Smell + Auditory Flashcards
What is the transcription pathway for the olfactory system?
Binding to membrane receptor -> G protein stim -> Adenyl Cyclase -> cAMP cleavage -> Ca 2+ and Na+ channels open -> Cl- channels open -> membrane depolarization
What desensitizes the phosphorylation receptor?
Phosphorylation
The olfactory receptor cells are expressing how many genes/proteins?
one
How do receptors help us discern so many smells?
Roughly 2000 glomeruli in the olfactory bulb are innervated by many axons
What genetic information can be said about the innervation of target glomeruli?
They are innervated by all receptor cells expressing the same gene
How many genetically different receptor cells exist in the olfactory system?
approx 1000
What are the three types of information processing cells in the olfactory bulb?
Mitral Cells
Periglomerular Cells
Granule Cells
What is the role of a mitral cell?
Receive the input from the OB and send it to the olfactory cortex
What is the role of the granule cells?
They inhibit the mitral cells and refine odor representation
What is the role of a periglomerular cell?
It inhibits and modulates the synaptic strength between the olfactory nerve and mitral cell
What are the two projections of the olfactory bulb?
- Olfactory cortex
- Olfactory tubercule -> Medial dorsal nucleus (thalamus) -> Orbitofrontal cortex
What animal system is attenuated to pheromones?
Accessory olfactory system
What is another word for nose in an accessory olfactory system?
The vomeronasal organ
What part of the accessory olfactory system gets innervated by the nose?
The AOB (Accessory olfactory bulb)
What is the hypothalamus equivalent in the accessory olfactory system?
The Vomeronasal corticostratum (VCS)
What is the hearing range of humans? (intensity)
0-100 dB
What is the frequency range of human hearing?
20Hz to 20kHz
What ossicle bone is adjacent to the cochlea?
The stapes
What is the cochlea filled with?
Fluid
Where do high frequency sounds vibrate the basilar membrane?
The base
What is the covering of the hair cells in the ear called?
The stereocilia
Which way does the basilar membrane / stereocilia oscillate?
Basilar membrane up/down, and stereocilia left/right
What type of gates are auditory channels?
Mechanically gated
What is the point of the ribbon structure of auditory receptor cells?
They have a graded release of NTs based on Ca+ concentrations based on movement
What is special about inner hair cells?
K+ influx causes depolarization, and NT release is not spiking, many spiral ganglion cells per hair cell
What is the characteristic frequency of a sound?
It is a frequency that can be heard at a significantly lower dB threshold
What do cochlear implants connect to?
The cochlea
What is the word to describe the organization of the auditory cortex to resemble the organization of the basilar membrane?
Tonotopic coding
How does the brain calculate localization of a sound source?
The interaural time delay
