The ability of acetylcholine (ACh) to alter specific functional properties of the cortex endows the cholinergic system with an important modulatory role in memory formation. For example, an increase in ACh release occurs during novel stimulus processing, indicating that ACh activity is critical during early stages of memory processing. During novel taste presentation, there is an increase in AC...

Crushing or transecting the chorda tympani nerve of the gerbil (Meriones unguiculatus) caused ipsilateral degeneration of taste buds in the fungiform papillae. In less than two weeks some taste fibers regenerated into the tongue and formed new taste buds and receptor cells. The recovery process was evaluated electrophysiologically in 53 gerbils by acute recording proximal to the nerve injury si...

Bitter taste is one of the five basic taste sensations which is mediated by 25 bitter taste receptors (T2Rs) in humans. The mechanism of bitter taste signal transduction is not yet elucidated. The cellular processes underlying T2R desensitization including receptor internalization, trafficking and degradation are yet to be studied. Here, using a combination of molecular and pharmacological tech...

We previously showed that rat taste buds express several adenylyl cyclases (ACs) of which only AC8 is known to be stimulated by Ca2+. Here we demonstrate by direct measurements of cAMP levels that AC activity in taste buds is stimulated by treatments that elevate intracellular Ca2+. Specifically, 5 microM thapsigargin or 3 microM A-23187 (calcium ionophore), both of which increase intracellular...

A strong positive association exists between the ingestion of alcohol and sweet-tasting solutions. The neural mechanisms underlying this relationship are unknown, although recent data suggest that gustatory substrates are involved. Here, we examined the role of sweet taste receptors and central neural circuits for sugar taste in the gustatory processing of ethanol. Taste responses to ethanol (3...

BACKGROUND Flavor perception, the integration of taste and odor, is a critical factor in eating behavior. It remains unclear how such sensory signals influence the human brain systems that execute the eating behavior. METHODS WE TESTED CEREBRAL BLOOD FLOW (CBF) IN THE FRONTAL LOBES BILATERALLY WHILE SUBJECTS CHEWED THREE TYPES OF GUM WITH DIFFERENT COMBINATIONS OF TASTE AND ODOR: no taste/no ...

Recent studies have suggested that the response profiles of taste-responsive cells in the brainstem may be modulated by inhibitory interactions, potentially originating from activity in peripheral taste nerves. This idea was explored by testing the hypothesis that brief (100 msec) pulses of taste stimuli would alter the responses to subsequently presented tastants in the nucleus of the solitary...

We previously showed that rat taste buds express several adenylyl cyclases (ACs) of which, only AC8 is known to be stimulated by Ca 2+. Here, we demonstrate by direct measurements of cAMP levels, that AC activity in taste buds is stimulated by treatments that elevate intracellular Ca 2+. Specifically, 5 :M thapsigargin or 3 :M A23187 (calcium ionophore), both of which increase [Ca 2+ ] i , lead...

N-(1-Carboxyethyl)-6-hydroxymethyl-pyridinium-3-ol inner salt (alapyridaine), recently identified in heated sugar/amino acid mixtures as well as in beef bouillon, has been shown to exhibit general taste-enhancing activities, although tasteless on its own. Differing from other taste enhancers reported so far, racemic (R/S)-alapyridaine and, to an even greater extent (+)-(S)-alapyridaine, the phy...

The localization of Mg++ activated adenosine triphosphatase (ATPase) activity in rat fungiform taste buds was demonstrated by electron microscopic histochemistry. Reaction product was found on the cell membrane of the taste cells, but not within their cytoplasm. Especially strong reaction occurred in the taste pore. Besides, enzymes were observed in axon-Schwann cell and axon-type I cell inters...