Neuron Synthesis

In previous studies, Frank and Byram’s article suggest that taste and smell interactions are dependent on taste and odor. In their experiments, they gave subjects strawberry

These receptors record on a extensive form of sensory modalities including changes in temperature, stress, touch, sound, mild, style, odor, physique and limb actions, and even blood pressure and chemistry. Scientists have recognized for nearly a hundred thirty years that distinct afferent nerve fibers of the peripheral nervous procedure are in contact with specialized non neural receptive buildings which realize and transmit sensory knowledge from the periphery to the Central Nervous System. The non neural receptive structure in conjunction with its afferent nerve fiber is mainly called a

Name and describe the parts of the brain involved in the chemical sense of taste.

Activators of Adenylate Cyclase would cause production of cAMP, which is a second messenger. This would amplify the signal and increase the extent of the scent.

Tastes and smells are the perception of chemicals in the air. The close relationship with smell and taste helps people perceive the flavors of food. Anyone with a cold has experienced that moment where they can not perceive the flavors of food because their smell has been “impaired” due to a stuffy nose. Taste itself is focused chemicals that have sweet, salty, sour, bitter, or savory taste. “The sense of taste influences food

I decided to research Anosmia to do my chapter 3 activity over. Anosmia is a condition that affects olfaction and the olfactory system. The olfactory system is our sense of smell, and consists of the olfactory epithelium; olfactory receptor cells; olfactory bulbs; Amygdala; The olfactory cortex, the limbic system; the thalamus; and the orbitofrontal cortex. Odors travel through the nasal passages and reach the olfactory epithelium. The olfactory epithelium has around 10 million olfactory receptor cells that detect the odor that travels up the nasal cavity. The olfactory bulb receives the information from the cells and sends them to the Amygdala and the olfactory cortex. The information is then sent to the limbic system from the olfactory cortex. After the information is sent to the limbic system it is sent to the thalamus and onto the orbitofrontal cortex, where the information is processed.

The neurogenic heart of the crayfish will respond to the addition of neurotransmitters and support that there are cholinergic and dopaminergic receptors present.

Decreased interest in olfaction may be related to early work which contrasted varying levels of olfactory abilities among animals, highlighting primates as deficient in this sense. In Turner’s 1891 paper The Convolutions of the Brain, he proposed a classification of Mammalia into three groups 1) Anasmotics, where the organs of smell are absent and included dolphins and whales, 2) Macrosmatics, defined by animals with a highly developed sense of smell and included ungulates, carnivores and most mammals, and 3) Microsmatics where the sense of smell is “feeble” as in pinnipeds, some whales, and apes and man. This idea of apes and humans, indeed, primates in general having a poor sense of smell was corroborated by Negus in 1958 and Le

Senses airborne chemical molecules • Related to memories & emotions • Consists of 10 million rods embedded in the olfactory epithelium – responding to different chemicals

Smells connection to emotion was also discussed, it turned out to be molecules with receptor signals capable of triggering memory through the olfactory part of our brain and the hippocampus, the site of memory

The Radical Addiction The purpose of Bruce Alexander’s experiment was to challenge the beliefs that people have about addiction. He wanted to know if addiction was still a result even when a benevolent environment was present. He wanted to look at the affects social, physical and physiological restrains have on addiction. This experiment’s purpose was to show if addiction was due to the chemical or if it was culture.

On top of the nasal cavity, lies the olfactory epithelium (mucous tissue that covers the cribriform plate and contains the cilia necessary for olfactory receptors). The process starts when air enters the nasal cavity and makes its way to the olfactory receptors. These olfactory receptors are located in the olfactory epithelium and contain many bipolar neurons. These receptors send processes to the epithelium where it divides into 10 to 20 cilia. Molecules of odor then must dissolve in the mucus and stimulate the receptors in the cilia, which detect aromatic molecules. Next, each olfactory receptor cell sends an axon into the olfactory bulb, which is located at the end of the olfactory tract. Here, it forms synapse with dendrites of mitral cells (neurons of olfactory bulb), which takes place in the dendritic and axonal aborizations, called the olfactory glomeruli. From there, the axons travel to the rest of the brain, some terminating in the ipsilateral forebrain and contralateral olfactory bulb.

For the majority of animals on earth, responding to chemical stimuli could mean the difference between life and death. Taste is an example of sensing chemical stimuli-however, this response is not entirely dependent on genes, as tasting something will not necessarily trigger a gene to activate. Within a simpler organism however, such as Caenorhabditis Elegans, there is a complex behavior that is mediated by three sensory neurons and transduce chemical stimuli to move muscles that move an animal forward(attraction) or backwards(repulsion). By placing these organisms on several plates which will inhibit genetic expression, and then testing chemotaxis at a later point, it is possible to determine which genes are responsible for chemotaxis. The global sample averages of the chemotaxis indexes of CEH-36 and CEH-27 are somewhat inconclusive, with a mean of 0.5815 for CEH-36 and 0.6981 for CEH-27. Overall, the results for CEH-27 are likely to show that there is a lack of genetic interference with chemotaxis where CEH-36 is less definitive.

Catnip contains nepetalactone, a terpene. Cats detect it through their olfactory epithelium and not through their vomeronasal organ. At the olfactory epithelium, the nepetalactone is hypothesized to bind to one or more G-protein coupled receptors on the surface of sensory neurons which are found in the sensory layer of the organ. Via a signal transduction

Somatosensation is the collective sense of touch which enables us to feel our environment through the specialized receptors in our skin. While in primates, the glabrous hairless skin of the hand palm and fingers serves as sensory organ to palpate objects and obtain tactile information, rodents use their whiskers, organized in a series of rows and columns on the whisker pad located on each side of the snout (Fig.X). Rodent whiskers acquire somatosensory information by their deflection onto objects in the environment, like the digits of the human, they obtain information regarding their shape, texture and location. Somatosensation is an active process involving sensory/motor systems, where in humans a hand will press an object of interest in order to feel its textile features, the rodent macrovibrassae (whisker) will position itself in space, scanning the environment in a series of timed protractions and retractions cycles (5-10Hz). The interruption of the whisking cycle caused by the contact of a whisker onto an object provide the necessary spatio-temporal information for the construction of a sensory percept. A whisker touch contains numerous information carried out by the amplitude of the whisker deflection, the direction, duration, accelation/decelaration on contact, frequency of the contact, force along the axial shaft and resonance frequency of the whisker.