Chemical senses Flashcards
What are the two types of encoded information in the CNS?
labelled line code
combinatorial code
What is the role of 2nd order neurons in olfactory transduction?
amplification of signals
What kind of receptors are olfactory ones in mammals and in insects?
mammals- GPCRs
insects- ion channels
What is a glomerulus?
where olfactory neurons that express a singular receptor converge and transfer info to 2nd order neurons
Why is the convergence of olfactory neurons necessary?
reduces noise and strengthens weak responses
Why is there lateral cross talk between glomeruli?
so that they can be sensitive to both very weak and very strong odours
mechanism of gain control- still sensitive to changes even when there is a strong odour
Where are further olfactory pathways in humans located?
piriform cortex and amygdala
Where are further olfactory pathways in insects located?
mushroom body and lateral horn
What part of the brain is responsible for innate odour responses?
amygdala/ lateral horn
Stereotyped behaviours vs learned behaviours
innate odour neurons are specific to give stereotyped behaviours
learned behaviours are arbitrary and random
How does taste transduction work?
many of the same principles as olfactory, uses ionotropic and metabotropic receptors and amplification of signals
Where in the brain do taste signals get sent to?
solitary nucleus
What sharpens taste?
lateral inhibition
What is lateral inhibition?
when stimulated neurons reduce the activity of neighbouring neurons
