Newsflash from 1976: neurons can release more than one neurotransmitter

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Newsflash from 1976: neurons can release more than one neurotransmitter

Neuroscience has a lot of mantras. I blame textbooks.

The concept of “one neurotransmitter per neuron” nicely streamlines any discussion of neuron types. The problem: it’s at best reflection of 80-year-old dogma, and a wild over-simplification. So the fact that evidence to the contrary is rarely found in textbooks should … not surprise you.

The 1930s gave us many things: instant coffee, trampolines, and most relevant to this post, Dale’s Principle, which states that, “the nature of the chemical function … is characteristic for each particular neurone, and unchangeable”. Although this assumption remains the default, co-release of neurotransmitters has been formally discussed (read: published about) since at least 1976. In the past decade, the idea that neurons can release more than one neurotransmitter has gained ever wider acceptance amongst neuroscientists, with the list of brain regions containing co-releasing neurons growing rapidly. 

But what does co-release look like at the level of synapses? And why is there an image from my PhD qualifying proposal in this post?

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Ask a Neuroscientist: On Sleep and Memory

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Ask a Neuroscientist: On Sleep and Memory

Is there any connection between memory and sleep?

Common beliefs are that a good night’s sleep will enhance recall of old and learning of new memories, prevent memories from decaying, and improve insight. But how much of these premises are actually true? Does the right amount of sleep really work miracles when it comes to learning and remembering information? And if so, how can we use these insights in school?

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How to diagnose anterograde amnesia

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How to diagnose anterograde amnesia

How do we tell when someone is experiencing anterograde amnesia?

Anterograde amnesia, refers to the ability to lay down new memories. Persons with anterograde amnesia may not perceive any symptoms, or they may be profoundly confused and disoriented. Kelly Zalocusky describes the symptoms of anterograde amnesia, and explains the differences between this particular type of memory deficit, and another common form, dementia. 

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Ask a Neuroscientist: Auditory Hallucinations

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Ask a Neuroscientist: Auditory Hallucinations

Why can we hear music that isn’t really there? Dr. Luke Parkitny discusses how this question gnaws at some fairly complex and incompletely understood neuroscience phenomena. He explains how: "At the core of auditory hallucinations lies a breakdown in how signals from the outside world are translated into experience. ... In a sense, the world of musical hallucinations is one that is dominated by memories and predictions that are untempered by reality."

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Ask a Neuroscientist: The Limits of Handedness

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Ask a Neuroscientist: The Limits of Handedness

Can training over come innate ability? 

Whitney Ellen Heavner answers a question from a competitive video gamer who asks whether his reliance on his non-dominant hand puts him at a biological disadvantage to other players. Whitney discusses how fine grained handedness really is (do you have right/left preference at the level of individual fingers?), and whether all types of motor movements are affected by handedness bias. 

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Ask a Neuroscientist: What is the origin of psychopathology?

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Ask a Neuroscientist: What is the origin of psychopathology?

What is the origin of psychopathology? What do neuroscientists and psychologists today think of early efforts [by classical schools of psychoanalysis]? Why isn’t there a paper out there today entitled “The neural basis of Freudian repression of primitive drives”?

In this Ask a Neuroscientist, Becca Krock discusses Freud's efforts to link fundamental psychological phenomena with his cutting-edge knowledge of the brain, and the modern research that has followed in his footsteps.

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Ask a Neuroscientist: A Spectrum of Handedness

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Ask a Neuroscientist: A Spectrum of Handedness

Are you left handed? Right handed? Somewhere in between? 

What is commonly thought of as "left" and "right" handedness, is probably more accurately described as a spectrum. Where we lie on that spectrum (from strongly right handed, to strongly left handed) can depend on the task we are performing. For example: you might be strongly left handed when it comes to writing, but you find it more natural to open a jar with your right hand. Or when you open the lid of a hinged box, you do so with either left or right hand. 

We don't really have a good handle on what it is about the brain that makes us handed (or footed). But we do know that other animals also show similar preferences. So it's possible that handedness is some kind of fundamental feature of the way brains generate movement, and interface with muscles. 

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