Chemical Senses Practice Flashcards

A set of vocabulary-style flashcards covering sensory transduction and neural coding in the olfactory and gustatory systems based on the provided problem set.

Olfactory receptor cell mutant (dual receptors)

A mutated cell expressing two different receptor proteins, resulting in impaired olfactory capabilities because signals can be sent to the wrong glomerulus and mitral cell, disrupting scent recognition.

Phosphodiesterases (PDEs)

Enzymes that break down cyclic AMP (cAMP); if activated simultaneously with G proteins in olfactory receptors, they prevent transduction because voltage-gated $Ca^{2+}$ channels are never activated.

Voltage-gated $Ca^{2+}$ channels (Olfaction)

Channels whose slower or diminished opening can lead to longer depolarization times, causing olfactory signals to take longer to reach the piriform cortex.

Intracellular $Ca^{2+}$ stores

Stores within taste cells that are necessary for sensing bitter, sweet, and umami tastes; their loss results in an inability to perceive these specific tastes.

Voltage-gated $Ca^{2+}$ channels (Gustation)

Channels in taste cells required for the perception of salty and sour tastes; their absence prevents these tastes from being sensed.

T2R receptor

A specific receptor type that binds bitter tastants.

Labeled line theory

A coding theory suggesting that specific tastes are transmitted through a specified, dedicated pathway; under this theory, lacking T2R receptors would entirely eliminate bitter sensation.

Pattern coding theory

A coding theory where the brain interprets the ratios of activity across different lines; the absence of a specific receptor like T2R would change the overall taste profile and flavor contribution.

Piriform cortex

The area of the brain where olfactory signals are processed after transduction.

Glomerulus

A structure in the olfactory bulb where signals from olfactory receptor cells are sent; correct mapping to these is essential for neural coding of scents.