click below
click below
Normal Size Small Size show me how
Olfactory Bulb
Question | Answer |
---|---|
turbenent bones | mix up air in nasal cavity so that the different soptiveness rates and binding constants of different odors will be the biggest factor in their transduction rates (as opposed to airflow stuff) |
glomerulus | spherical struct at periph of OB where the synapses form between the olfactory nerve terminals and dendrites of mitral, periglomerular and tufted cells. |
gamma osc | 40-100hz in rodents. small waves on theta waves. associated w/ discrim of similar odors. caused by negative feedback loop at dendrodendritic synapse btwn mitral and granule cells. amplitude correlated w/how synced up the feedback loop is. |
theta osc | 4-12hz. big waves which sync up with rat respiration. hard to study for fxn... but strong amplitude on "reversal" |
mitral cells | excitatory neurons in the OB; they receive info from axons of ORN from the epithelium. they send their axons, in turn, to the piriform cort and others. fire in bursts at sniff rate when sniff rate is low. when its high, they fire tonically. cf. gamma osc |
beta osc | 15-30hz in waking rodents. coherent w/other brain systems? enables information transfer/learning? ESP for GNG |
granule cells | small, GABAergic, axonless interneurons. inhibit. cf. Gamma osc. |
primary olfactory cortext | 1)anterior olfactor nucleus, 2)rostral olfactory cortex, 3)lateral olfactory cortex. the piriform cortex is found in the latter |
ORN | odor receptor neurons. one receptor type/one feature. one receptor type/ many molecules. one molecule/ many receptor types. project into OB contralaterally to gloms. |
pathway for ORN | 1)odor bind to membrane odorant recept proteins 2)g-protein stim 3)activation of adenylyl cyclase 4)binding of cyclic AMP to specific cation channels 6)opening of cation chann, influx of Na+ & Ca2+ 7)Opening Ca2+activated Cl (out) channels, depol |
layers of OB | 1) glomerular layer (synapses between ORN and mitral) 2) ext plexiform layer (synapses btwn mitral and granule), 3)M/T layer (soma of mitral), 4) internal plex, 5)granule layer (soma of granule) |