Postnatal subventricular zone progenitors give rise not only to granular and periglomerular interneurons but also to interneurons in the external plexiform layer of the rat olfactory bulb

2007 ◽  
Vol 506 (2) ◽  
pp. 347-358 ◽  
Author(s):  
Zhengang Yang
Keyword(s):  
Olfactory Bulb ◽  
Subventricular Zone ◽  
Plexiform Layer

The Mitral and Short Axon Cells of the Olfactory Bulb

1970 ◽  
Vol 7 (3) ◽  
pp. 631-651
Author(s):  
J. L. PRICE ◽  
T. P. S. POWELL
Keyword(s):  
Electron Microscope ◽  
Olfactory Bulb ◽  
Granule Cells ◽  
Primary Dendrite ◽  
Plexiform Layer ◽  
Mitral Cell ◽  
Granule Cell Layer ◽  
Mitral Cells ◽  
Axon Initial Segments ◽  
Large Neurons

A description is given of the mitral and short axon cells of the olfactory bulb of the rat from Golgi material examined with the light microscope and from material examined with the electron microscope. The mitral cells are large neurons with primary and secondary dendrites which both extend into the overlying external plexiform layer, although only the primary dendrite enters the glomerular formations. No predominant antero-posterior orientation of the secondary dendrites has been found. Within the glomeruli the mitral cell dendrites are in synaptic contact with the olfactory nerves and also with the periglomerular cells, but elsewhere the only synapses on the mitral cells are the ‘reciprocal synapses’ with the granule cells. Synaptic-type vesicles are found in all parts of the mitral cells, including the axon initial segments; they appear to be especially concentrated in the distal portions of the dendrites. Several types of short axon cells have been found in the granule cell layer in Golgi-impregnated material. Their cell bodies can also be distinguished with the electron microscope, and from previous work it is probable that the axons of at least some of these cells form flattened-vesicle symmetrical synapses upon the granule cells.

Spatiotemporal selectivity of response to Notch1 signals in mammalian forebrain precursors

Development ◽  
2001 ◽  
Vol 128 (5) ◽  
pp. 689-702 ◽  
Author(s):  
C.B. Chambers ◽  
Y. Peng ◽  
H. Nguyen ◽  
N. Gaiano ◽  
G. Fishell ◽  
...  
Keyword(s):  
Olfactory Bulb ◽  
Cell Fate ◽  
Subventricular Zone ◽  
Cellular Proliferation ◽  
Precursor Cells ◽  
Temporal Cues ◽  
Short And Long Term ◽  
Cortical Regions ◽  
Anterior Subventricular Zone

The olfactory bulb, neocortex and archicortex arise from a common pool of progenitors in the dorsal telencephalon. We studied the consequences of supplying excess Notch1 signal in vivo on the cellular and regional destinies of telencephalic precursors using bicistronic replication defective retroviruses. After ventricular injections mid-neurogenesis (E14.5), activated Notch1 retrovirus markedly inhibited the generation of neurons from telencephalic precursors, delayed the emergence of cells from the subventricular zone (SVZ), and produced an augmentation of glial progeny in the neo- and archicortex. However, activated Notch1 had a distinct effect on the progenitors of the olfactory bulb, markedly reducing the numbers of cells of any type that migrated there. To elucidate the mechanism of the cell fate changes elicited by Notch1 signals in the cortical regions, short- and long-term cultures of E14.5 telencephalic progenitors were examined. These studies reveal that activated Notch1 elicits a cessation of proliferation that coincides with an inhibition of the generation of neurons. Later, during gliogenesis, activated Notch1 triggers a rapid cellular proliferation with a significant increase in the generation of cells expressing GFAP. To examine the generation of cells destined for the olfactory bulb, we used stereotaxic injections into the early postnatal anterior subventricular zone (SVZa). We observed that precursors of the olfactory bulb responded to Notch signals by remaining quiescent and failing to give rise to differentiated progeny of any type, unlike cortical precursor cells, which generated glia instead of neurons. These data show that forebrain precursors vary in their response to Notch signals according to spatial and temporal cues, and that Notch signals influence the composition of forebrain regions by modulating the rate of proliferation of neural precursor cells.

Olfactory bulb responses to odor stimulation: analysis of response pattern and intensity relationships

1986 ◽  
Vol 56 (6) ◽  
pp. 1571-1589 ◽  
Author(s):  
T. A. Harrison ◽  
J. W. Scott
Keyword(s):  
Olfactory Bulb ◽  
Stimulus Intensity ◽  
Plexiform Layer ◽  
Response Assessment ◽  
Spike Trains ◽  
Response Magnitude ◽  
Response Form ◽  
Stimulus Response ◽  
Response Profiles ◽  
Inhibitory Components

Extracellular recordings were made from mitral cells, tufted cells, and presumed glomerular layer and external plexiform layer interneurons of the olfactory bulb of anesthetized rats during odor stimulation. Intensity responses of these cells were studied by presenting a series of six or seven concentrations, spanning a range greater than two log units, in a cyclic artificial sniff paradigm, which produced repeated response measures at each concentration. Experiments focused on obtaining a complete intensity series, including interspersed unstimulated spontaneous activity records, for a single odorant (usually amyl acetate), but concentration responses to other odorants were tested when possible. Odor responses of 46 cells were studied with two approaches. Response form was examined in an attempt to define response classes based on qualitative characteristics of the temporal pattern of response. Assessment of response magnitude was attempted, in order to construct stimulus-response functions for each cell, independent of response form. As previously reported for olfactory bulb cells, the cells in our sample responded to odor stimulation with spike trains of a variety of temporal patterns, consisting of excitatory and inhibitory components that were frequently recognizable in the responses of a cell across a range of concentrations. However, response patterns usually changed significantly with concentration, such that response form across the concentration range could not be predicted from the response at any one concentration. Responses of different cells were sometimes similar to each other in form at one concentration and quite different from each other in the rest of their concentration-response profiles. Classification of response profiles into discrete types, based on consistency of response form throughout the profile, was therefore not feasible. In agreement with other reports, response of a single cell to different odorants sometimes showed similar forms and sometimes showed very different forms across the concentration-response profiles. Since the response form depends on the stimulus intensity as well as the stimulus quality, characterization of response magnitude and of the pattern of response to different odors require testing with a series of stimulus concentrations. Because odor responses consisted of temporally patterned spike trains, whose components changed in complex ways with stimulus intensity, it was not possible to quantify response magnitude by measuring characteristics of particular response components or counting mean frequency.(ABSTRACT TRUNCATED AT 400 WORDS)

Olfactory bulb potentials evoked by electrical stimulation of the contralateral bulb

1959 ◽  
Vol 196 (2) ◽  
pp. 327-329 ◽  
Author(s):  
Raymond R. Walsh
Keyword(s):  
Electrical Stimulation ◽  
Olfactory Bulb ◽  
Short Duration ◽  
Evoked Potential ◽  
Plexiform Layer ◽  
Electrical Stimulus ◽  
Tetanic Stimulation ◽  
Granular Cells ◽  
Postsynaptic Potential ◽  
Stimulation Of

A single, short-duration electrical stimulus delivered to one olfactory bulb evokes a potential in the contralateral bulb. As recorded with a unipolar electrode, the potential is negative central to, and positive peripheral to the external plexiform layer. Bipolar recordings from multiple sites show that the potential is not actively propagated. The potential summates in response to tetanic stimulation and is blocked by anoxia and dimethyl ether d-tubocurarine. In addition to confirming the existence of an interolfactory bulb system, the electrophysiological evidence in conjunction with known anatomical relationships strongly suggests that the evoked potential is a postsynaptic potential of the internal granular cells.

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 > sTC > 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.

scholarly journals IGF-I promotes neuronal migration and positioning in the olfactory bulb and the exit of neuroblasts from the subventricular zone

2009 ◽  
Vol 30 (5) ◽  
pp. 742-755 ◽  
Author(s):  
Anahí Hurtado-Chong ◽  
María J. Yusta-Boyo ◽  
Eva Vergaño-Vera ◽  
Alessandro Bulfone ◽  
Flora de Pablo ◽  
...  
Keyword(s):  
Olfactory Bulb ◽  
Subventricular Zone ◽  
Neuronal Migration ◽  
Igf I

scholarly journals Multifaceted actions of Zeb2 in postnatal neurogenesis from the ventricular-subventricular zone to the olfactory bulb

Development ◽  
2020 ◽  
Vol 147 (10) ◽  
pp. dev184861
Author(s):  
Astrid Deryckere ◽  
Elke Stappers ◽  
Ruben Dries ◽  
Elise Peyre ◽  
Veronique van den Berghe ◽  
...  
Keyword(s):  
Olfactory Bulb ◽  
Subventricular Zone ◽  
Postnatal Neurogenesis
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