Limits...
Studies of olfactory system neural plasticity: the contribution of the unilateral naris occlusion technique.

Coppola DM - Neural Plast. (2012)

Bottom Line: Early experiments emphasized naris occlusion's deleterious and age-critical effects.More recent studies have focused on life-long vulnerability, particularly on neurogenesis, and compensatory responses to deprivation.This paper focuses on recent data, new theories, and underappreciated caveats related to the use of this technique in studies of olfactory plasticity.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Randolph Macon College, Ashland, VA 23005, USA. dcoppola@rmc.edu

ABSTRACT
Unilateral naris occlusion has long been the method of choice for effecting stimulus deprivation in studies of olfactory plasticity. A significant body of literature speaks to the myriad consequences of this manipulation on the ipsilateral olfactory pathway. Early experiments emphasized naris occlusion's deleterious and age-critical effects. More recent studies have focused on life-long vulnerability, particularly on neurogenesis, and compensatory responses to deprivation. Despite the abundance of empirical data, a theoretical framework in which to understand the many sequelae of naris occlusion on olfaction has been elusive. This paper focuses on recent data, new theories, and underappreciated caveats related to the use of this technique in studies of olfactory plasticity.

Show MeSH

Related in: MedlinePlus

Simplified model of olfactory signal transduction within OSN cilium. AC⁡III: adenylyl cyclase; AR: adrenergic receptor; BEX: Brain-expressed X-linked protein; ClC: sodium/calcium exchanger; Golf: olfactory g-protein; M3-R: muscarinic acetylcholine receptor; oCGC: olfactory cyclic nucleotide-gated channel; OMP: olfactory marker protein; OR: odorant receptor. The Na+/K+/Cl− cotransporter is not shown. Black arrows: stimulation; red arrows: inhibition (after [7] cf. [8]).
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3368527&req=5

fig2: Simplified model of olfactory signal transduction within OSN cilium. AC⁡III: adenylyl cyclase; AR: adrenergic receptor; BEX: Brain-expressed X-linked protein; ClC: sodium/calcium exchanger; Golf: olfactory g-protein; M3-R: muscarinic acetylcholine receptor; oCGC: olfactory cyclic nucleotide-gated channel; OMP: olfactory marker protein; OR: odorant receptor. The Na+/K+/Cl− cotransporter is not shown. Black arrows: stimulation; red arrows: inhibition (after [7] cf. [8]).

Mentions: The mammalian olfactory system consists of an olfactory mucosa, sequestered in the dorsocaudal part of the nasal cavity, from which olfactory sensory neurons (OSNs) project their axons to the olfactory bulbs, rostral extensions of the telencephalon. At the bulbs, OSNs form synapses with output neurons, the mitral and tufted cells, in neuropil structures known as glomeruli. The largest known mammalian gene family codes for olfactory receptor (OR) proteins, a given OSN expressing but one of ∼1000 genes in the mouse ([9]; Figure 2). All the OSNs expressing a given OR across the nasal cavity converge onto only a couple glomeruli, typically one medial and one lateral in each bulb. Odor information arriving at the bulb from the OSNs is processed by a highly laminar and complex set of direct and indirect pathways present in this well-studied structure [9]. Juxtaglomerular cells which, as their name implies, are part of the glomerular circuit and granule cells residing deeper are the key inhibitory interneurons of the bulb and are particularly important to our story. From the Mitral and Tufted cells olfactory information is transmitted to a group of central targets collectively known as the primary olfactory cortex including accessory olfactory nucleus, the piriform cortex, the entorhinal cortex, and the amygdala. It is in these central areas where a smell is given its appropriate perceptual and emotion qualities [9]. The following discussion will briefly consider the major developmental effects of UNO on each of the three tiers of the olfactory system starting with the bulb since this structure has received the most attention.


Studies of olfactory system neural plasticity: the contribution of the unilateral naris occlusion technique.

Coppola DM - Neural Plast. (2012)

Simplified model of olfactory signal transduction within OSN cilium. AC⁡III: adenylyl cyclase; AR: adrenergic receptor; BEX: Brain-expressed X-linked protein; ClC: sodium/calcium exchanger; Golf: olfactory g-protein; M3-R: muscarinic acetylcholine receptor; oCGC: olfactory cyclic nucleotide-gated channel; OMP: olfactory marker protein; OR: odorant receptor. The Na+/K+/Cl− cotransporter is not shown. Black arrows: stimulation; red arrows: inhibition (after [7] cf. [8]).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3368527&req=5

fig2: Simplified model of olfactory signal transduction within OSN cilium. AC⁡III: adenylyl cyclase; AR: adrenergic receptor; BEX: Brain-expressed X-linked protein; ClC: sodium/calcium exchanger; Golf: olfactory g-protein; M3-R: muscarinic acetylcholine receptor; oCGC: olfactory cyclic nucleotide-gated channel; OMP: olfactory marker protein; OR: odorant receptor. The Na+/K+/Cl− cotransporter is not shown. Black arrows: stimulation; red arrows: inhibition (after [7] cf. [8]).
Mentions: The mammalian olfactory system consists of an olfactory mucosa, sequestered in the dorsocaudal part of the nasal cavity, from which olfactory sensory neurons (OSNs) project their axons to the olfactory bulbs, rostral extensions of the telencephalon. At the bulbs, OSNs form synapses with output neurons, the mitral and tufted cells, in neuropil structures known as glomeruli. The largest known mammalian gene family codes for olfactory receptor (OR) proteins, a given OSN expressing but one of ∼1000 genes in the mouse ([9]; Figure 2). All the OSNs expressing a given OR across the nasal cavity converge onto only a couple glomeruli, typically one medial and one lateral in each bulb. Odor information arriving at the bulb from the OSNs is processed by a highly laminar and complex set of direct and indirect pathways present in this well-studied structure [9]. Juxtaglomerular cells which, as their name implies, are part of the glomerular circuit and granule cells residing deeper are the key inhibitory interneurons of the bulb and are particularly important to our story. From the Mitral and Tufted cells olfactory information is transmitted to a group of central targets collectively known as the primary olfactory cortex including accessory olfactory nucleus, the piriform cortex, the entorhinal cortex, and the amygdala. It is in these central areas where a smell is given its appropriate perceptual and emotion qualities [9]. The following discussion will briefly consider the major developmental effects of UNO on each of the three tiers of the olfactory system starting with the bulb since this structure has received the most attention.

Bottom Line: Early experiments emphasized naris occlusion's deleterious and age-critical effects.More recent studies have focused on life-long vulnerability, particularly on neurogenesis, and compensatory responses to deprivation.This paper focuses on recent data, new theories, and underappreciated caveats related to the use of this technique in studies of olfactory plasticity.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Randolph Macon College, Ashland, VA 23005, USA. dcoppola@rmc.edu

ABSTRACT
Unilateral naris occlusion has long been the method of choice for effecting stimulus deprivation in studies of olfactory plasticity. A significant body of literature speaks to the myriad consequences of this manipulation on the ipsilateral olfactory pathway. Early experiments emphasized naris occlusion's deleterious and age-critical effects. More recent studies have focused on life-long vulnerability, particularly on neurogenesis, and compensatory responses to deprivation. Despite the abundance of empirical data, a theoretical framework in which to understand the many sequelae of naris occlusion on olfaction has been elusive. This paper focuses on recent data, new theories, and underappreciated caveats related to the use of this technique in studies of olfactory plasticity.

Show MeSH
Related in: MedlinePlus