallel processing channels that relay olfactory information to other areas, and are often co-activated by odors. One popular hypothesis holds that activity in each glomerulus contributes to a central representation of valence, or pleasantness, by a fixed linear weight. Alternatively, non-linear interactions between specific glomeruli could confer increased selectivity or sensitivity for ethologically important odors. We investigate these alternative models by optogenetically activating olfactory glomeruli in freely walking Drosophila, and use video tracking to analyze the behavioral responses of thousands of individual flies. Flies respond to optogenetic fictive odors, but require wind to orient their walking responses. Some glomeruli produce robust attraction when activated individually. Combining stimulation of pairs of glomeruli produces unpredictable results: some pairs sum to produce attraction greater than that elicited by either component, but others produce the same behavior as the more attractive component alone. Surprisingly, we find no reliably repulsive glomeruli, but some potently reduce attraction in combinations. Based on which glomeruli summate, we develop a simple model that establishes a lower bound on the dimensionality of internal olfactory representations. Although we provide evidence that the brain combines signals from glomeruli using several pools with overlapping but distinct sets of inputs, detailed computational analysis of walking trajectories suggests that flies respond to these stimuli by graded recruitment of a single behavioral program.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2018

Mode of access: World Wide Web

ISBN: 9781339291765Subjects--Topical Terms:

593561
Neurosciences.
Index Terms--Genre/Form:

554714
Electronic books.

Non-linear Stimulus Integration in Olfactory Computation.
LDR:03096ntm a2200301K 4500 001 913803
005 20180622095237.5
006 m o u
007 cr mn||||a|a||
008 190606s2015 xx obm 000 0 eng d
020 $a 9781339291765
035 $a (MiAaPQ)AAI3738697
035 $a (MiAaPQ)vireo:harvard277Bell
035 $a AAI3738697
040 $a MiAaPQ $b eng $c MiAaPQ
100 1 $a Bell, Joseph Sumner. $3 1186793
245 1 0 $a Non-linear Stimulus Integration in Olfactory Computation.
264 0 $c 2015
300 $a 1 online resource (101 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Dissertation Abstracts International, Volume: 77-04(E), Section: B.
502 $a Thesis (Ph.D.)--Harvard University, 2015.
504 $a Includes bibliographical references
520 $a All animals must use patterns of olfactory receptor neuron (ORN) activity to compute appropriate behavioral responses to odors, but the form of this computation is unknown. In both flies and mammals, each ORN expresses one type of odorant receptor that determines its odor response profile, and all ORNs expressing the same receptor project to the same compartment in the brain, or glomerulus. These glomeruli constitute parallel processing channels that relay olfactory information to other areas, and are often co-activated by odors. One popular hypothesis holds that activity in each glomerulus contributes to a central representation of valence, or pleasantness, by a fixed linear weight. Alternatively, non-linear interactions between specific glomeruli could confer increased selectivity or sensitivity for ethologically important odors. We investigate these alternative models by optogenetically activating olfactory glomeruli in freely walking Drosophila, and use video tracking to analyze the behavioral responses of thousands of individual flies. Flies respond to optogenetic fictive odors, but require wind to orient their walking responses. Some glomeruli produce robust attraction when activated individually. Combining stimulation of pairs of glomeruli produces unpredictable results: some pairs sum to produce attraction greater than that elicited by either component, but others produce the same behavior as the more attractive component alone. Surprisingly, we find no reliably repulsive glomeruli, but some potently reduce attraction in combinations. Based on which glomeruli summate, we develop a simple model that establishes a lower bound on the dimensionality of internal olfactory representations. Although we provide evidence that the brain combines signals from glomeruli using several pools with overlapping but distinct sets of inputs, detailed computational analysis of walking trajectories suggests that flies respond to these stimuli by graded recruitment of a single behavioral program.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2018
538 $a Mode of access: World Wide Web
650 4 $a Neurosciences. $3 593561
655 7 $a Electronic books. $2 local $3 554714
690 $a 0317
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a Harvard University. $b Medical Sciences. $3 1186638
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3738697 $z click for full text (PQDT)