5 - Chemical Senses Flashcards
What is olfaction?
The sense of smell, a multidimensional coding sequence.
What is labelled line code?
When one neurone detects one taste.
What is combinatorial code?
When multiple neurones detect one taste.
What does second messengers do in the olfactory system?
They amplify sensory signals.
What type of receptors are human olfactory receptors?
GPCRs (Ion channels in insects)
What do olfactory receptors do as they mature?
They narrow down to express one type of neurone.
How do olfactory receptors expressing the same neurone converge?
Onto the same glomerulus like a ball of thread.
What do sensory neurones do?
Transfer information to second order neurones at glomeruli.
What are some examples of projection neurones?
Mitral and tuffed cells
What do projection neurones do?
Receive info from the glomerulus which allows for specificity.
What is the function of the first relay synapse?
To transform the odour code
What effect does synaptic adaptation have in the first relay synapse?
It emphasises the start of the odour.
What does converging sensory neurons on to second order neurones do?
It reduces noise and strengthens weak responses.
What are the functions of lateral cross-talk?
1- To gain control - in the presence of strong odours lateral cross-talk can activate inhibitor neurons.
2 - De-correlation - they make the responses to the different odours as different as possible.
What olfactory behaviour does the Piriform cortex in the brain regulate?
Learned association of smells.
