Chemical Senses

Often, we do not realize just how important our taste and smell senses are to every day life. We go about our day and do the normal human thing. We sleep, eat, shower, get dressed, go to school, work, etc. What if our sense of taste and smell were taken away? How would it change these every day routines? If there were a house fire while we were sleeping and we could not smell the smoke, what would happen? What if we could not taste or smell the food we were eating? What if we could not smell if our bodies were clean when we showered? As a nurse, what if I could not smell a foul odor in regards to urine or

Often, one of the most overlooked of the five senses is the ability to smell. Living things use it every day- from figuring out what the best scent is to eat the most delicious food to figuring out what perfume makes us the happiest (and potentially, the most attractive to others). However, smell is more than just the stench someone gives off. In fact, odor can trigger a variety of emotions. To begin the discussion on the relationship between odor and emotion, one must define what an odor is. More than just a sense, smell consists of molecules that recognized by olfactory receptors and must have a specific concentration (Yantis, 2014). With much research, a relationship between memory and odor has existed and has led to broader findings about odor and other components. According to a 2009 study, a relationship between odor and mood exists (Croy et al., 2011). However, research done regarding odor and emotion is a fairly recent interest and has gained more attention over the last few years. According to the American Psychological Association, an emotion is a “complex pattern of changes, including physiological arousal, feelings, cognitive processes, and behavioral reactions, made in response to a situation perceived to be personally significant” (APA, n.d.).

Smell, on the other hand, is the sense that comes from odor molecules attaching to the olfactory nerve. Air carries the odor into the nose. Then odor contacts the olfactory nerves at the top of the nasal passages. The the olfactory nerves send a signal to the olfactory bulb of the brain, and the nerve sends a signal to the front of the brain. The forebrain translates the signals of the odor into a specific smell (Swindle, Mark).

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 human brain contains specific neurochemical systems that create feelings in us. Over many studies, scientists

Why is it that we tend to remember the thrill of a rollercoaster ride we took at age eight, but fail to remember what we ate for breakfast yesterday morning? Why do we remember falling off our bike and scraping our leg, but not what we got on a fifth grade test? It is safe to say that emotionally significant experiences have a certain salience and are likely remembered more often than not. Differentiating what information we will hold on to and what information we will discard, appears to relate to the emotional impact of a memory or event. Moreover, adrenergic activation appears necessary in order to recall certain information or events. In fact, remembering emotionally arousing material involves noradrenergic activation during or soon

The distinction between conscious and unconscious memory suggests - and it is generally accepted - that emotional memory involves two brain systems. While conscious memory is mediated by the hippocampus, the amygdala is implicated in emotional memory (1). A small collection of nuclei in the center of each temporal lobe, the amygdala controls the fear response, receiving and integrating sensory input to determine the level of threat. If the input is sufficiently intense to initiate an action potential, the amygdala triggers other areas of the brain that induce the physiological response that humans interpret as fear (3); the danger has been "recognized."

The smell receptors interact with the molecules of these vapors and transmit sensations to the brain. We need only a little amount of molecules of substance to trigger an impulse of smell in a nerve end, and we can smell more than ten thousand different scents. If it is a new scent it is possible to remember the scent and identify it again later. The scent captures one’s memory of the place; the nose makes the eyes remember. For the blind people, the sense of smell can help awareness of one’s location. Odour can also relate to hunger and the desire to consume. Since it is not possible to name all the odours, spatial qualities or experiences are often associated with scents. Positive experiences of smell can be used in design to induce positive memories or associations to a space, while negative smells can do the opposite. Bringing certain smells into a designed space can immediately stimulate emotions, guide us, or distract us. Designer Valerie Trent cites research that connects smell and memory; “People can often recall aromas from childhood or a distinctive odor they’ve only smelled once. Whatever your particular nose prefers, smells do enhance comfort and

Scientist has demonstrated that Chemicals regulate various brain functions, so awkward nature in them can influence feelings. Serotonin and dopamine are two chemicals

Two structures in the brain work independently and with each other to impact memory and emotions: the amygdala and the hippocampus. The amygdala is linked to fear-conditioning, while the hippocampus is linked to episodic memories, which are those memories that a person can recall whenever wanted [1]. An experiment was performed to demonstrate the independence of the two structures from each other which involved patients with lesions in the amygdala and patients with lesions in the hippocampus. Researchers designed a fear-condition wherein a blue patch applied to the wrist initiated a shock. They found that patients with lesions in the amygdala had no physiological response to the conditioned stimulus (the blue patch) [2], whereas patients with lesions in the hippocampus demonstrated appropriate

Smell is one of the five basic human senses. Smell is a powerful sense with many abilities. Smell can alert people to potential dangers. Smell brings variety into the world. In addition to these, smell also has one very special ability. Smell can instantly draw memories out of a person.

Although an individual glomerulus may be activated by several odors, the relative levels of activation of several glomeruli differ between odorants. As the concentration of the odorant increases, more glomeruli are recruited to respond; however, the relative pattern of activation is usually maintained for each odorant. Dr. Wachowiak also showed that there is a topographical map in the olfactory bulb such that odorants belonging to a certain class of molecules tend to activate glomeruli in the same area of the bulb, and this map is consistent across animals. Thus, it is possible to study the response to many odor molecules in a large number of animals and collapse the data across subjects to obtain more statistical power. In conclusion, this is an interesting technique that can be used to understand the detailed mechanisms of first-order olfactory perception in live animals. Dr. Wachowiak hopes to continue this research by conducting psychophysical experiments to determine how well the mice discriminate between odors, using genetically encoded probes of neural activity to selectively image certain populations of glomeruli, and studying further steps of processing within the