j *@ - Sociedade Brasileira de Psicologia

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nervous system of the bee can be divided into the cerebral ganglion wit pro o-,
and tritocerebrum, the suboesophageal ganglion (SOG), which is fused to the cerebral
ganglion, and the ventral nerve chord . The protocerebrum contains the optic lobes,
ocelar tract neuropile, m ushroom bodies and central complex. The deutocerebrum is
composed of the antennal and dorsal lobes, while the tritocerebrum is a diffuse neuropilar
area between the deutocerebrum and SOG.
The brain of the bee contains two major sensory input regions: the two
compotmd eyes and the antennae. Visual information coming in from one compound
eye is processed in three visual ganglia: lamina, medula and lobula and further
conveyed to the median protocerebrdlm and the contralateral optic lobe. The antennal
and dorsal lobes are the first relay stations for olfactory and mechanosensory information
from the antennae (Pareto, 1972). The glomeruli of the antennal lobes are the
sites of synaptic interactions between olfactory receptor cels, local interneurons and
output relay neurons. The output neurons are organized in three separate tracts which
project into the mtkshroom bodies: the lateral, mediolateral and medial antennoglomerularis
tract (l.a.g.t., m.l.a.g.t., m.a.g.t.). The dorsal lobes give rise to antennal motorneurons
and some descending neurons (Suzuki, 1975).
The mushroom bodies are thought to be a complex integration center, where
sensory input from the optic lobes (via the anterior superior optic tract, a.s.o.t.) ànd
the antennal lobes (via the a.g.t.s.) converges. Their neuropil can be subdivided into a
median and a lateral calyx, a pedtmculus, and an alpha- and a beta-lobe. The calyces
are the sites of synaptic contacts between the sensory projection neurons and the
mushroom body intrinsic elements caled Kenyon cels. Their projection fibers run
into the peduncullzs and bifurcate at its base to send one process into the beta-lobe
and the other into the alpha-lobe, preserving their positional information in a paralel,
map-like organizition, analogue to the mammalian cerebelum (Kenyony 1896). The
alpha-and beta-lobes are thought to be the output regions of the mushroom bodies
(Mobbs, 1982, 1984). There, many Kenyon cels converge onto few extrinsic neurons,
which arborize in the diffuse protocerebrum surrounding these output regions. So far,
little is known about the precise connectivity of the extrinsic eiements to other brain
structures, for e= mple the SOG.
'Ihe SOG is formed by the embryonic fusion of three neuromeres, the
mandibular, the maxillary and labial nelzromeres. It receives sensory information from
the nerves of the mouthparts and the antennae, and gives rise to motoneurons which
supply the muscles of the mouthparts (Rehder, 1987). 'rhlzs it can be considered as
the sensory and motor center for feeding. Ip addition, it serves as a relay station for
descending interneurons from the brain into the ventral nerve chord.