j *@ - Sociedade Brasileira de Psicologia

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NA and OA have similar facilitatory effects on memory formation. NA
increases the number of conditioned responses when injeded into the alpha-lobes
and calycis but not in Ped. OA also enhances the probability of CR, but in the Ped.
and not in the alpha-lobes. Synerphline application into the Ped. induces the enhancement
of memory retrieval. Phentolamine, a competitive alphaz-adrenoreceptor blocker
and also a wel known OM antagonist injected into the Ped. shows the inhibitor
effects both in memory storage and retrieul. If Yohimbin (alphaz-adrenersc
antagonist and also OA1 blocker) (15) is applied into the Zpha-lobes in m lnhroom
bodies, neither mem ory formation nor retrieval influences are fotmd. However,
Yohimbin reduces the CR in the storage test when this test solution is injeded into the
m d. These data lead us to believe that Octopnml'nez receptors may be locaied in the
Ped.
In the future, one of the most interesting investigations will be to elucidate
wiether 5-HT is a physiological antagonist to NA/OA. Finaly, the study of second
mesenger system such as cyclic adenosine 3'-5' monophosphate (cAMP) synthese
enzyme, adenylate cyclase, which itself appears to influence learning and memory
(Sugawa), and e-qn be actiuted by several biogenic amines, wil most certainly throw
m ore light on the molecular mecbnnism underlying memory.
CONCLUSIONS
From the in-vivo pharmacologcal investigations of learning and memory in
honeybee the following conclusions emerge :
1. Biogenic nmines participate actively in memory formation and in retrieval.
Whether they exert tlzis ftm dion as a neurotransmitter, neuromodulator or neurohormons
remains to be shown:
Dopamine (DA) blocks memory retrieval when injected via the ocelar tract.
Noradrenaline (NA) injected into the alpha-lobes enhances the CR rate in the storage
test but neither in the Peduncl. (Ped) nor in the antermal-lobes. Odopnmine (OA)
also facilitates tlte CR rate in the storage test when injected into the Ped-, but not
into the alpha-lobes. s-Hydroxy-tryptamine (5cHT) induces a reduced CR in both
storage and retrieval experiments when hjecteé into tlte alpha-lobes, however, the
time course in retrieval is very complex. '
2. The mushroom bodies mny be neuronal substrate for the intepation and
pairing of CS-US elements (asociative learning).
3. NA and OA have similar facilitatory adions on mem ory fornution.
5-HT might be a physiologcal antagonist to NA/OA.
Pharmacological studies indicate thnt OM receptors are located in the Ped.
region of mm hroom bodies.