Odor representation and discrimination in mitral/tufted cells of the rat olfactory bulb

1996 ◽  
Vol 112 (1) ◽  
Author(s):  
Fumiaki Motokizawa
Keyword(s):  
Olfactory Bulb ◽  
Tufted Cells ◽  
Odor Representation

scholarly journals Active sampling state dynamically enhances olfactory bulb odor representation

2017 ◽  
Author(s):  
Rebecca Jordan ◽  
Izumi Fukunaga ◽  
Mihaly Kollo ◽  
Andreas T. Schaefer
Keyword(s):  
Olfactory Bulb ◽  
Mitral Cell ◽  
Active Sampling ◽  
Cell Type Specificity ◽  
Contextual Modulation ◽  
Crucial Component ◽  
Tufted Cells ◽  
Mechanistic Basis ◽  
Highly Correlated ◽  
Odor Representation

SummaryThe olfactory bulb (OB) is the very first site of odor information processing, yet a wealth of contextual and learned information has been described in its activity. To investigate the mechanistic basis of contextual modulation, we use whole-cell recordings to measure odor responses across rapid (<30 min) learning episodes in identified mitral/tufted cells (MTCs). Across these learning episodes, we found that diverse response changes occur already during the first sniff cycle. Motivated mice develop active sniffing strategies across learning, and it is this change of active sampling state that dynamically modulates odor responses, resulting in enhanced discriminability and detectability of odor representation with learning. Evoking fast sniffing in different behavioral states demonstrates that response changes during active sampling exceed those predicted from purely feed-forward input. Finally, response changes are highly correlated in tufted cells, but not mitral cells, indicating cell-type specificity in the effect of active sampling, and resulting in increased odor detectability in the tufted and enhanced discriminability in the mitral cell population over the rapid learning episodes. Altogether, we show that active sampling state is a crucial component in modulating and enhancing olfactory bulb responsiveness on rapid timescales.

Mitral and Tufted Cells Differ in the Decoding Manner of Odor Maps in the Rat Olfactory Bulb

2004 ◽  
Vol 91 (6) ◽  
pp. 2532-2540 ◽  
Author(s):  
Shin Nagayama ◽  
Yuji K. Takahashi ◽  
Yoshihiro Yoshihara ◽  
Kensaku Mori
Keyword(s):  
Olfactory Bulb ◽  
Spike Activity ◽  
Homologous Series ◽  
Morphological Difference ◽  
Aliphatic Acid ◽  
Mitral Cells ◽  
Firing Rates ◽  
Aliphatic Acids ◽  
Projection Pattern ◽  
Tufted Cells

Mitral and tufted cells in the mammalian olfactory bulb are principal neurons, each type having distinct projection pattern of their dendrites and axons. The morphological difference suggests that mitral and tufted cells are functionally distinct and may process different aspects of olfactory information. To examine this possibility, we recorded odorant-evoked spike responses from mitral and middle tufted cells in the aliphatic acid- and aldehyde-responsive cluster at the dorsomedial part of the rat olfactory bulb. Homologous series of aliphatic acids and aldehydes were used for odorant stimulation. In response to adequate odorants, mitral cells showed spike responses with relatively low firing rates, whereas middle tufted cells responded with higher firing rates. Examination of the molecular receptive range (MRR) indicated that most mitral cells exhibited a robust inhibitory MRR, whereas a majority of middle tufted cells showed no or only a weak inhibitory MRR. In addition, structurally different odorants that activated neighboring clusters inhibited the spike activity of mitral cells, whereas they caused no or only a weak inhibition in the middle tufted cells. Furthermore, responses of mitral cells to an adequate excitatory odorant were greatly inhibited by mixing the odorant with other odorants that activated neighboring glomeruli. In contrast, odorants that activated neighboring glomeruli did not significantly inhibit the responses of middle tufted cells to the adequate excitatory odorant. These results indicate a clear difference between mitral and middle tufted cells in the manner of decoding the glomerular odor maps.

scholarly journals Interglomerular Lateral Inhibition Targeted on External Tufted Cells in the Olfactory Bulb

2013 ◽  
Vol 33 (4) ◽  
pp. 1552-1563 ◽  
Author(s):  
J. D. Whitesell ◽  
K. A. Sorensen ◽  
B. C. Jarvie ◽  
S. T. Hentges ◽  
N. E. Schoppa
Keyword(s):  
Olfactory Bulb ◽  
Lateral Inhibition ◽  
Tufted Cells

scholarly journals External Tufted Cells Drive the Output of Olfactory Bulb Glomeruli

2009 ◽  
Vol 29 (7) ◽  
pp. 2043-2052 ◽  
Author(s):  
D. De Saint Jan ◽  
D. Hirnet ◽  
G. L. Westbrook ◽  
S. Charpak
Keyword(s):  
Olfactory Bulb ◽  
Tufted Cells

scholarly journals Active Sampling State Dynamically Enhances Olfactory Bulb Odor Representation

Neuron ◽  
2018 ◽  
Vol 98 (6) ◽  
pp. 1214-1228.e5 ◽  
Author(s):  
Rebecca Jordan ◽  
Izumi Fukunaga ◽  
Mihaly Kollo ◽  
Andreas T. Schaefer
Keyword(s):  
Olfactory Bulb ◽  
Active Sampling ◽  
Odor Representation

scholarly journals Cellular and Synaptic Mechanisms That Differentiate Mitral Cells and Superficial Tufted Cells Into Parallel Output Channels in the Olfactory Bulb

2020 ◽  
Vol 14 ◽  
Author(s):  
Shelly Jones ◽  
Joel Zylberberg ◽  
Nathan Schoppa
Keyword(s):  
Olfactory Bulb ◽  
Plexiform Layer ◽  
Input Resistance ◽  
Cell Types ◽  
Mitral Cells ◽  
Whole Cell ◽  
Wide Range ◽  
Tufted Cells ◽  
Parallel Output

A common feature of the primary processing structures of sensory systems is the presence of parallel output “channels” that convey different information about a stimulus. In the mammalian olfactory bulb, this is reflected in the mitral cells (MCs) and tufted cells (TCs) that have differing sensitivities to odors, with TCs being more sensitive than MCs. In this study, we examined potential mechanisms underlying the different responses of MCs vs. TCs. For TCs, we focused on superficial TCs (sTCs), which are a population of output TCs that reside in the superficial-most portion of the external plexiform layer, along with external tufted cells (eTCs), which are glutamatergic interneurons in the glomerular layer. Using whole-cell patch-clamp recordings in mouse bulb slices, we first measured excitatory currents in MCs, sTCs, and eTCs following olfactory sensory neuron (OSN) stimulation, separating the responses into a fast, monosynaptic component reflecting direct inputs from OSNs and a prolonged component partially reflecting eTC-mediated feedforward excitation. Responses were measured to a wide range of OSN stimulation intensities, simulating the different levels of OSN activity that would be expected to be produced by varying odor concentrations in vivo. Over a range of stimulation intensities, we found that the monosynaptic current varied significantly between the cell types, in the order of eTC &gt; sTC &gt; MC. The prolonged component was smaller in sTCs vs. both MCs and eTCs. sTCs also had much higher whole-cell input resistances than MCs, reflecting their smaller size and greater membrane resistivity. To evaluate how these different electrophysiological aspects contributed to spiking of the output MCs and sTCs, we used computational modeling. By exchanging the different cell properties in our modeled MCs and sTCs, we could evaluate each property's contribution to spiking differences between these cell types. This analysis suggested that the higher sensitivity of spiking in sTCs vs. MCs reflected both their larger monosynaptic OSN signal as well as their higher input resistance, while their smaller prolonged currents had a modest opposing effect. Taken together, our results indicate that both synaptic and intrinsic cellular features contribute to the production of parallel output channels in the olfactory bulb.

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