Fight or flight gets joined by f—, pee, & poop

Just a few days ago, I wrote a post about a very unusual occurrence: a serious change in a fundamental piece of neuroanatomy. To recapitulate, Jean Francois Brunet and his colleagues, including lead author Isabel Espinosa–Medina, used a modern molecular approach to show that the autonomic motor neurons in the sacral cord share their characteristics with the sympathetic motor neurons in […]

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A revolution in Neuroanatomy!

There has been a revolution in the unlikeliest of disciplines! Neuroanatomy! Yes neuroanatomy – so cut and dry – has been seriously altered by new research. The textbook world of neuroanatomy turned upside down yesterday. A team led by Jean François Brunet of INSERM in Paris has made the audacious proposal that the autonomic outflow of the sacral cord is […]

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Persons not vegetables: Dead, alive, and the in-between

Once upon a time there was dead and there was alive. The twain did not meet nor intersect outside of religious miracles. The era of dead-or-alive lasted for millennia until the 20th century when technological advances inserted an in-between state that consisted of alive only because of medical assistance. The first crack in the dead-or-alive edifice started with ventilators, machines that […]

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Journeying into the sheep brain

In this installment of laboratory videos, the goal is to compare the sheep and human brains. What we’ll see is the extreme similarity in the basic plan of the sheep and human brains. This is part of our mammalian inheritance, the common evolutionarily derived template that mammals share. In this first video, we look at sheep and human brains side by side and identify the major brain regions in each. Now let’s go inside the sheep brain. The first important point is to see that, as in the human, the telencephalon arches over the diencephalon and brainstem in the sheep. And while the human telencephalic cap covers even more of the rest of the brain than does the sheep cap, the sheep telencephalon is no small potatoes. In fact, the telencephalon is impressive even in smooth-brained (= lissencephalic or lacking sulci and gyri) mammals such as the rat that have relatively small cerebral cortices. By looking at sheep brains, I discovered something surprising; namely that the sheep superior colliculus appears larger than the human superior colliculus. I mentioned this in NeuroMOOC class and several students began to discuss this issue. These clever NeuroMOOCers came up with two intriguing ideas regarding how a large colliculus might render a behavioral or ecological advantage to sheep. First, the sheep with its laterally placed eyes has a wider visual field than does the human with its forward-facing eyes. The sheep can see close to […]

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