Huntington’s disease (HD) is a neurodegenerative disorder that slowly diminishes one’s ability to walk, talk, and reason until eventually control is completely lost. HD is an autosomal dominant genetic disorder, so everyone who carries the gene is guaranteed to develop the disease and will have a 50% chance of passing it on. Currently, there is no cure for this devastating disease, and most die within 10-20 years after onset.
With no treatment or way to stop the progression of HD, the outlook of those diagnosed has seemed pretty bleak. Until now. A new clinical trial for an HD drug is set to enter Phase 1 in 2015. This drug is meant to target the source of HD itself: the Huntington gene.
Neurogenesis occurs in two areas in the human adult: in the dentate gyrus of the hippocampus and in the olfactory system. The hippocampus is vital to learning new information and memory consolidation, thus it makes sense that new neurons need to be born in that region. The olfactory system is needs neurogenesis to process to new information. Majority of neurogenesis actually occurs during prenatal development. In fact humans initially have more neurons that necessary for survival. Apoptosis (programmed cell death) occurs to prune the synapses established during early development.
Many studies have been conducted that investigate ways to increase neurogenesis. Such activities include voluntary physical exercise or being in enriched environments. Experiments with rats have shown that being in an enriched environment where rats are exposed to complex objects, toys, running wheels, etc. spark improvements in performance of tasks measuring levels of learning and memory. For humans, I suppose an enriched environment could be a place involving novel stimuli or
If you think about it, how could neurogenesis be bad? I mean people with neurodegenerative diseases suffer from the consequences of neuronal loss, right? However, according to a study published in May 2014 in Science, exercise could induce amnesia. An article regarding this study states, “Adult mice that exercised on a running wheel after experiencing an event were more likely than their inactive mates to forget the experience.” Thus it appears that the neurogenesis that occurs during exercise may be “wiping out” neurons that encoded previous memories. Furthermore, when neurogenesis was pharmacologically inhibited scientists observed a recall failure in the rats. This article relates this phenomenon to the fact that children cannot form long term memories until they are 3-4 years of age.
Despite controversy about neurogenesis, olfactory ensheathing cells (OECs) have been used to help a paralyzed man walk once again. An article published in October in BBC News describes how doctors in Poland accomplished this feat. The first step to this process was to extract cells from the patient’s olfactory bulbs (they removed one olfactory bulb and grew the cells in culture). Two weeks later the cells were implanted in the areas surrounding the spinal cord damage the patient had experienced. This action allowed the spinal cord cells to regenerate because the nerve grafts acted “as a bridge to cross the severed cord.” The implications of this type of surgery are pretty amazing – it could work wonders for paralyzed veterans/other individuals and people dealing with dysfunctions relevant to spinal cord damage.
Exercise Can Erase Memories – The Scientist
- Srijesa K.
Nothing is better than satisfying a craving for junk food. Be it Oreos, chips, or chocolate, digging into your favorite snack is probably the best feeling in the world. But what happens when junk food stops becoming a guilty pleasure and instead becomes a real addiction?
Research has discovered that sugar is more addictive than cocaine and that your brain becomes addicted to its own release of opioids in the reward system. The reward system in our brains evolutionarily benefited us by rewarding us for engaging in behavior that encouraged our survival. Thus, when we eat, the neurotransmitter dopamine (usually associated with happiness and pleasure) is released, causing the happy feeling you get when you satisfy a craving.
The world that we live in is one of easy access to sugar-rich foods and has lead to the normalization of overly sweet and processed foods in our everyday lives. Just like any addiction, tolerance to a substance may occur. In this case, constantly activating the reward system and releasing dopamine by continuously eating junk food can cause dopamine receptors to down-regulate. At this point, dopamine receptors are removed by the brain to maintain a balanced state. Fewer dopamine receptors prevent the same stimulation/effect created by dopamine release; thus we tend to eat more junk food to reach the same level of pleasure as before.
Do you ever think about your childhood or replay an event in your head that happened 15 years ago but its so vivid that it seems like it happened yesterday? Do you ever hear something and think it sounds like your favorite song and then start singing that song? These are memories that were formed in your brain that are replayed as a result of a specific stimulus. For a long time scientists believed that memories were formed, processed, and sent to different destinations in the brain. Dr. Wilder Penfield was one of the first to accidentally discover this. In the 40s he electrically stimulated different areas of his patients’ brains while they were under local anesthesia and found that the region he stimulated would elicit specific memories in the patient’s life (see video below). For example, in one of his patients he stimulated her temporal lobe (auditory cortex) and she started to hum her favorite song out loud. This suggested that the memory of this song was stored in the place where it was processed or originated (i.e. the auditory cortex processed the first time she listened to the song). Penfield concluded that the cortex (the outer layers of the brain) stored the “complete record of the stream of consciousness; all those things in which a man was aware at any time…” Until recently, scientists have believed this phenomenon.
Sensory Processing Disorder(SPD) is a disorder that impairs processing of sensory information in the brain. For children it can cause klutziness, an inability to properly orient the body, poor fine motor skills, and a hypersensitivity to sound. In summary, this disorder makes it very difficult to process incoming information. The condition is very common for children and often is not properly diagnosed because until recently, there had not been a real biological explanation for the disorder. A very common treatment for these patients is occupational therapy.
We all feel scared, jumpy, or anxious but have you ever stopped to think why? Have you ever wondered why you get those goosebumps or why you feel that you are frozen sometimes? Just in time for Halloween, here is some information on how our body processes fear. According to NIMH, fear is defined as a feeling of disquiet that begins rapidly in the presence of danger and dissipates quickly once the threat is removed and is also generally adaptive. Fear is a primitive response.
While neuroscientists do not understand the pathways that we take to interpret fear, there are a few recent studies that examine this. In the first one, scientists identified specific neurons called SOM+ that are linked to a type of “fear memory” held in the amygdala.
Stockholm Syndrome can be referred to as a joke in the popular culture, and many people do not take it seriously as much as other common psychiatric problems such as PTSD, a psychological illness usually caused by a traumatic event like physical aggression. It cannot be treated seriously because there is no medical standard to properly diagnose a person with “Stockholm Syndrome.” However, this supposed illness is a real problem that affects the minority of people who are abducted usually by criminals who have no interest in the hostage’s safety.
The first recorded case of hostages with Stockholm Syndrome was during a bank robbery in Stockholm, Sweden. In August 23 to 28, 1973, the bank robbers negotiated with the police to leave the bank safely. While trying to form an agreement, the majority of the captive bank employees were unusually sympathetic towards the robber, and, even after being set free, refused to leave their captors. The criminologist and the psychiatrist who were investigating the robbery coined the term for their conditions “Stockholm Syndrome.”
What is music? It’s something I listen to when I want to relax or when I want to focus. If I’m missing home, I listen to Bollywood. When it’s Christmas, I listen to carols, both classic and modern. So clearly, I think of music as a source of entertainment. In fact, in both ancient and modern times, music has been a key component of celebrations, like weddings and cultural events. Interestingly, scientific research on music and the brain has shown that music has more benefits than entertainment alone.
Not one for sour food? Look no further than miracle berries – the fruit of the shrub Synsepalum dulcificum – to turn sour delicacies into sweet treats. A New York Times article reported the drastic changes in the taste sensation that consumers experienced after eating these berries. A tart concoction of lemon sorbet and Guinness tasted like a chocolate milkshake, a drizzle of tabasco sauce could have been mistaken for donut glaze – just one berry is enough to turn your taste buds upside down.
This miracle is achieved by the appropriately named miraulin, a glycoprotein contained in the fleshy portion of the berry. It binds to taste receptors on the taste buds, and for the most part does not affect taste sensation. However, when sour foods are consumed, the acid contained lowers the pH in the mouth. The miraculin on the receptors binds to the protons released by acidic substances, activating sweet receptors. It has been suggested that it changes the structure of taste receptors on the tongue, but any evidence towards this has been inconclusive. It is interesting to note that miraculin itself is not sweet.In fact, the berry has very little sugar.
Imagine you’re on your first date and you and your partner are hitting it off big time. It’s probably his/her witty comments or good sense of humor, his/her intelligence or impeccably beautiful smile that makes you feel extremely attracted to your date. As time goes on, you look deeply into each other’s eyes and giggle. You wonder, “am I falling in love?” The answer is: probably not (you’re only on your first date here, come on). You may not be falling in love, but you are feeling a stronger and closer bond being formed; and you’re feeling this way with some help from the hormones norepinephrine, dopamine, and oxytocin.
That’s right, kids– everything your parents told you about your crazy hormones when you had “The Talk” is true. Your hormones really are going crazy, and they really are helping you feel the way you do. When in love, areas in the brain that are known for their dopamine and norepinephrine production light up.