hi all

more confirmation of our miraculous (if temporary) homes

it seems to me that i posted a news item a couple of years ago
reporting that one spot in the brain is in charge of naming things

i love new news!

janet

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Study gives clues to how the brain moves the body

NEW YORK (Reuters Health) - New research in monkeys is shedding light on
how the brain controls the body's movement--suggesting that single spots in
the brain govern actions far more complex than previously thought.

It is known that a brain's motor cortex contains a "map" of the body that
is used to control movement, but the exact role of this area in performing
movement is unclear.

Whether the otor cortex is primarily involved in muscle control or
"higher-order" control of movement--such as direction and trajectory--is a
central question.

In the new study, researchers at Princeton University in New Jersey found
that electrical stimulation of particular sites in monkeys' motor cortex
caused the animals to take on complex "postures" - such as coordinating the
arm, hand and mouth into an "eating" stance - as opposed to initiating
simple muscle contraction.

This is in contrast to the "traditional" view that each location within the
motor cortex controls only a muscle, according to the study's lead author,
Michael S.A. Graziano.

In this view, if you stimulate a given spot in the cortex, then the single
muscle it governs contracts, he told Reuters Health.

This would also mean that another part of the brain must be in charge of
tapping the right spots in the motor cortex to execute movement.

But, Graziano said, "our results show that the motor cortex is not a
look-up table of muscles.

"Instead, each spot in the motor cortex corresponds to a complex,
coordinated motor act."

In his team's research with monkeys, such complex acts included bringing a
gripped hand to the mouth as if eating food, and bringing the hand near the
face while turning the head away, as if for protection.

"The fact that a single spot in the (motor) cortex can represent such a
complex part of the animal's repertoire is new and totally unexpected,"
Graziano said.

The findings are published in the May 30th issue of the journal Neuron.

Dr. Richard J. Krauzlis, who wrote a commentary accompanying the report,
agreed that the study suggests that stimulating the motor cortex "elicits
postures that are far more complex than would be expected based upon
current thinking."

Krauzlis, a researcher at the Salk Institute for Biological Studies in La
Jolla, California, told Reuters Health that understanding how complex
movements are generated is important for human health.

He pointed out that various nervous system disorders - including stroke and
Parkinson's disease - involve problems with motor control.

"Understanding the basic mechanisms underlying motor control is therefore a
crucial step toward developing therapies, if not outright cures, for these
nervous system disorders," Krauzlis said.

SOURCE: Neuron 2002;34:673-674, 841-851.
Last Updated: 2002-05-30 10:00:34 -0400 (Reuters Health)
By Amy Norton
Copyright 2002 Reuters
http://www.reutershealth.com/archive/2002/05/30/eline/links/20020530elin005.
html

janet paterson: an akinetic rigid subtype, albeit primarily perky, parky
pd: 55/41/37 cd: 55/44/43 tel: 613 256 8340 email: [log in to unmask]
smail: 375 Country Street, Almonte, Ontario, Canada, K0A 1A0
a new voice website: http://www.geocities.com/janet313/

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