| Background and ObjectiveOlfactory perception originated in the olfactory epithelium in the identification of a large number of odorant receptors. After the odorant enter into the olfactory bulb, the olfactory information will be transmited to anterior olfactory nucleus, olfactory tubercle, cingulate gyrus, entorhinal cortex and piriform cortex. The piriform cortex is a primitive paleocortex that is critical for the synthetic perception of odors, which is one of the first cortical destinations of olfactory information in mammals. The piriform cortex is the largest cortical area that receives direct synaptic input from olfactory bulb, which in turn receives direct input from the olfactory epithelium at the back of the nose. Despite piriform cortex superficial simplicity, the piriform cortex is a extremely subtle and intricate neural circuit.Exciting new findings have indicated that a large of neurons and circuits in the piriform cortex process odor information. Olfactory bulb damage results neuronal degeneration and inhibition Interneurons important cellular changes in second layer of piriform cortex. Through the olfactory bulb damage, cut off the olfactory bulb neurons and on Piriform Cortex second layer pyramidal neuron has a significant impact, piriform cortex receives input from the olfactory bulb, but not projected. Therefore, how olfactory information is transmited after olfactory bulb damage? Through the olfactory bulb damage induced nerve amputation whether could stimulate Piriform Cortex nerve regenerated and its potential?In this study, take the olfactory bulb damage rats as our research object, exploredwhether rose volatile oil have some influence on piriform cortex regeneration, and the change of neurotransmitters, for instance, Glu and GABA. At the same time, with a view to provide scientific basis and new inspiration on Rose volatile oil sniffing impact on the relationship among piriform cortex regeneration and olfactory bulb damage and neurological disorders.Part 1 Piriform Cortex CytoarchitectureMethodsTake the brain of the normal rats brain,fixed continuous 48h. The fixed brain tissue after dehydration, transparent, wax dipped, embedded. Slice prepared tohematoxylin-eosinstaining, and then observethe morphology of Piriform Cortex.ResultsHE staining showed that neurons in Piriform Cortex were completed, and showing the three-layer distribution, a larger number of neurons distributed in the second layer. Piriform Cortex area neurons were round or oval, and have clear structure.Part 2 Olfactory bulb damage prepare piriform cortex neurons degeneration modelMethodsAccording to rat brain map, using stereotaxic instrument to find the location of the olfactory bulb, olfactory bulb damage after drilling carried out. While the successful model rats were randomly divided into five groups:24h after bulb damage,72h after after bulb damage,7d after bulb damage,14d after bulb damage, rose volatile oil sniff group.ResultsAfter the destruction of the olfactory bulb of rats compared with the control group, loss of appetite, reduced activity, whichever behind observed rat olfactory partially missing or damaged. And rose volatile oil sniff group were implemented rose volatile oil sniff.One day after the destruction of the olfactory bulb, sniff rats were prepared to rosebuds extract sniff. Sniffing each time for 1 h,2 times/d, continuous 14 d.Part 3 Neurons changes in piriform cortex before and after olfactory bulb damage ratMethodsTake the brain of each group, fixed continuous 48h. The fixed brain tissue after dehydration, transparent, wax dipped, embedded. Slice prepared to Nissl staining, Immunohistochemistry and statistical analysis.Results1. Piriform Cortex neurons in the control group were normal, clear nucleolus nucleus membrane; the olfactory bulb damage after 24h,72h Piriform Cortex degeneration occurs, Nissl staining gradually weakened; olfactory bulb damage after 7d Piriform Cortex neurons begin to rebuild, Nissl staining gradually returned to normal, in the 14d Piriform Cortex Nissl body recover nearly normal level; rose volatile oil sniff group at 14d Piriform Cortex neurons in Nissl body higher than that sniff group.2. Glu immunoreactive positive cells are widely distributed in the Piriform Cortex, the positive cell body into a round, oval, brown granular. Olfactory bulb damage after 24h,72h after the Piriform Cortex neurons positive cells increased cell coloring strengthen; 7d,14d Piriform Cortex neurons after reduction in the number of positive cells in the olfactory bulb slightly damaged, rose volatile oil sniff group and the control group no significant difference compared3. After the destruction of the olfactory bulb Piriform Cortex GABA-positive neurons and reduced compared to the control group, rose volatile oil sniffing rats Piriform cortex GABA-positive neurons cells decreased significantly4. Compared with 14 d group and 72h group, rose volatile oil sniff group Glu gray value was increased, the difference was statistically significant (p<0.05). And 14d group and 72h group, rose volatile oil sniff group GABA gray value wasreduced, the difference was statistically significant (p<0.05).Conclusion1.Olfactory bulb damage could cause Piriform cortexdeterioration.2.The degeneratedneurons cells could regenerate.3.Rose volatile oilhas a certain impact onPiriform cortex regeneration after degeneration. |
PDF Full Text Request