up: [[HD 2230 Introduction to Behavioral Neuroscience]] Tags:: # Smell sensation and perception Smell is one of the most ancient of sensations. This is why [[What sensory pathway does the brain prioritize|the brain might prioritize information from these senses.]] For example, memories created from averse taste experiences have been known to stay for years and years. ###### What are pheromones? Special chemicals that are capable of acting like external hormones to other animals. ###### What does the vomeronasal organ (VNO) do? It detects pheromones in the air. ###### Do humans have a vomeronasal organ (VNO)? They don't. ###### How do you know if an animal have a VNO? If they have wet noses. ## Reception ![[Pasted image 20221012105629.png]] #### What do olfactory receptor cells do? Humans have hundreds of different olfactory receptor neurons with cilia ends that are responsive to many different odorant molecules. These receptors send axons to glomeruli in the olfactory bulb. ![[Pasted image 20221012104956.png]] ###### What determines the scent you perceive? The specific combination of glomerulus that are stimulated determine the scent you perceive. ## Transduction ##### How do scents get transduced in olfactory receptor cells? Odorant molecules attach to [[Neuropharmacology#What are the two types of receptors|metabotropic]] receptors on olfactory receptor cells causing second order messengers to release activating cAMP that open ion gated Na+ and Ca2+ channels depolarizing cells. ## Transmission #### What is the path of sensory information flow in the olfactory system in the brain? Unlike other sensory systems, action potentials from the olfactory bulb get transmitted to the hypothalamus, amygdala, and primary olfactory cortex before the thalamus. This means you can react to smell sensations faster than any other sensory system. ![[Pasted image 20221014101444.png]] ## Analysis #### What determines the odor we perceive? The pattern of glomeruli that are activated by unique combinations of receptor cells leading to different combinations of neurons sending action potentials analyzed in the primary olfactory cortex. ![[Pasted image 20221019084802.png]] ## Integration ###### What is retronasal smelling? Retronasal olfaction is the perception of odors emanating from the oral cavity during eating and drinking, as opposed to orthonasal olfaction, which occurs during sniffing. This is why when you close your nose or have a cold while eating food doesn't taste nearly as good. Related: ___ # Resources