Drunk Rats Could Overturn Neurological Orthodoxy

By Neuroskeptic | January 14, 2013 10:41 pm

A form of brain abnormality long regarded as permanent is, in fact, sometimes reversible, according to an unassuming little paper with big implications.

Here’s the key data: some rats were given a lot of alcohol for four days (the “binge”), and then allowed to sober up for a week. Before, during and after their rodent Spring Break, they had brain scans. And these revealed something remarkable – the size of the rats’ lateral ventricles increased during the binge, but later returned to normal.

Control rats, given lots of sugar instead of alcohol, did not show these changes.

This is really pretty surprising. The ventricles are simply fluid-filled holes in the brain. Increased ventricular size is generally regarded as a sign that the brain is shrinking – less brain, bigger holes – and if the brain is shrinking that must be because cells are dying or at least getting smaller. So bigger ventricles is bad.

Or so we thought… but this study shows that it might not always be true: alcohol reversibly increases ventricular volume over a timescale of days. It does so, the authors say, essentially by drying brain tissue out; like most things, if you dry the brain out, it gets smaller (and the ventricles get bigger) but when the water comes back to the tissues, it expands again.

As you can see here in Figure 2

Maybe. I admit that just eyeballing this, it looks more like the ventricles are getting brighter, rather than bigger, but I’m not familiar with the details of water scanning. Maybe some readers will know more about it.

If it’s true, this is big – maybe it’s not just high doses of alcohol that does this. Maybe other drugs or factors can shrink or expand, the ventricles, or even other areas, purely by acting on tissue water regulation, rather than by anything more ‘interesting’.

Take the various claims that some psychiatric drugs boost brain volume while others decrease it, just for starters…could they be headed for a watery grave?

Of course, this is in mice – and it might not translate to humans… we need to find out, and I for one am keen to apply for a grant. Here’s my draft:

Participants: 8 healthy-livered neuroscientists.
Materials: 1 MRI scanner, 1 crate Jack Daniels.
Methods: Subjects will confer to pick a Designated Operator, who will remain sober. If no volunteers for this role are forthcoming, selection will be randomized by Bottle Spinning. All other participants will consume Jack Daniels ad libitum, and take turns being scanned. Once all Jack Daniels is depleted, participants will continue to be scanned until fully sobered up (defined as when they can successfully spell “amygdalohippocampal”).
Instructions to Participants: i) what happens in the magnet, stays in the magnet. ii) If you ‘dirty’ the scanner, you clean it up. iii) Bottle caps are not MRI safe!

Er… seriously though, someone should check.

ResearchBlogging.orgZahr NM, Mayer D, Rohlfing T, Orduna J, Luong R, Sullivan EV, and Pfefferbaum A (2013). A mechanism of rapidly reversible cerebral ventricular enlargement independent of tissue atrophy. Neuropsychopharmacology  PMID: 23306181

CATEGORIZED UNDER: animals, fMRI, funny, mental health, methods, papers
  • http://www.blogger.com/profile/12458888593632311541 Char Harr

    I'd like to volunteer for that study!

  • http://www.blogger.com/profile/07429793255785560043 Dirk Hanson

    Alcohol is the most hydrophilic of drugs so doubt you would see this effect with other drugs. Or am I off base?

  • Seth C

    I'd like to see the same study, but with the rats given oral rehydration therapy during the recovery period.

  • http://www.blogger.com/profile/12533263841520213358 William

    A drying out period for improvement of brain drying out in alcoholism… how appropriate

  • Black Book doc

    I hope not many pregnant alcohol craving women read your dangerous post neuroskeptic!

    Back to the old Romans – at least- it has been known for a fact of experiences that drinking a lot of water when binging on alcohol diminuish the hangover. We know now that binging on alcohol causes deshydratation and then your ventricule effect.

    This doesn't make less true that alcohol molecules transforms in a deadly metabolite that just kills gray brain cells slowly but surely alcohol shrink your brain and French psychiatric hospitals are full of alcoholic dementia no amount of fluid will improve!

    Plus, binge drinking is suspected of altering the white brain and is rtespoàpnsable of more suicide that depression itself and of more violent crime than schizophrenia not to couint the traffic casualties.

    By the way,neurosurgeons, decades ago, taught me , not to trust ventricular sizes as a sign of dementia before a person had get proper fluids -and possibly food – in her body for a while on an anorexia nervosa case (who suffered in addition of a brain trauma due to a road accident)

    NB: It would be socialy irresponsible of you if that comment of mine were to met your deleting finger because I spoilt your fun…I am a doctor , you know and have some deontological duties young neurscientists can apparently dispense with.

  • http://www.blogger.com/profile/06647064768789308157 Neuroskeptic

    Black Book doc: You're missing the point; this post is just about an interesting neuroscientific issue, it doesn't say anything about the long-term safety of alcohol, which we know does kill neurons.

  • http://www.blogger.com/profile/06647064768789308157 Neuroskeptic

    Dirk: The authors discuss why it might be, and they argue that maybe it's not alcohol directly that does it, but alcohol-induced reductions in intracellular metabolites (based on MR spectroscopy showing they're reduced); in which case other drugs might do it.

  • http://www.blogger.com/profile/06647064768789308157 Neuroskeptic

    Char Harr: Good, but volunteers might not meet the inclusion criteria: ability to down a pint of beer in 10 seconds or less.

  • Black Book doc

    Dirk

    Catabolic steroid drugs also produce enlarged ventricules which -as in anorexia nervosa and alcohol – might be reversible -at least for a certain period of time.

  • C

    1Not surprising, dehydration will shrink any tissue, and since the brain is inside a fixed volume skull, CSF will fill up any empty space.

  • Bart

    If the brain dry's out, as the author states, would the scans of the surrounding tisseu not become less bright during the binge? The MRI scans speak against him.

    As the choroid plexus gets more circulation by blood veins widening (as happens when consuming alcohol), Does it not automatically produces more CSF? And thereby pressurizing the CSF-system resulting in a headache?

    Just putting out some ideas out…

  • Anonymous

    I like it !

    Would love to see if it still held taking in some seawater, or Elete, my favorite hangover cure.

  • Anonymous

    Thats a pretty useful result. A reduction in parenchymal CSF production causes the choroid production of csf to compress surrounding brain tissue. If that's what we're seeing here, then when the alcohol wears off, the parenchymal production kicks in again and the brain reinflates. If this is happening, it could give a clue as to what causes normal pressure hydrocephalus – i.e. what might reduce parenchymal prodction. Or itmay not. Worth checking.

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Neuroskeptic

No brain. No gain.

About Neuroskeptic

Neuroskeptic is a British neuroscientist who takes a skeptical look at his own field, and beyond. His blog offers a look at the latest developments in neuroscience, psychiatry and psychology through a critical lens.

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