GS olfactory Flashcards
list advantages of olfaction
locate and track prey
long distance warning beyond line of sight in the dark
sexual attraction
hedonic reward system
VISCERAL RESPONSE
what does smelling food cause
salivation and gastric motility
what causes salivation and gastric motility
smelling food
what does a noxious smell cause
gag
what smell causes you to gag
noxious
infants recognise mothers by what
scent
mothers can recognise the _____ of her baby
scent
women housed together synchronise what
menstrual cycles
the neuroepithelium contains what kind of neurons and what two types of cells
olfactory sensory neurons (OSN)
sustentacular cells
stem cells (basal cells)
OSN’s are generated from what cells
basal cells
where do ORN axons make new connections to
the olfactory bulb
(sits above cribriform plate
wiring of the olfactory system involves what kind of cells
mitral cells
and two populations of interneurons
wiring of the olfactory system involves mitral cells and what two populations of interneurons
periglomerular cells and granule cells
apical dendrites of sensory neurons project through what cavity and what type of cells
support cells and nasal cavity
apical dendrites are capped by what
and what do they project through (cavity)
capped by dendritic cilia projecting into specialised mucus in the nasal cavity
the cilia have receptor sites for what molecules
odorant molecules
odorant molecules are structures for what
olfactory signal transduction
life span of olfactory sensory neurons
short lived (1-2) months
what do olfactory sensory neurons regenerate from
basal stem cells
what is the function of the cribriform plate
separates the nose from the brain
what structure separates the nose from the brain
cribifrom plate
OSN pass through what structure with holes to enter the brain
cribiform plate
what neurons pass through the cribiform plate through tiny holes to enter the brain
OSN
what kind of receptors are odorant receptors
GPCR’s
mammalian odour receptors are related to what other receptors
chemosensory receptors
what receptors are odorant receptors
T1R, TR2
what receptors are taste receptors
VR3
what kind of receptors are vomeronsal receptors
DOR, DGR
odors are detected by receptors and transduced into an electrical signal. This results into the generation of what
generation of an action potential
the action potentials travel down axons of what
this action potential eventually meets with other axons and ends up forming what nerve
olfactory receptors
olfactory nerve (CN1)
OR’s are GPCR’s which activate what via which G protein
- adenyl cyclase type III
- via G protein -> G(olf)
Camp opens what
cyclic-nucleotide gated cation channel
(Ca and Na influx)
once cAMP opens a non selective, cyclic nucleotide gated cation channel what does it do to the ciliary membrane
depolarises the ciliary membrane
a Ca2+ influx through the CNG channels opens what
Ca2+ activated chloride channels
Cl- leaves the ORN ____________ its concentration gradient
against
once Cl_ leaves the ORN against its concentration gradient, what does this do
further depolarises the cell and provides amplification
action potential generation in Olfactory receptor neurons within the olfactory signal transduction releases what
glutamate
Neuronal Cl_ channels normally mediate what kind of receptors
inhibitory
OSN’s maintain an unusually (high/low) intracellular Cl- concentration due to what kind of membrane pump
- high
- NKCC1
OSN maintains what its own Cl- battery in case of what
if the Na+ gradient in the mucus is insufficient to support a threshold current
OSN maintains what its own Cl- battery in case the Na+ gradient in the mucus is insufficient to support a threshold current and uses it to do what
boost the response
odour molecules activate many what proteins
G proteins
one AC activates many what
cAMP molecules
adaptation via Ca and other proteins allows for what
sensitivity and extends the range of concentration of odour stimulation
each sensory neuron responds to a what
or what
single odorant
or a specific repertoire chemically related odorant
an odour is __________ by a specific combination of responding neurons
encoded
sensory neurons respond to odorant by what
which does what to the neuron
- inward current
- depolarises the neuron
there is a relationship between odorant concentration and size/duration of the inward current, sufficient depolarisation triggers what
an action potential
what is the structure of a glomerulus
spherical structures containing incoming axons of the OSN
what is the first processing station in the brain
glomerulus
what kind of action does a periglomerular cell have
inhibitory
what does a periglomerular cell do
connects one glomerulus to another
what kind of action does a granule cell have
inhibitory
what does a granule cell do
connect sone mitral cell to another
where is the granule cell
in granule cell layer
mitral cells receive odour information from where
receptor/sensory neurons
what do mitral cells do with odour information
refine the signal and amplify it
where do mitral cells receive input from when they refine the signal and amplify it
what do they then do with the message
via inputs from PG and GR
then they relay the message
when mitral cells are activated impulses flow from the olfactory bulbs through the lateral olfactory bulbs to where
thalamus
hypothalamus
amygdala
when mitral cell are activated impulses flow from the olfactory bulbs and then eventually to theto the thalamus
where does the impulse go after this
pirform lobe of the olfactory cortex and part of the frontal lobe
where are smells consciously interpreted and identified
frontal lobe
smells that are associated with danger trigger what response
sympathetic fight or flight
why is olfaction strongly tied to memory
because it skips the thalamus and the main olfactory bulb is directly connected to the amygdala
what is involved in the formation of memories and emotionalexperiences
amygdala
how many receptors are expressed by a single sensory neuron
1
cells expressing the same receptor converge on how many glomeruli
1 or few
each mitral cells innervates a single glomerulus via what
apical dendrites
cells for detecting an odour are dispersed where
in the epithelium of the glomerulus
expression of single OR genes requires the presense of what
a functional OR
paternal and maternal alleles of the same OR occupy what
different areas in the glomerulus
targeted KO’s pf golf and CNGA2 cause what
severe anosmia
OR-derived glomerular cAMP signals are not required for what
OSN projection
OR govern both the coarse and refined map via what
cAMP levels and electrical activity/ca influx respectively
expression of kir2.1 (a K channel) in compound genetic mice lacking dox inhibits what
neural activity in the OE
what ion channel is kir2,1
potassium
expression of kir during development (in utero and post natal) shows what
mistargeting/lack of glomerulus targeting
what is specific anosmia
the inability to smell one specific compound, amid otherwise normal smell perception
each mitral cell innervates a single what
glomerulus
different chemical domains are recognised by what
OR
multiple ORs have the ability to recognise the ____ domains
same
a particluar OR expressing neuron projects to what
a specific glomerulus
