Question

the olfactory code for a single odorant is based on combinatorial input from multiple olfactory neurons:

a) different sets of responding odorant receptors code for different chemicals but also for different concentration of the same chemical. how does lateral inhibition contribute to these differences?

b) why do you think there is no apparent "logic" in the smell of similar vs dissimilar chemicals?

c) would one chemical be coded by the same receptor combination in various animals? yes or no. explain your answer.

d) how is it possible that two AAs changes in one receptor change response to androstenone so drastically?

Answer 1

• Olfactory stimuli are typically vaporous chemicals that bind to odorant receptors on olfactory sensory neurons in the nasal epithelium. Pure chemicals differ from one another incrementally rather than continuously, even small differences in odorant structure can change multiple chemical dimensions that might be relevant to receptor interaction.
• Increasing concentration of the same odorant recruit responses in glomeruli located nearby the originally activated ones, with the overall effect of increasing the area of the response roughly in proportion to odorant concentration. Such as valeric acid and methyl valerate are the one that tend to activate large cluster of glomeruli at high concentration whereas odorant molecule with less flexibility activate fewer glomeruli.
• Glomeruli responding to odorant with similar functional groups, hydrocarbon structures or overall molecular properties are often clustered together in the bulb.However there are some chemical features that are not represented by there own glomerular modules.