bee learning in Nature

[jonathan_beard]

entomology
Findings about bees' brains could shed light on how people learn


URBANA, Ill. - Can honey bees help scientists understand how adult
humans learn?  Researchers at the University of Illinois are convinced
they can.
In the July 15 issue of the journal Nature, they describe structural
changes that occur in the brains of bees when the insects leave their
domestic chores to tackle their most challenging and complex
task - foraging for pollen and nectar.
As part of a doctoral thesis, neuroscience graduate student Ginger S.
Withers focused on the "mushroom bodies," a region of the insect brain
so named because it appears mushroom-shaped when viewed in
cross-section.  The region is closely associated with learning and
memory.
Withers used quantitative neuroanatomical methods to study sections of
bee brains to show that the mushroom bodies are reorganized when a bee
becomes a forager.  Although a honey bee typically switches from
hive-keeping tasks, such as rearing younger sisters and caring for the
queen, to foraging at about three weeks of age, the brain changes are
not simply due to aging.  In a key experiment, young honey bees were
forced to become foragers by removing older bees from the colony.  The
mushroom bodies of the precocious foragers, who were only about one
week old, mirrored those of normal-aged foragers.
The findings suggest that nerve cells in the mushroom bodies receive
more informational inputs per cell as the bee learns to forage.  In
order to be a successful forager, a bee must learn how to navigate to
and from its hive and how to collect food efficiently from many
different types of flowers.
The implications for neuroscience go far beyond the beehive, said the
article's co-authors, U. of I. insect biologists Susan E. Fahrbach and
Gene E. Robinson.  There could be application to human studies, they
said, because the structure of bee brains is similar to - but much
simpler than - human brains.
Fahrbach, whose research has focused on the impact of hormones on the
nervous system, was drawn to the honey bee by its sophisticated
behavior, small brain and power of concentration.  "Honey bees offer
an exceptionally powerful model for the study of changes in the brain
related to naturally occurring changes in behavior, because, once a
bee becomes a forager, it does nothing else," she said.  "Because the
behavioral shifts are so complete, the changes in brain structure that
accompany the behavioral transitions must be related to the
performance of the new observed behavior."
Robinson, who is director of the U. of I.'s Bee Research Facility and
who has previously studied other physiological and genetic aspects of
bee behavior, agrees:  "This discovery opens a new area of research on
the relationship between brain and behavioral plasticity.  One
fundamental question this research raises is 'which comes first?'  Do
changes in behavior lead to changes in brain structure?  Or do the
changes in brain structure occur first, in preparation for the changes
in behavior?"
As researchers pursue the changes in brain cells that form the
underpinnings of learning, the
U. of I. scientists say the combination of neuroscience and entomology
may yield sweet rewards.

Contact:  Jim Barlow
University of Illinois News Bureau
phone: 217-333-5802   fax: 217-244-0161
Compuserve:  72002,630
Internet:  jbarlow at ux1.cso.uiuc.edu