Disease relevance of Olfactory Pathways

• Bovine herpesvirus 5 glycoprotein E is important for neuroinvasiveness and neurovirulence in the olfactory pathway of the rabbit [1].
• Clinical and pathological studies have revealed that in multiple sclerosis (MS) the involvement of the optic tracts is much more frequent than that of the olfactory tracts [2].
• The other two patients exhibited normal olfactory pathway morphology, and for them the possibility of acquired sensorineural anosmia could not be ruled out [3].

Psychiatry related information on Olfactory Pathways

• Biochemical assay data revealed that dopamine levels were significantly reduced both in nucleus accumbens septi (NAS) and olfactory tubercle (OT) but not neostriatum; thus it was concluded that amphetamine- and apomorphine-induced locomotor activity is mediated by the mesolimbic dopamine system [4].
• Computational parallels between the biological olfactory pathway and its analogue 'the electronic nose': Part I. Biological olfaction [5].

High impact information on Olfactory Pathways

• This information is then transmitted to piriform (olfactory) cortex, via axons of olfactory bulb mitral and tufted (M/T) cells, where it is presumed to form the odor percept [6].
• Sniffing Out NMDA Receptors in the Olfactory Cortex [7].
• Our results suggest that Pax6-regulated ephrin A5 acts as a repulsive molecule for olfactory cortex neurons in the developing telencephalon [8].
• Here, we report Pax6-dependent alignment of the olfactory cortex neurons in the developing telencephalon [8].
• Pax6-dependent boundary defines alignment of migrating olfactory cortex neurons via the repulsive activity of ephrin A5 [8].

Chemical compound and disease context of Olfactory Pathways

• Effects of 6-hydroxydopamine lesions of the nucleus accumbens septi and olfactory tubercle on feeding, locomotor activity, and amphetamine anorexia in the rat [9].

Biological context of Olfactory Pathways

• 2 Pentobarbitone (0.1-0.3mM) depressed the evoked synaptic potentials without any significant depression of impulse conduction in the afferent fibres of the lateral olfactory tract (1.o.t) [10].
• Synaptic transmission in the isolated olfactory cortex slice from the rat was monitored by recording the surface field potentials evoked on lateral olfactory tract (LOT) stimulation [11].
• Long-term potentiation (LTP) was demonstrated in a slice preparation of piriform (olfactory) cortex [12].
• Intracellular recordings from guinea-pig olfactory cortex neurones revealed a dual effect of zinc: firstly (at 100-500 microM), the responses to bath-applied GABA, muscimol and 3-aminopropanesulphonate were reversibly enhanced, and secondly (at 25-500 microM), the excitatory postsynaptic potential was dramatically prolonged [13].
• High densities of [3H]CFT binding sites were present in dopamine-rich brain regions, including the caudate nucleus, putamen, nucleus accumbens, and olfactory tubercle [14].

Anatomical context of Olfactory Pathways

• Autoradiograms of [3H]MeTRH binding showed highest concentrations of TRH receptors in the rhinencephalon, including accessory olfactory bulb, nuclei of the amygdala, and the ventral dentate gyrus and subiculum of the hippocampus [15].
• Northern blot analysis revealed the presence of an SSTR4 mRNA species of approximately 4 kilobases in select regions of the monkey brain, including the hippocampus, hypothalamus, cortex, and striatum, with little or no receptor mRNA detected in either the olfactory tubercle, medulla, cerebellum, or amygdala [16].
• Assuming the CNP activity and the BP content are true measures of the total myelin content of a given tissue, it appears that olfactory tracts have smaller amounts of myelin [2].
• Scar tissue, formed after penetrating injuries to the lateral olfactory tract (LOT), cortex, perforant pathway, and spinal cord, contained numerous spindle-shaped cells expressing high levels of sema III mRNA [17].
• The effects of the thiol group reagent 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) on D2 dopamine receptors have been examined in three brain regions (caudate nucleus, putamen and olfactory tubercle), and in the anterior and neurointermediate lobes of the pituitary gland [18].

Associations of Olfactory Pathways with chemical compounds

• A substantial improvement in the rate of detection of organic lesions affecting the olfactory pathway can be achieved by substituting odours such as musk ketone, exaltolide, linalyl acetate and coumarin for those in current use [19].
• Cellular uptake of gamma-aminobutyric acid influences its potency on neurones of olfactory cortex in vitro [proceedings] [20].
• Guinea pigs were unilaterally bulbectomised and the contents of aspartate, glutamate and GABA measured in slices of olfactory cortex taken from the lesioned and intact hemispheres [21].
• Levels and synthesis of glutamate and aspartate in the olfactory cortex following bulbectomy [21].
• Release of radioactive glutamic acid from thin sections of guinea-pig olfactory cortex in vitro [22].

Gene context of Olfactory Pathways

• As the olfactory deficits vary according to chemical identity and concentration, they indicate that a spectrum of arrestin activity is essential for odor processing depending upon the particular olfactory pathway involved [23].
• These results suggest that olfC is allelic to mys and functions together with alphaPS2 integrins in the olfactory pathway in Drosophila [24].
• Here, we show that in the absence of the LIM-homeodomain (LIM-HD) gene Lhx2, a particular amygdaloid nucleus, the nucleus of the lateral olfactory tract (nLOT), is selectively disrupted [25].
• Neurons dually-labeled for TH and AADC were found in the anterior olfactory nucleus, olfactory tubercle and the ventral margin of the rostral nucleus accumbens [26].
• CONCLUSION: The dentate hilar neurons projecting to the olfactory tubercle cannot be considered displaced cells of CA3 but represent true dentato-tubercular projection neurons [27].

Analytical, diagnostic and therapeutic context of Olfactory Pathways

• Histological examinations of carbocyanine dye 1,1'diocadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI)-labeled olfactory bulbs and electrical stimulation of the olfactory tracts in a subset of experiments suggested that the majority of the recorded olfactory bulb neurons in this study were mitral cells [28].
• Immunofluorescence was used to double label for IP3R and for gamma-aminobutyric acid (GABA) or for projection neurons, which were retrogradely labeled following dextran injection into the lateral olfactory tract (LOT) [29].
• The persistent excitatory effects of the muscarinic agonist oxotremorine-M were investigated in guinea-pig olfactory cortex neurons in vitro (28-30 degrees C) using a single-microelectrode current-clamp/voltage-clamp technique [30].
• In this study immunohistochemistry is used to investigate the distribution of opioid peptides, substance P (SP), neuropeptide Y (NPY) and acetylcholine (ChAT) in the olfactory tubercle (OT) of the cat [31].
• To measure the effect of muscimol, the input conductance was measured either directly using intracellular microelectrodes or by measuring its effect on the amplitude of the evoked compound potentials recorded from the slice surface after stimulating the lateral olfactory tract [32].

References