Response similarity to odors in olfactory bulb output cells presumed to be connected to the same glomerulus: electrophysiological study using simultaneous single-unit recordings

1990 ◽  
Vol 63 (3) ◽  
pp. 447-454 ◽  
Author(s):  
N. Buonviso ◽  
M. A. Chaput
Keyword(s):  
T Cells ◽  
Olfactory Bulb ◽  
Single Unit ◽  
Receptor Cell ◽  
Primary Dendrite ◽  
Electrophysiological Study ◽  
Adult Rats ◽  
Response Profile ◽  
Response Profiles ◽  
Single Unit Recordings

1. The glomeruli of the olfactory bulb are discrete anatomic structures in which the terminals of receptor cell axons make extensive contacts with the primary dendrites of the mitral and tufted output cells. In mammals, each mitral and deep tufted (M/T) cell possesses a single primary dendrite and sends it toward the glomerulus situated just in front of its somata. 2. We tested the hypothesis that the glomeruli, which appear to form anatomic units, could act to some extent as functional units. A unitary functioning implies that the M/T cells connected to the same glomerulus will more often display similar responses to odorants than cells having no common glomerular relationships, including cells related to adjacent glomeruli. 3. In anesthetized adult rats, we recorded the extracellular single-unit responses of pairs of M/T cells to a series of five odorants. Recordings were performed with the use of twin microelectrodes whose tips were separated either by less than 40 or by 150-200 microns. Because of the olfactory bulb organization, we assumed that the close cells, recorded at a distance less than 40 microns, were more often connected to the same glomerulus, whereas the distant cells, recorded at a distance of 150-200 microns, were more often connected to adjacent glomeruli. 4. Stimulus-evoked changes in firing rate were classified as either excitatory (+), suppressive (-), or null (0) responses. The collection of response types of a given cell to the 5 odorants composed its response profile. Response profiles were used to compare the responsiveness within close and within distant cell pairs with that observed within control pairs of cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Temporal pattern analyses in pairs of neighboring mitral cells

1992 ◽  
Vol 68 (2) ◽  
pp. 417-424 ◽  
Author(s):  
N. Buonviso ◽  
M. A. Chaput ◽  
F. Berthommier
Keyword(s):  
Temporal Pattern ◽  
Single Unit ◽  
Temporal Correlation ◽  
Maximal Activity ◽  
Similar Response ◽  
Mitral Cells ◽  
Adult Rats ◽  
Similar Activity ◽  
Activity Types ◽  
Response Profiles

1. Neighboring mitral cells in the rat olfactory bulb have been previously shown to give similar response profiles to a series of odorants. We now analyze their temporal patterns of activity before and during stimulation to evaluate to what extent soma proximity may act on their temporal correlation and to what extent olfactory stimulation may force two close cells to fire with similar patterns. 2. In anesthetized adult rats, we recorded simultaneously the extracellular single-unit activities of two mitral cells with the use of twin micropipettes with tips separated by less than 40 microns. These activities were recorded before and during stimulation by a series of five odorants. 3. Activities were classified into nine types according to their temporal pattern along the respiratory cycle. These types comprised nonrhythmic patterns and rhythmic ones, the latter being simple or complex. A phase parameter was also calculated to compare the positions of maximal activity within respiratory cycles of pairs of cells that had rhythmic activities. 4. All analyses were made by comparing data from pairs of close cells with data from pairs of control cells obtained by pairing each first cell of all recorded pairs with the second units of all other pairs. Results reveal a probability of similar activity types significantly higher in pairs of close cells than in control ones before stimulation. Odorant stimulation enhances this difference by reducing the probability of similar associations in control pairs. Close cells present similar patterns as frequently before, as during, stimulation; however, the probability of double nonrhythmic firings decreases whereas the probability of double rhythmic ones increases.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Electrophysiological evidence for a topographical projection of the nasal mucosa onto the olfactory bulb of the frog.

1976 ◽  
Vol 68 (3) ◽  
pp. 297-312 ◽  
Author(s):  
R M Costanzo ◽  
M M Mozell
Keyword(s):  
Olfactory Bulb ◽  
Olfactory Receptor ◽  
Single Unit ◽  
Rana Catesbeiana ◽  
Olfactory Nerve ◽  
The Other ◽  
Lateral Region ◽  
Electrophysiological Evidence ◽  
Response Profile ◽  
Stimulation Of

Three olfactory nerve branches respectively subserving either a medial, an intermediate, or a lateral region of the dorsal olfactory receptor sheet of the bullfrog Rana catesbeiana were electrically stimulated with bipolar platinum hook electrodes. Extracellular single unit responses from 93 second-order cells in different regions of the olfactory bulb were recorded with metal-filled glass micropipets. The excitatory responsiveness of each unit to the stimulation of each of the three nerve branches (response profile) was determined. Some units were sensitive to stimulation of each of the three nerve branches, thus suggesting a wide projection from the entire receptor sheet. On the other hand, other units were more selective. Of this latter group, units in the lateral bulb were excited by nerve branches subserving the more lateral regions of the receptor sheet; units in the medial bulb were excited by the nerve branches subserving the more medial regions of the receptor sheet. These data provide electrophysiological evidence for a topographical projection of the olfactory receptor sheet onto the olfactory bulb, and further suggest that the projections onto different bulbar cells vary in degree of localization.

Sources of the Scalp-Recorded Amplitude-Modulation Following Response

2002 ◽  
Vol 13 (04) ◽  
pp. 188-204 ◽  
Author(s):  
Shigeyuki Kuwada ◽  
Julia S. Anderson ◽  
Ranjan Batra ◽  
Douglas C. Fitzpatrick ◽  
Natacha Teissier ◽  
...  
Keyword(s):  
Animal Model ◽  
Amplitude Modulation ◽  
Single Unit ◽  
Modulation Frequency ◽  
Multiple Sources ◽  
High Modulation ◽  
Before And After ◽  
Single Unit Recordings ◽  
Composite Response ◽  
The Brain

The scalp-recorded amplitude-modulation following response (AMFR)” is gaining recognition as an objective audiometric tool, but little is known about the neural sources that underlie this potential. We hypothesized, based on our human studies and single-unit recordings in animals, that the scalp-recorded AMFR reflects the interaction of multiple sources. We tested this hypothesis using an animal model, the unanesthetized rabbit. We compared AMFRs recorded from the surface of the brain at different locations and before and after the administration of agents likely to enhance or suppress neural generators. We also recorded AMFRs locally at several stations along the auditory neuraxis. We conclude that the surface-recorded AMFR is indeed a composite response from multiple brain generators. Although the response at any modulation frequency can reflect the activity of more than one generator, the AMFRs to low and high modulation frequencies appear to reflect a strong contribution from cortical and subcortical sources, respectively.

scholarly journals Duplicate Detection of Spike Events: A Relevant Problem in Human Single-Unit Recordings

2021 ◽  
Vol 11 (6) ◽  
pp. 761
Author(s):  
Gert Dehnen ◽  
Marcel S. Kehl ◽  
Alana Darcher ◽  
Tamara T. Müller ◽  
Jakob H. Macke ◽  
...  
Keyword(s):  
Data Quality ◽  
Single Unit ◽  
Human Subjects ◽  
External Noise ◽  
Hospital Environment ◽  
Noise Sources ◽  
Recording Channels ◽  
Waveform Similarity ◽  
Therapeutic Procedures ◽  
Single Unit Recordings

Single-unit recordings in the brain of behaving human subjects provide a unique opportunity to advance our understanding of neural mechanisms of cognition. These recordings are exclusively performed in medical centers during diagnostic or therapeutic procedures. The presence of medical instruments along with other aspects of the hospital environment limit the control of electrical noise compared to animal laboratory environments. Here, we highlight the problem of an increased occurrence of simultaneous spike events on different recording channels in human single-unit recordings. Most of these simultaneous events were detected in clusters previously labeled as artifacts and showed similar waveforms. These events may result from common external noise sources or from different micro-electrodes recording activity from the same neuron. To address the problem of duplicate recorded events, we introduce an open-source algorithm to identify these artificial spike events based on their synchronicity and waveform similarity. Applying our method to a comprehensive dataset of human single-unit recordings, we demonstrate that our algorithm can substantially increase the data quality of these recordings. Given our findings, we argue that future studies of single-unit activity recorded under noisy conditions should employ algorithms of this kind to improve data quality.

A device enabling single unit recordings during head movements in cats

1982 ◽  
Vol 8 (4) ◽  
pp. 443-444 ◽  
Author(s):  
J.S. Schneider ◽  
A.A. Castaldi ◽  
T.I. Lidsky
Keyword(s):  
Single Unit ◽  
Head Movements ◽  
Single Unit Recordings

scholarly journals Responses of thalamic neurons to itch- and pain-producing stimuli in rats

2018 ◽  
Vol 120 (3) ◽  
pp. 1119-1134 ◽  
Author(s):  
Brett Lipshetz ◽  
Sergey G. Khasabov ◽  
Hai Truong ◽  
Theoden I. Netoff ◽  
Donald A. Simone ◽  
...  
Keyword(s):  
Single Unit ◽  
Electrophysiological Study ◽  
Receptive Fields ◽  
The Body ◽  
Cell Column ◽  
Thalamic Neurons ◽  
Medial Nucleus ◽  
Anesthetized Rats ◽  
Transmission Of Information ◽  
Posterior Medial Nucleus

Understanding of processing and transmission of information related to itch and pain in the thalamus is incomplete. In fact, no single unit studies of pruriceptive transmission in the thalamus have yet appeared. In urethane-anesthetized rats, we examined responses of 66 thalamic neurons to itch- and pain- inducing stimuli including chloroquine, serotonin, β-alanine, histamine, and capsaicin. Eighty percent of all cells were activated by intradermal injections of one or more pruritogens. Forty percent of tested neurons responded to injection of three, four, or even five agents. Almost half of the examined neurons had mechanically defined receptive fields that extended onto distant areas of the body. Pruriceptive neurons were located within what appeared to be a continuous cell column extending from the posterior triangular nucleus (PoT) caudally to the ventral posterior medial nucleus (VPM) rostrally. All neurons tested within PoT were found to be pruriceptive. In addition, neurons in this nucleus responded at higher frequencies than did those in VPM, an indication that PoT might prove to be a particularly interesting region for additional studies of itch transmission. NEW & NOTEWORTHY Processing of information related to itch within in the thalamus is not well understood, We show in this, the first single-unit electrophysiological study of responses of thalamic neurons to pruritogens, that itch-responsive neurons are concentrated in two nuclei within the rat thalamus, the posterior triangular, and the ventral posterior medial nuclei.

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.

Single-unit recordings of arterial chemoreceptors from mouse petrosal ganglia in vitro

2000 ◽  
Vol 88 (4) ◽  
pp. 1489-1495 ◽  
Author(s):  
David F. Donnelly ◽  
Ricardo Rigual
Keyword(s):  
Mouse Model ◽  
Carotid Body ◽  
Unit Activity ◽  
Action Potentials ◽  
Single Unit ◽  
Gene Deletions ◽  
Suction Electrode ◽  
Single Unit Recordings ◽  
Unit Action

A preparation was developed that allows for the recording of single-unit chemoreceptor activity from mouse carotid body in vitro. An anesthetized mouse was decapitated, and each carotid body was harvested, along with the sinus nerve, glossopharyngeal nerve, and petrosal ganglia. After exposure to collagenase/trypsin, the cleaned complex was transferred to a recording chamber where it was superfused with oxygenated saline. The ganglia was searched for evoked or spontaneous unit activity by using a glass suction electrode. Single-unit action potentials were 57 ± 10 (SE) ( n = 16) standard deviations above the recording noise, and spontaneous spikes were generated as a random process. Decreasing superfusate[Formula: see text] to near 20 Torr caused an increase in spiking activity from 1.3 ± 0.4 to 14.1 ± 1.9 Hz ( n = 16). The use of mice for chemoreceptor studies may be advantageous because targeted gene deletions are well developed in the mouse model and may be useful in addressing unresolved questions regarding the mechanism of chemotransduction.

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