Chemical Senses Flashcards
cAMP function
opens cation channel
Second messenger function olfactory system
amplify sensory signals
Insect olfactory receptors
Ion channels
Olfactory receptor specialisation
some receptors are very specialised, some very general
Olfactory sensory neuron maturation
mature neurons express a single olfactory receptor
How do we know mature olfactory sensory neurons only express a single neuron
single cell whole transcriptome sequencing
Olfactory convergence onto glomerulus
Olfactory sensory neurons expressing the same receptor converge on the same glomerulus
In drosophila what is the olfactory bulb the same as
antennal lobe
Olfactory bulb
structure in forebrain of vertebrates that receives neural input about odours
Sensory neurons transfer information to ?
second order neurons at glomeruli
What is the equivalent to olfactory sensory neurons in drosophila
olfactory receptor neurons
True or False - one to one between sensory neurons and second class of neurons
true
What does receptor specific matching of sensory neurons to second order neurons ensure
odour specificity is carried through
What are mitral cells and tufted cells equivalent to in drosophila
projection neurons
What do mitral and tufted cells project to
the brain
What is the first relay synapse important for - olfactory
transformation of the odour code
What is the first relay synapse between - olfactory
sensory neurons and second order neurons
What synaptic adaptation emphasise
start of the odour
Describe the first relay synapse - olfactory
rapidly adapting, weakens over time
What does the first relay synapse (olfactory) allow
nervous system to focus on changes in odour
What is the function of converging sensory neurons onto second order neurons
reduce noise, strengthens weak responses
what is the function of lateral cross talk
gain control and de-correlation
Lateral cross talk - gain control function
sensitive to very weak and very strong odours
Lateral cross talk - de-correlation
make responses of neuronal population to different odours as diff as possible
Olfactory behaviours
learned and innate
Learned olfactory behaviour brain area human
piriform cortex
Learned olfactory behaviour brain area insects
mushroom body - kenyon cells
Innate olfactory behaviour humans brain area
amygdala
Innate olfactory behaviour brain area insects
lateral horn
What is required for innate odour responses humans
cortical amygdala
How can you show a brain region is responsible for a certain behaviour
silence that brain region
What are the purposes of innate and learning circuitry
innate - categorise, learned - discriminate
What is the difference between innate and learning circuitry activity
innate - dense, learning - sparse
How do bacteria move
swim straight (runs) or turns (tumbles)
What is the effect of increasing nutrient concentration on bacterial movement
run more, tumble less
What organism uses the same rule as bacteria
C.Elegans
How can transience be generated in olfactory stimuli
moving head
What receptors does taste transduction use
metabotropic and ionotropic
What is the function of signal transduction pathways
amplify signals
What does bitter inhibit
sweet
How does bitter inhibit sweet
lateral inhibition
