Lobsters, Axons, Telephones, and Extracellular Recordings – A look at how neuronal signals can be transmitted differently under certain pharmacological conditions.
Neuronal signals are normally transmitted from cell bodies, or somas, to terminals via extensions called axons. At these terminals, connections called synapses are made with other neurons whereby the signals are released via the aide of chemical messengers called neurotransmitters. Many still believe that axons are reliable conductors of these signals.
However, with several years’ worth of experiments, scientists have questioned the fidelity of axonal conduction. They’ve realized that axons do not work like telephones. While telephones and axons may both have buttons – at the terminals in axons – only telephones faithfully conduct signals. And only telephones ring aloud and send messages to voicemail…
In any case, neuronal signals, unlike telephone signals, can change along their paths. Moreover, the pre-synaptic neuron may communicate a different message from the one originally sent from the soma to the synapse with the post-synaptic cell. Researchers at the lab I’ve been working at this summer, the Whitney Laboratory for Marine Bioscience, have focused on the role of neuromodulation in signal transmission along axons, particularly by the well-known neurotransmitter – dopamine. More
You’re lying on a sandy beach on a hot sunny afternoon, enjoying a few hours of much needed laziness. As you open your eyes and confront the vastness of the ocean in front of you, light of 600nm wavelength hits your retina, kindling an impossibly long cascade of events in your brain: a molecule called retinal changes shape, neurons fire action potentials down the optic nerve, arrive at the lateral geniculate nucleus deep in the brain causing more action potentials in primary visual cortex in the back of your head, and so on ad infinitum. At some point, the mechanical wonder of 100 billion neurons working together produces something special: your experience of the color blue. What’s special is not that you can discriminate that color from others; nor that you are aware of it and paying attention to it. It is not notable that you can tell us about it, or assign a name to it. It’s that you have a subjective, qualitative experience of the color; there is something it is like to experience the color blue. Some philosophers call these experiences qualia – meaning “what kind” – but it is not important what kind of experience you are having, just that you are having one at all. Modern science hypothesizes that subjective experience is a product of the brain, but has no explanation for it. More
Using the human nervous system as a representational medium, are there parts of the universe that are innately unknowable to us- are there realities that we can experience but not objectively measure? Is spirituality real, or a man-made delusion to justify ambiguous emotions and guide behavior? Is consciousness an emergent property or does it extend beyond?
These are timeless ontological questions that have been posed by both philosophers and the common man for centuries. But only recently has the new field of neurotheology, the study of correlations between neural phenomena and subjective experiences of spirituality, emerged on the scene to advance our understanding of what the brain undergoes during religious practices. Whereas before we could only rely on logic and speculation in an attempt to tackle some of these controversial issues, today neuroscientists are beginning to uncover substantial information regarding the relationship between brain activity and “the feeling of God”.
Scientists have long been intrigued by claims of mystical encounters. Though these assertions may seem to be all too uncommon and even downright outlandish in an increasingly “secular” nation, still a survey by the Pew Form on Religion and Public Life demonstrated that nearly half of American adults today have had what they consider a “religious” or “mystical experience” of some kind. In order to investigate the biological basis of these obscure episodes, scientists first explored the effects of psychedelic drugs, which have a long history of traditional use in religion. Since users of psychedelics often report of the drug’s ability to elicit a sense of the spiritual, as well as promote mental healing, researchers sought empirical support for the notion that psychedelic drugs could facilitate “religious experiences”. More
Free will is a hackneyed topic. Science seems to be telling us that free will doesn’t exist because behavior is governed by the brain and the brain operates on physical rules of cause and effect. There is no such thing as uncaused cause, which free will requires. For some people this is an unbearable notion; these folks hang on to their perceived volition as evidence that they are in fact free to do as they choose, without being constrained by their biology. Others swallow what science has espoused long ago; of these folks, some tend to be pessimistic, thinking that their lack of free will means that everything is pointless and that the best thing they can do for themselves is to blur the line between their behind and a comfortable couch, until scientists discover the new species Homo sofus. More
Ranging from the Eastern Mediterranean in the 7th century, to China in the 16th century, and finally to Europe in the 17th century, dream interpretation has been viewed as a decryption of supernatural communications and symbolic messages. Sigmund Freud, the academically (in)famous founder of the field of psychoanalysis, whole-heartedly supported the hypothesis that dreams contain deeper meaning. He consequently produced one of the seminal works on the subject, quite obviously named, The Interpretation of Dreams. Today, revelatory and efficient techniques, such as MRI and EEG, have far surpassed Freud’s interpretive dream journal methods, and allow scientists to look at dreams from a very different perspective. Although these advancements lend more credibility to the field of oneirology, it is still somewhat tainted by its psychoanalytic past. Some even go as far to say that studying dreams is “academic suicide”. Nevertheless, modern neuroscience has forced Freud’s ideas to the background, making room for new theories of memory consolidation, experience organization, and emotional stabilization.
Since dreaming occurs while sleeping, it is no surprise that the sleep cycle, during which the brain experiences patterns of varying electrical activity, has been implicated in dream theories. Each cycle consists of five stages – two stages of light sleep, followed by two stages of deep sleep, and completed with a stage of rapid eye movement sleep (REM). Unfortunately, there is no representative electrical pattern associated with dreaming, but REM and non-REM sleep have both been connected to the brain’s analysis of waking experiences. Pierre Maquet at the University of Liege, Belgium, observed deep non-REM sleep and found that the brain’s electrical activity mimicked the electrical activity elicited during waking experiences.
Not only do we replay events in our dreams, but we also seem to process, integrate, and store the information for future use. Robert Stickgold of Harvard University found that those who had non-REM dreams about a task that they were asked to complete, proceeded to do better on it. Stickgold proposes that “non-REM dreaming might be more important for stabilizing and strengthening memories, while REM dreaming reorganizes the way a memory is stored in the brain, allowing you to compare and integrate a new experience with older ones”. On a different, albeit related note, daydreaming activates a part of the brain called the default network. This region has previously been shown to be associated with memory processing. Be sure to mention this to your professor next time you’re caught not paying attention in class.
Matt Walker of the University of California acknowledges that dreaming has an important role in memory, but argues that the main function is emotional homeostasis. Walker has found that REM sleep facilitates the strengthening of negative memories. He believes that experiencing the negative emotion in a dream state can diminish the intensity of the emotion, making it easier to deal with. In those with post-traumatic stress disorder, however, this process seems to fail. Boston University’s Patrick McNamara agrees with Walkers’ speculation. He believes that “non-REM dreams help us practice friendly encounters, while REM dreams help us to rehearse threats”.
While dreaming, the brain rewires itself and forms new connections. It seems that this curious kind of consciousness does not reveal our secret desires or open windows into our hidden selves, but instead plays an integral role in making us who we are. Sorry, Siggy.
To view the original article from New Scientist, click here!
Here are two more renditions of shirts for BU Neuroscience. Please VOTE!!
Psych Central’s April Fool’s Day Joke for 2011 was an article that read: “Facebook Revealed to be Psychology Experiment Gone Wrong.” The author used a fake source of Harvard University and several quotes from ‘professor of psychology’ Mark Zuckerberg. This article seemed pretty believable…for about a day.
The researchers behind this project claimed to be interested in “whether or not people in the class would immediately become competitive and try and gain as many friends as possible.” And though this research experiment is far from the truth, the psychological implications of Facebook are certainly a reality.
Rishi Bandopadhay of PsyBlog equated Facebook networking to a competitive sport. He listed 7 rules to ‘get ahead’ using Facebook.
- Get between 100 and 300 friends. (You don’t want to look like a loner, or like you are trying too hard)
- Court attractive friends (Walther et al. (2008) found that attractive friends boosted the perceived attractiveness of participant’s profiles)
- Understand the 7 motivations (Joinson (2008) found 7 basic motivations for using Facebook: connecting with old or distant friends, social surveillance (see what old friends are up to, but without talking to them), looking up people met offline, virtual people watching, status updating and content)
- Don’t let your partner use Facebook (Muise et al. (2009) found that the more time spent on Facebook, the more jealousy)
- Guard your privacy
- Display your real self
- Use Facebook to get a job
Is Facebook really this competitive? I can’t remember the last time I noted how many Facebook friends someone had or judged their popularity by their friends’ good looks. Facebook can also tell you a lot about someone’s personality.
Buffardi and Campbell of the University of Georgia found that individuals’ level of activity on their social networking website is strongly correlated to their level of narcissism; this finding is relatively obvious. It’s easy to see which friends of ours, whose ‘activities’ constantly show up on our newsfeed, are self-centered.
Next Orr, Sisic, Ross, Simmering, and Arseneault set out to study correlations of shyness to various aspects of social networking websites. They found that shy people spend considerably more time on Facebook than people who are not; however, these shy people also had considerably fewer friends, despite their increased time spent on Facebook. So the quiet kid who sits in the back of your Statistics class has probably Facebook stalked you, but you’ll never be receiving a friend request because that person does not have the guts to hit “Send Request.”
Psych Central- Facebook Revealed to be a Psychology Experiment Gone Wrong
PsyBlog- Facebook: 7 Highly Effective Habits
The Layman’s Guide to Psychology- The Psychology of Twitter, Facebook, and other Social Networking Devices
Biological systems, such as the circulatory, respiratory, and nervous systems, are groups of organs that function together to perform a common task. Some can also participate in crosstalk with other organ systems. The respiratory system, for example, brings in the oxygen that the circulatory system delivers to all the cells of the body, and maintains blood pH. The endocrine and nervous systems are signaling systems that facilitate communication between different parts of the body by use of hormones and neurotransmitters, respectively. These connections are numerous and complex, but it was previously thought that the immune system and the nervous systems were separate and largely autonomous.
In June 2010, Mauricio Vargas and colleagues from Stanford University School of Medicine reported research in Proceedings of the National Academy of Sciences showing that endogenous antibodies play an important role in repairing peripheral nervous system (PNS) damage. Antibodies are a principal part of the adaptive immune response to infection, but this research suggested that antibodies are also able to clear degenerating myelin which inhibits axon regeneration, akin to a homeostasis function. This repair was only present after PNS injury, whereas myelin debris remained in the central nervous system (CNS) white matter for years. The well known blood-brain barrier concurs with this separation in responses, as it is understood to be impermeable to large proteins such as antibodies.
Sammy Maloney was a happy and outgoing 12-year-old boy. In 2002, however, his mother started to notice curious deviations in his personality. In six months, he underwent complete mental deterioration and was diagnosed with obsessive compulsive disorder and Tourette’s syndrome. Shortly afterwards, he was found to be harboring a streptococcal infection, although he exhibited no physical symptoms of one. Interestingly, when he started taking the prescribed antibiotics, his behavior markedly improved.
Madeline Cunningham at the University of Oklahoma has spent several years investigating various behavioral disorders associated with streptococcal infections. Cunningham has shown that antibodies against one group of streptococcal bacteria are able to bind to a site in the brain that controls movement, and consequently trigger the release of dopamine. This could explain the emotional disturbances associated with these types of disorders (1).
Studies also suggest that an activated immune system has other perceivable effects on the nervous system. For example, Jonathan Kipnis of the University of Virginia and his colleagues have shown that learning triggers a stress response in the brain, which causes CD4 cells, a type of T lymphocytes, to gather at the meninges and release interleukin-4. IL-4 switches off the stress response and causes a release of brain-derived neurotrophic factor, which facilitates memory formation. Interestingly, cancer patients treated with chemotherapy drugs often experience various cognitive defects and some memory loss. This is commonly called “chemobrain”, and these studies raise the possibility that it is a consequence of immunosuppression. Finally, an immune response against Mycobacterium vaccae has been shown to improve mood by causing neurons in the prefrontal cortex to release excess seratonin.
So it could be that the blood-brain barrier is kind of leaky after all. Understanding the connections between the immune system and the brain could lead to all sorts of ingenious treatments for various disorders. Perhaps those scientists at Stanford will utilize antibodies to develop a treatment for central nervous system repair. Perhaps we’ll one day be faced with immuno-emotive treatments for depression. Who knows? Anything is possible when a long-standing “truth” turns out not to be absolute – I’m optimistic since scientific advancement is often built on the refinement of prior knowledge.
Happiness is Catching – New Scientist
Endogenous Antibodies Promote Rapid Myelin Clearance and Effective Axon Regeneration after Nerve Injury – Proceedings of the National Academy of Sciences
(1) Antibodies raised against the Streptococcal M protein and human myocardial tissue, and Guillain-Barre syndrome in response to Campylobacter infection, are well studied examples of cross-reactivity between anti-pathogen antibodies with host tissues.
The neuroscience of addiction has been extensively studied, giving priceless insight into what is happening in the addict’s brain and what keeps people hooked on drug-seeking behavior. Most of the research, though, has been all about the chemical changes in the brain, delving into the molecular level of receptors, neurotransmitters, and reward pathways, etc. But a new approach is being taken from research focusing on extended applications of neuroscience, such as linking neuroscience and “social research and communication studies.” In this video, primary researcher Emily Falk explains the work that is being done at the University of Michigan to try to use the brain as a More