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





Friday, 14 July 2017
Metaphors for the Brain’s Anatomy and Functioning

When I’m making presentations about the human brain to live audiences, the quick, easy method I often use to show them a three-dimensional model of a brain synapse is to hold my two fists facing each other, very close together, but not touching. One fist thus represents the axon of the pre-synaptic neuron, while the other represents a dendritic spine on the post-synaptic neuron. This macro model of a synapse is about 20 centimetres long.

In comparison, a real synapse in a mammalian brain is about 1 micron (one thousandth of a millimeter) long. This estimate includes the terminal button (the swelling at the tip of the axon), the dendritic spine (the swelling on a dendrite of the second neuron which receives the connection from the axon of the first), and the synaptic gap (the space between them). Into this gap, the axon of the pre-synaptic neuron releases its neurotransmitters, which immediately bind to the receptors in the membranes of the post-synaptic neuron’s dendritic spine. (more…)

From the Simple to the Complex | No comments

Monday, 8 August 2016
A Nanometric 3D Representation of a Mouse Cortex Cortex

The analogy between a real forest and a “forest of neurons” has been drawn many times, but the images produced most recently by the team of Jeff Lichtman and Narayanan Kasthuri (see the first two links below) make it clear yet again that the complexity of the brain’s connections far surpasses that of the densest forest.

As Lichtman has long said, by going down to the scale of the electron microscope and then reconstructing the slightest contacts between axons, dendrites, and neighbouring glial cells slice by slice, we can detect patterns that escape us at the more “macro” scales previously used to model neuronal connectivity. (more…)

From the Simple to the Complex | No comments

Saturday, 18 July 2015
Microscopic Synapses and Giant Microscopes

More and more courses are being offered for free online by prestigious universities. Many of these courses deal with various aspects of the cognitive sciences. One such course is “The Fundamentals of Neuroscience”, from Harvard University (see first link below). This course includes various multimedia features, including an excellent 30-minute documentary video entitled “Connectomics: Big Microscopes & Tiny Synapses” (second link below). This video presents the research being done by Professor Jeff Lichtman and his colleagues in his laboratory, who are using images of real human brains to try to map the connections between their neurons—the synapses. (more…)

From the Simple to the Complex | Comments Closed

Tuesday, 27 May 2014
The Variety and Structural Complexity of Neurons

The purpose of most of the posts in this blog is to summarize recent studies in the cognitive sciences and attempt to make them more accessible—in particular by providing links to selected pages on this website. But the purpose of some of the other posts is simply to draw attention to existing resources on various aspects of neuroscience. Today’s post falls in the latter category. It deals with the neuron and the work by Kristen Harris and her colleagues to reveal it in all its complexity (see the first two links below). (more…)

From the Simple to the Complex | Comments Closed

Wednesday, 24 July 2013
Oligomers Help Us Keep Our Memories

A protein whose molecules have the special ability to stack on top of one another, somewhat like egg cartons, and thus form short, highly stable chains (oligomers), may well play a key role in the mechanisms by which we maintain lasting memories.

Indeed, there is always something magical about remembering something that you haven’t thought about in years. But physically speaking, in what form is the corresponding memory trace maintained in your brain over all that time? Neurobiologists know that the whole process occurs in the synapses (the plastic connections between neurons) and have described molecular mechanisms such as long-term potentiation that partly explain this plasticity. (more…)

Memory and the Brain, Mental Disorders | Comments Closed

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