j *@ - Sociedade Brasileira de Psicologia

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memory trace lasting longer than 24 hours (Bittermnnn etal.- 1983; Erber etal., 1980;
Menzel, 1987 ; Menzel et aL,' 1974). ' '
The time course of the memory after a single learning trial reflects > biphasic
structm e. Shortly after a single learning trial the conditioned response is high, a few
ml'nutes later it is reduced to less than half of the initial value, and then conditioned
responding rises again dlzring the next 10-15 mins (consolidation). In order to form a
life-long stable memory, a minimltm' of 3 learning trials are required.
The initial memory trace is erased by varjous experimental procedmes. For
eMmple, the time course of retrograde nmnesia induçed by cooling (+1Oc) of the
whole animal or by weak electrostimulation of the brain indicatis a susceptible
memoiy of a few. minutes following a single liarning tyial, Whereas rapid repetition of
learning trials ienders the memory trace immune to amnestic treatments within a very
short tkne. '
In my oral presentation 1 disclzssed the folowing questions: '
1 . How do the non-associative and the associative components contribute to
the dynamics of the memory trace?
2. ' Do the early, median and late phases of memory occupy the same or
ifferent neuropils in the bee brain?
3 * Aie the memory phnKes arranged in sequence or is there paralil access . to
the median-late phase of memory?
J . 4. . Is the content of memory the same in its early and later stages?
. . . .
.
Noneksociative and associative components
stimutation of the antenna with a drop of sucrose solution of a harnassed
bee calzses the reflexive extension of the tongue (proboscis) and the preparation of the
nnimal to search for and suck up the sucrose solutkon. The US (sucrose stimulation of
.
the alitennb aild/or proboscis) is a strong jtimulzs, and it is thus worthwh j. e asking
what changes on the response probability are induced just by the Us (sensitization
effect of the Us alo'ne). I prelented an experiment showed the timeeourse of fesponse
pro bability to a puff of odorant for 4 conditions: 1 or 3 pairings of CS and US under
b ptimal
tim' e conditions for associative learning , and 1 or 3 stimulations with the US
alùne. A total ùf 1200 nnim' als were tested in 36 simultaneously tested experimental
groups; each anim àl was tested only once after sensitization or conditioning at a
cerinin interval. The çone trial conditioning group' shows the biphasic time course
with the ionsolidation between 3-10 min and then the reduction at long time intervals;
3 CT's also initiate a slight and prolonged consolidâtion and no reduction at long time
intervals. 'l'he sensitization trials catkse an enhanced response level only in the very
' ' f'trst 2 mlnutes an d a very sm al in' crease wltich is inost likely due to an Mcreasing
'
hunger motivation (the animàls are not
fed 'throughout ihe whote experiment). Most