Organization of primary afferent and local-circuit synapses in the olfactory glomerulus

1994 ◽  
Vol 52 ◽  
pp. 148-149
Author(s):  
Charles A. Greer ◽  
Juan C. Bartolomei ◽  
Jeffrey M. Dembner
Keyword(s):  
Olfactory Receptor ◽  
Room Temperature ◽  
Olfactory Nerve ◽  
Sprague Dawley ◽  
Primary Afferent ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
Olfactory Glomerulus ◽  
Sprague Dawley Rats ◽  
Confocal And Electron Microscopy

Odorant molecules are transduced by olfactory receptor cells whose axons join to form the olfactory nerve which distributes across the surface of the olfactory bulb (OB). Axons exit the nerve layer to terminate within the glomerular neuropil of the OB. While there appears a gross topography between the epithelium and OB4, it is clear that extensive topographic reorganization of axons occurs within the olfactory nerve. To better understand the mechanisms that may contribute to the establishment of glomerular-specific fascicles and functional domains within the OB, we have investigated axonal organization within the nerve and the intraglomerular distribution of primary afferent synapses using light, confocal and electron microscopy.Sprague-Dawley rats, 30 to 50 days postnatal, were anesthetized, lightly perfused with 0.9% NaCl and the OBs removed. Crystals of the lipophilic dye, Dil, were inserted into the olfactory nerve layer and the tissue placed in 4% paraformaldehyde at room temperature for 10 - 30 days.

Disorders of the Cranial Nerves and Brainstem

2021 ◽  
pp. 851-861
Author(s):  
Kelly D. Flemming
Keyword(s):  
Olfactory Bulb ◽  
Olfactory Receptor ◽  
Cranial Nerves ◽  
Olfactory Nerve ◽  
Mitral Cell ◽  
Olfactory Cortex ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
Clinical Disorders ◽  
Primary Olfactory Cortex

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.

Ultrastructural aspects of olfactory signal transduction and its development

1994 ◽  
Vol 52 ◽  
pp. 142-143
Author(s):  
Bert Ph. M. Menco
Keyword(s):  
Signal Transduction ◽  
Olfactory Receptor ◽  
Receptor Cell ◽  
Freeze Substitution ◽  
Luminal Surface ◽  
Tissue Sections ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
Olfactory Signal ◽  
Odor Molecule

Vertebrate olfactory receptor cells are specialized neurons that have numerous long tapering cilia. The distal parts of these cilia line the interface between the external odorous environment and the luminal surface of the olfactory epithelium. The length and number of these cilia results in a large surface area that presumably increases the chance that an odor molecule will meet a receptor cell. Advanced methods of cryoprepration and immuno-gold labeling were particularly useful to preserve the delicate ultrastructural and immunocytochemical features of olfactory cilia required for localization of molecules involved in olfactory signal-transduction. We subjected olfactory tissues to freeze-substitution in acetone (unfixed tissues) or methanol (fixed tissues) followed by low temperature embedding in Lowicryl K11M for that purpose. Tissue sections were immunoreacted with several antibodies against proteins that are presumably important in olfactory signal-transduction.

Presynaptic Afferent Inhibition of Lobster Olfactory Receptor Cells: Reduced Action-Potential Propagation Into Axon Terminals

1998 ◽  
Vol 80 (2) ◽  
pp. 1011-1015 ◽  
Author(s):  
Matt Wachowiak ◽  
Lawrence B. Cohen
Keyword(s):  
Action Potential ◽  
Olfactory Receptor ◽  
Receptor Cell ◽  
Action Potential Propagation ◽  
Cell Axon ◽  
Axon Terminals ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
Afferent Inhibition ◽  
Reduced Action

Wachowiak, Matt and Lawrence B. Cohen. Presynaptic afferent inhibition of lobster olfactory receptor cells: reduced action-potential propagation into axon terminals. J. Neurophysiol. 80: 1011–1015, 1998. Action-potential propagation into the axon terminals of olfactory receptor cells was measured with the use of voltage-sensitive dye imaging in the isolated spiny lobster brain. Conditioning shocks to the olfactory nerve, known to cause long-lasting suppression of olfactory lobe neurons, allowed the selective imaging of activity in receptor cell axon terminals. In normal saline the optical signal from axon terminals evoked by a test stimulus was brief (40 ms) and small in amplitude. In the presence of low-Ca2+/high-Mg2+ saline designed to reduce synaptic transmission, the test response was unchanged in time course but increased significantly in amplitude (57 ± 16%, means ± SE). This increase suggests that propagation into receptor cell axon terminals is normally suppressed after a conditioning shock; this suppression is presumably synaptically mediated. Thus our results show that presynaptic inhibition occurs at the first synapse in the olfactory pathway and that the inhibition is mediated, at least in part, via suppression of action-potential propagation into the presynaptic terminal.

Histamine-induced modulation of olfactory receptor neurones in two species of lobster, Panulirus argus and Homarus americanus

1989 ◽  
Vol 145 (1) ◽  
pp. 133-146 ◽  
Author(s):  
T. A. Bayer ◽  
T. S. McClintock ◽  
U. Grunert ◽  
B. W. Ache
Keyword(s):  
Receptor Antagonist ◽  
Olfactory Receptor ◽  
Single Cells ◽  
Homarus Americanus ◽  
Chloride Ions ◽  
Electrophysiological Recording ◽  
Stimulus Response ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
The One

In two species of lobster, application of the biogenic amine, histamine (HA), to the soma of olfactory receptor cells suppressed both spontaneous and odour-evoked activity, as shown by electrophysiological recording from single cells. The action of HA was graded, reversible, specific to HA, and had a threshold between 0.1 and 1 mumol l-1. HA increased the conductance of the membrane, primarily to chloride ions. The vertebrate HA receptor antagonist, cimetidine, and the nicotinic receptor antagonist, d-tubocurarine, but not other known vertebrate HA receptor antagonists, reversibly blocked the action of HA. These results suggest that a histaminergic mechanism modulates stimulus-response coupling in lobster olfactory receptor cells and potentially implicate a novel HA receptor, pharmacologically similar to the one recently described in the visual system of flies.

Responses of olfactory receptor cells of spiny lobsters to binary mixtures. II. Pattern mixture interactions

1991 ◽  
Vol 66 (1) ◽  
pp. 131-139 ◽  
Author(s):  
C. D. Derby ◽  
M. N. Girardot ◽  
P. C. Daniel
Keyword(s):  
Binary Mixtures ◽  
Olfactory Receptor ◽  
Neural Coding ◽  
Spiny Lobster ◽  
Neuronal Population ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
Spiny Lobsters ◽  
Mixture Interactions

1. The effect of mixture interactions in individual olfactory receptor cells of the spiny lobster on neural coding of odorant quality of binary mixtures and their components is examined in this paper. Extracellular responses of 98 olfactory receptor cells in the antennules of spiny lobsters to seven compounds [adenosine-5'-monophosphate (AMP), betaine (Bet), L-cysteine (Cys), L-glutamate (Glu), ammonium chloride (NH4), DL-succinate (Suc), taurine (Tau)] and their binary mixtures were recorded, and mixture interactions in individual olfactory receptor cells were identified. 2. Coding of odorant quality was evaluated by examining across neuron patterns (ANPs)--the relative response magnitudes across neuronal populations. ANPs are a feature of the neuronal population response and are a possible concentration-independent code of odorant quality in this system, as indicated by previous studies and present results. 3. For most binary mixtures the diversity of types and degrees of mixture interactions across the individual cells of a population of cells resulted in ANPs for each mixture to be different from the ANPs for the components of the mixture and different from the ANP predicted for the mixture from the responses to the components (Figs. 2–10). These effects are called pattern mixture interactions (PMIs). PMIs occurred for most binary mixtures, even those that did not produce statistically significant intensity mixture interactions (IMIs) for this same population of cells. 4. The results suggest that PMIs can influence coding of stimulus quality, in some cases by causing an improvement of the contrast between the quality of mixtures and some of their components.

Time course of peripheral heterothermy in a homeotherm

1980 ◽  
Vol 239 (1) ◽  
pp. R126-R129 ◽  
Author(s):  
R. T. Brown ◽  
J. G. Baust
Keyword(s):  
Room Temperature ◽  
Time Course ◽  
Temperature Fluctuations ◽  
Temperature Gradients ◽  
Tissue Temperature ◽  
Central Component ◽  
Sprague Dawley ◽  
Contralateral Limb ◽  
Sprague Dawley Rats ◽  
Peripheral Temperature

The integrity of the peripheral heterothermic response was monitored in adult Sprague-Dawley rats during cold acclimation. Subcutaneous peripheral temperature gradients were simultaneously recorded in the hindlimbs. One limb was exposed to room temperature (22 +/- 2 degrees C) while the contralateral limb was gradually cooled to 0 +/- 1 degrees C. Noncontrols were acclimated at 5 +/- 1 degrees C for periods up to 35 days. Controls responded to the cooling regimen (25 to 0 degrees C at 0.5 degrees C . min-1) in a "poikilothermic" manner indicating local cold-induced vasoconstriction (CIVC). CIVC was not released until tissue temperatures reached 22,3 +/- 2.5 degrees C whereupon nonpatterned limb temperature fluctuations, Lewis' hunting response, were often initiated. The hunting response occurred synchronously in the contralateral warmed limb despite its elevated temperature. The experiments revealed a progressive decrease in the intensity of heterothermy indicative of an earlier onset of cold-induced vasodilation as well as increased resistance to tissue cooling with increasing acclimation time. Following 21 days at 5 degrees C, limb exposure to 0 degrees C resulted in a 2-4 degrees C drop in tissue temperature. The time course of the diminution in peripheral heterothermy is discussed. In addition, evidence supporting the hypothesis of a central component in the regulation of the hunting response is presented.

Sign in / Sign up

Export Citation Format

Share Document