After providing all the funding for The Brain from Top to Bottom for over 10 years, the CIHR Institute of Neurosciences, Mental Health and Addiction informed us that because of budget cuts, they were going to be forced to stop sponsoring us as of March 31st, 2013.

We have approached a number of organizations, all of which have recognized the value of our work. But we have not managed to find the funding we need. We must therefore ask our readers for donations so that we can continue updating and adding new content to The Brain from Top to Bottom web site and blog.

Please, rest assured that we are doing our utmost to continue our mission of providing the general public with the best possible information about the brain and neuroscience in the original spirit of the Internet: the desire to share information free of charge and with no adverstising.

Whether your support is moral, financial, or both, thank you from the bottom of our hearts!

Bruno Dubuc, Patrick Robert, Denis Paquet, and Al Daigen




Wednesday, 7 August 2019
Study on Brain’s Reaction to Social Isolation Argues Against Its Use in Prisons


Why do people who have been intentionally isolated from their peers (for example, prison inmates who have been placed in “disciplinary isolation”) find this experience so completely dehumanizing? We all know that human beings have great needs for social contact. But are these needs so great that simply being deprived of such contact upsets our entire mental equilibrium? If a study published in the February 2016 issue of the journal Cell is to be believed, it would appear that social isolation does in fact lead to genuine impairments in brain function.

Entitled “Dorsal Raphe Dopamine Neurons Represent the Experience of Social Isolation”, this study dealt with a group of neurons in the dorsal raphe nucleus of the brainstem that use dopamine as a neurotransmitter. While doing her doctoral research on the effects of various drugs on these dopamine neurons in mice, the author, Gillian Matthews, unexpectedly observed a strange phenomenon: after a mouse had been isolated from its peers for 24 hours, the connections among its dorsal raphe neurons became stronger.

[Caption: dorsal raphe neurons in mice]

Subsequent research has shown that these dorsal raphe neurons became sensitized during the period of isolation, so that they became highly active as soon as the mice were placed back in contact with one another. And in fact, researchers then also observed high levels of social activity in the mice, correlated with this increased activity in their dorsal raphe dopamine neurons. Using complex but powerful tools of optogenetics, researchers also showed that if they suppressed the activity of these neurons, the increase in social activity following isolation did not occur.

Well, you might argue that these are only mice and that the observed phenomenon does not directly express the distress that they experience subjectively as a result of the period of isolation. But to paraphrase Alcino Silva, who also does research in this field but was not part of this study, it is still fascinating to see that complex emotions experienced by humans, such as loneliness, also seem to be shared in recognizable form by other mammalian species. In any case, that is what the physiological and behavioural changes observed in the mice would strongly seem to suggest.

If 24 hours of isolation can cause such extensive changes in the brains of mice, it is hard to imagine that two weeks of isolation would leave no traces in the brains of such a social species as human beings, who also, by the way, have a dorsal raphe nucleus in their brainstem.

Further research will be needed to determine the exact connections between the dorsal raphe nucleus, social deprivation and the psychological distress that it causes. (For example, does this nucleus detect the isolation, or activate a compensatory behavioural response to it, or play some other role in some broader network in the brain?) But one thing is certain: this study has provided initial evidence about the brain mechanisms that come into play to keep us from being alone, or at least to compensate for long periods of solitude. And one can easily imagine how highly adaptive these mechanisms would have been for our hunter-gatherer ancestors, considering their hard living conditions and the importance that mutual assistance and cooperation have played throughout human evolution.

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Monday, 8 July 2019
Power Weakens Cognitive Abilities To Bond with Other People

This week I’d like to tell you about an article that appeared in The Atlantic in August 2017 and that I’d never gotten around to telling you about before. It was called “Power Causes Brain Damage”, with the subtitle “How leaders lose mental capacities—most notably for reading other people—that were essential to their rise”. The article cites UC Berkeley psychologist Dacher Keltner, whose past work has included studies showing that rich people are more inconsiderate in various situations, such as taking turns with their vehicles at 4-way stops. Apparently, personal wealth provides a feeling of unlimited power that causes rich people to become detached from reality. This finding raises serious questions about the state of mind of the many wealthy people who are elected to represent the people as a whole. (more…)

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Wednesday, 26 June 2019
A communication mechanism in plants that resembles the nervous system in animals

In September 2018, the journal Science published an article with the intriguing title “Nervous system-like signaling in plant defense”. This article describes the discovery of an internal signaling mechanism that some plants use when they are being attacked by plant-eating animals. This mechanism uses glutamate, an excitatory neurotransmitter that plays a well known role in the brains of mammals as well. In these plants, the glutamate molecules bind to a receptor similar to the glutamate receptor in the mammalian brain. By doing so, they increase the concentration of calcium circulating between the plant’s cells (made visible in this photo by means of a fluorescent protein), which warns the rest of the plant that one of its leaves is in the process of being eaten. In just a few minutes, according to this article, the plant activates defense mechanisms to protect its other leaves. (more…)

From the Simple to the Complex | No comments


Thursday, 18 April 2019
Online Game Advances Neuroscientific Research

Five years ago, I wrote a post in this blog about a website called EyeWire, on which Dr. Sebastian Seung and his laboratory enlisted the help of the general public to colour the extensions (axons and dendrites) of neurons on various thin, sequential slices of nerve tissue. The lab then used the results to reconstruct each neuron in 3D on a computer. Today I want to tell you about the Mozak project, which has the same objective of reconstructing neurons in 3D. But where Dr. Seung’s EyeWire project dealt only with ganglion neurons in the retinas of mice, the Mozak project deals with neurons from various parts of the brains of various animals. (more…)

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Tuesday, 19 March 2019
A neuroscientist gets drunk to explain alcohol’s effects on the brain

And that’s not all she does! She also explains the effects of sugar on the body/brain by eating candy, the effects of insomnia by staying up all night, the effects of the flu when she has it herself and even the effects of a break-up by showing how she responds when her boyfriend breaks up with her (or at least that’s what she lets you believe).

The neuroscientist’s name is Shannon Odell, and at the time this blog post was written, she was a neuroscience Ph.D. candidate at the Weill Cornell Medical College of Cornell University, in New York City. In November 2017, she began producing and starring in a series of 5-minute videos called Your Brain On (Blank), in which she explains very entertainingly and accessibly, but with great scientific rigour, just what happens in your brain and your body when you engage in various kinds of behaviours. (more…)

Pleasure and Pain | No comments