Parallel Tufted Cell and Mitral Cell Pathways from the Olfactory Bulb to the Olfactory Cortex

2014 ◽  
pp. 133-160 ◽  
Author(s):  
Shin Nagayama ◽  
Kei M. Igarashi ◽  
Hiroyuki Manabe ◽  
Kensaku Mori
2020 ◽  
Author(s):  
Sara Zeppilli ◽  
Tobias Ackels ◽  
Robin Attey ◽  
Nell Klimpert ◽  
Kimberly D. Ritola ◽  
...  

AbstractProjection neurons (PNs) in the mammalian olfactory bulb (OB) receive direct input from the nose and project to diverse cortical and subcortical areas. Morphological and physiological studies have highlighted functional heterogeneity, yet no molecular markers have been described that delineate PN subtypes. Here, we used viral injections into olfactory cortex and fluorescent nucleus sorting to enrich PNs for high-throughput single nucleus and bulk RNA deep sequencing. Transcriptome analysis and RNA in situ hybridization identified three mitral and five tufted cell populations with characteristic transcription factor network topology and cell adhesion and excitability-related gene expression. Finally, by integrating bulk and snRNA-seq data we propose that different mitral cell populations selectively project to different regions of olfactory cortex. Together, we have identified potential molecular and gene regulatory mechanisms underlying PN diversity and provide new molecular entry points into studying the diverse functional roles of mitral and tufted cell subtypes.


2021 ◽  
pp. 851-861
Author(s):  
Kelly D. Flemming

This chapter briefly repeats key anatomic characteristics and then reviews clinical disorders affecting each cranial nerve in addition to the brainstem. More specifically, this chapter covers cranial nerves I, V, VII, and IX through XII plus the brainstem. The olfactory nerve is a special visceral afferent nerve that functions in the sense of smell. The axons of the olfactory receptor cells within the nasal cavity extend through the cribriform plate to the olfactory bulb. These olfactory receptor cell axons synapse with mitral cells in the olfactory bulb. Mitral cell axons project to the primary olfactory cortex and amygdala. The olfactory cortex interconnects with various autonomic and visceral centers.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Sara Zeppilli ◽  
Tobias Ackels ◽  
Robin Attey ◽  
Nell Klimpert ◽  
Dr. Kimberly Ritola ◽  
...  

Projection neurons (PNs) in the mammalian olfactory bulb (OB) receive input from the nose and project to diverse cortical and subcortical areas. Morphological and physiological studies have highlighted functional heterogeneity, yet no molecular markers have been described that delineate PN subtypes. Here, we used viral injections into olfactory cortex and fluorescent nucleus sorting to enrich PNs for high-throughput single nucleus and bulk RNA deep sequencing. Transcriptome analysis and RNA in situ hybridization identified distinct mitral and tufted cell populations with characteristic transcription factor network topology, cell adhesion and excitability-related gene expression. Finally, we describe a new computational approach for integrating bulk and snRNA-seq data, and provide evidence that different mitral cell populations preferentially project to different target regions. Together, we have identified potential molecular and gene regulatory mechanisms underlying PN diversity and provide new molecular entry points into studying the diverse functional roles of mitral and tufted cell subtypes.


1980 ◽  
Vol 28 (11) ◽  
pp. 1157-1169 ◽  
Author(s):  
D A Godfrey ◽  
C D Ross ◽  
J A Carter ◽  
O H Lowry ◽  
F M Matschinsky

Levels of the proposed neurotransmitter amino acids glutamate, aspartate, gamma-aminobutyric acid (GABA), and glycine were measured within the layered structures of the olfactory bulb and olfactory cortex following unilateral transections of the lateral olfactory tract or of virtually all fiber tracts of the olfactory peduncle. Distributions of the amino acids on both lesion and control sides were examined and compared by means of a mapping procedure. The results suggest: 1) Glutamate and aspartate are specifically associated with mitral (and presumably also tufted) cell axons and terminals in the piriform cortex. The distribution of aspartate in the olfactory bulb is further suggestive of a specific association of aspartate with mitral cell dendrites and somata. 2) Glutamate might be specifically associated with some centrifugal fibers traveling to the olfactory bulb in or near the anterior commissure. 3) GABA might be specifically related to some certrifugal fibers to the olfactory bulb in addition to its prominent association with granule cells of the bulb. 4) Glycine is unlikely to play a prominent neurotransmitter role in either the olfactory bulb or olfactory cortex.


2007 ◽  
Vol 97 (4) ◽  
pp. 3136-3141 ◽  
Author(s):  
Thomas Heinbockel ◽  
Kathryn A. Hamilton ◽  
Matthew Ennis

In the main olfactory bulb, several populations of granule cells (GCs) can be distinguished based on the soma location either superficially, interspersed with mitral cells within the mitral cell layer (MCL), or deeper, within the GC layer (GCL). Little is known about the physiological properties of superficial GCs (sGCs) versus deep GCs (dGCs). Here, we used patch-clamp recording methods to explore the role of Group I metabotropic glutamate receptors (mGluRs) in regulating the activity of GCs in slices from wildtype and mGluR−/− mutant mice. In wildtype mice, bath application of the selective Group I mGluR agonist DHPG depolarized and increased the firing rate of both GC subtypes. In the presence of blockers of fast synaptic transmission (APV, CNQX, gabazine), DHPG directly depolarized both GC subtypes, although the two GC subtypes responded differentially to DHPG in mGluR1−/− and mGluR5−/− mice. DHPG depolarized sGCs in slices from mGluR5−/− mice, although it had no effect on sGCs in slices from mGluR1−/− mice. By contrast, DHPG depolarized dGCs in slices from mGluR1−/− mice but had no effect on dGCs in slices from mGluR5−/− mice. Previous studies showed that mitral cells express mGluR1 but not mGluR5. The present results therefore suggest that sGCs are more similar to mitral cells than dGCs in terms of mGluR expression.


iScience ◽  
2021 ◽  
pp. 102946
Author(s):  
Cheng Ly ◽  
Andrea K. Barreiro ◽  
Shree Hari Gautam ◽  
Woodrow L. Shew
Keyword(s):  

1970 ◽  
Vol 7 (3) ◽  
pp. 631-651
Author(s):  
J. L. PRICE ◽  
T. P. S. POWELL

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.


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