Three-dimensional antennal lobe atlas of male and female moths, Lobesia botrana (Lepidoptera: Tortricidae) and glomerular representation of plant volatiles in females
1 Institut National de la Recherche Agronomique, Unité Mixte de
Recherche en Santé Végétale, Centre de Recherche de
Bordeaux, BP81, 33883 Villenave d'Ornon Cedex, France
2 Institut National de la Recherche Agronomique, Unité de
Phytopharmacie et de Médiateurs Chimiques, Centre de Recherche de
Versailles, 78026 Versailles Cedex, France
3 Department of Chemical Ecology, Swedish Agricultural University, S-230 53
Alnarp, Sweden
* Author for correspondence (e-mail: santon{at}bordeaux.inra.fr)
Accepted 24 January 2005
![]() |
Summary |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Key words: olfaction, tortricid moth, plant volatiles, glomeruli, intracellular recording, anatomical reconstruction, confocal microscopy
![]() |
Introduction |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
The integration of plant odour information in the moth AL has only been
started to be investigated recently. In female Manduca sexta, a
female-specific enlarged glomerulus was found to house arborisations of
projection neurons (PNs) responding to the plant compound linalool only
(King et al., 2000), and more
specifically to one enantiomer of this compound
(Reisenmann et al., 2004
). In
Drosophila melanogaster, electrophysiological characterisation
revealed, conversely, broad tuning and complex responses in second order
neurons (Wilson et al.,
2004
).
To understand better the general organization and the functional
significance of AL glomeruli in odour processing, three-dimensional (3D) AL
maps of a few insect species have been reconstructed
(Rospars, 1983;
Rospars and Chambille, 1989
;
Galizia et al., 1999
;
Laissue et al., 1999
;
Rospars and Hildebrand, 2000
;
Sadek et al., 2002
;
Berg et al., 2002
;
Smid et al., 2003
;
Greiner et al., 2004
).
Comparison of AL atlases from different species enables us to add new
information on general organization principles and to explain specific
adaptation to different biological constraints, such as body size or a
specific odour environment.
The European grapevine moth, Lobesia botrana (Denis and
Schiffmüller), is a major pest of vineyards throughout the world.
Although grapevine is the main host plant, it is a polyphagous insect that can
develop on different species (Bovey,
1966; Stoeva,
1982
). L. botrana has been shown to be attracted by a
non-host plant, tansy (Gabel et al.,
1992
). Gas-chromatography coupled with electroantennograms (EAGs)
revealed that female antennae responded to some tansy volatile compounds, such
as thujyl alcohol,
-thujone and ß-thujone
(Gabel et al., 1992
). Wind
tunnel experiments showed that mated females responded to host plant parts,
but not virgin females and males (I. Masante-Roca, personal observation).
Peripheral EAGs recordings (I. Masante-Roca, personal communication) and AL
intracellular recordings experiments
(Masante-Roca et al., 2002
),
using grapevine compounds as stimuli, revealed that both males and females
respond to most of the tested plant odours
(Masante-Roca et al., 2002
).
Moreover, no significant difference in threshold responses was found between
virgin and mated males or females. However, AL neurons of mated females seemed
to respond more frequently to the tested plant odours than those of mated
males and unmated females (Masante-Roca et
al., 2002
).
In the present study, we established a three-dimensional (3D) atlas of the AL of male and female L. botrana. The map of the female AL serves further as a tool to identify the respective target glomeruli of physiologically characterised PNs, to reveal possible structure-function relationships. The 3D AL atlas will, in the future, also be used to obtain a better understanding of coding mechanisms of grapevine odours as a function of mating and environmental conditions in this pest insect.
![]() |
Materials and methods |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Intracellular recording and stimulation
AL neurons were randomly penetrated by a glass microelectrode with the tip
filled with 4% Lucifer Yellow (LY) CH (Sigma, St Louis, MO, USA) and
backfilled with 2 mol l-1 LiCl. The antenna ipsilateral to the
recording site was ventilated by a steady stream of charcoal-filtered air that
passed through a glass tube at a constant flow of about 20 ml s-1.
The base of the ipsilateral antenna was fixed with wax in an upright position.
Half of the antenna was protruding into the glass tube. When intracellular
contact was established, the antenna was stimulated by pulsing a 5 ml
s-1 airflow during 0.5 s through a Pasteur pipette containing a
clean filter paper, or a filter paper with the solvent or a test compound
inserted into the glass tube 20 cm from the outlet. The bar underneath
the registrations in Fig. 6
indicates the electrical switch of the stimulation device (Stimulus Controler
CS 55, Syntech, Hilversum, The Netherlands). The stimuli were presented in a
random order separated by inter-stimulus-intervals of at least 10 s. For each
neuron, the number of stimuli that could be tested varied depending on the
duration of the recording. If possible, each stimulus was tested more than
once to verify the reproducibility of the responses as described in
Masante-Roca et al.
(2002
).
|
|
Data analysis
The delay, the duration and patterns of excitatory and inhibitory parts of
the responses were analysed manually in detail. Responses were quantified as
described previously (Gadenne and Anton,
2000). Briefly, the net number of spikes (number of spikes during
a 600 ms period after the stimulus minus the number of spikes counted during
the preceding 600 ms representing spontaneous activity) produced in response
to the blank stimulus was subtracted from the net number of spikes produced in
response to an odour stimulus to quantify the response to a specific stimulus.
A neuron was classified as responding to a stimulus when the odour response
exceeded the blank response by at least 10%.
Histology and confocal microscopy
To investigate the neuroanatomical organization of the L. botrana
AL, male and female brains were dissected and fixed in glutaraldehyde, washed
in buffer, dehydrated and embedded in Fluoromount (Sigma). Optical sections
were taken with a confocal microscope (Leica TCS NT; Leica Sollentuna, Sweden)
and analysed on a Silicon Graphics computer work station using Imaris 2.7
Software (Bitplane, Zürich, Switzerland).
To localise the stained individual neurons after physiological recordings,
standard staining methods were used (Anton
and Hansson, 1994). The neurons were stained with 4% LY by passing
0.5 nA of constant hyperpolarizing current through the LY-filled
recording electrode for at least 5 min. After the recording, the brains were
dissected, fixed in a buffered formaldehyde solution, rinsed in buffer, and
examined as whole mounts in Vectashield mounting medium (Vector laboratories,
Burlingame, CA, USA) to be observed in a laser scanning confocal microscope
(Leica TCS SP2, Leica Rueil Malmaison, France), equipped with a krypton/argon
laser. For overview scanning of the whole brain and for the detailed scanning
of each AL, a Leica 20x0.7 dry objective was used. For the overview, the
whole brain was scanned frontally with 2 µm step size whereas the step size
was 1 µm for the detailed scanning of each AL. No additional staining was
used, as auto-fluorescence made the glomerular outlines visible. For the
drawing of the local interneuron (LN), a stack containing the completely
stained neuron was printed out and redrawn manually using transparency paper
as described in Masante-Roca et al.
(2002
).
Three-dimensional reconstruction
The right and left ALs of three different animals were entirely mapped
manually tracing the outline of each individual glomerulus in every optical
section using the Imaris 2.7 software, installed on a Silicon Graphics
computer. The z-axis dimension (thickness of sections) had to be
corrected by a factor 1.6 because of the refractive index mismatch caused by
air objectives. To facilitate usage of the 3D map, each identified glomerulus
was numbered, from the most anterior to the most posterior. In addition,
different colours were given to glomeruli at different anteroposterior levels
(from pink to blue). The dorsal border of the AL, the anterior-ventral cell
body cluster (not drawn to avoid hidden glomeruli), and the antennal nerve
(AN), were used as additional references. The position and shape of all
glomeruli within the complete maps of the three brains were compared on the
computer screen by simultaneously three-dimensionally rotating the different
reconstructions and by comparing sections at different levels throughout the
AL. In addition to the MGC for males, the AN, the cell body cluster, and the
dorsal border of the AL (the tissue forming the dorsal outline of the AL
outside the glomeruli; DB), the three or four most anterior glomeruli and
glomeruli at `strategic' positions were localized in each AL reconstruction
(male and female) and consequently served as landmark glomeruli. As next step,
those glomeruli neighbouring the previously identified landmark glomeruli were
matched. Finally also those glomeruli showing variations in shape, size or
position could be matched due to their neighbouring positions. In the three
investigated brains in males and in females, most glomeruli could be
recognised by following this 3D matching process despite local variations.
To identify glomeruli containing dendritic arborisations of physiologically characterised PNs, ALs were partially reconstructed. These partial reconstructions were compared with the established 3D map using the same matching process as described above. All 3D reconstructions are presented in spatial two-dimensional graphs. The orientation planes are the sagittal plane X (perpendicular to x-axis, X+ as seen from lateral side, X-from medial side), frontal plane Y (perpendicular to y-axis, Y+ as seen from anterior side, Y-from posterior side) and horizontal plane Z (perpendicular to z-axis, Z+ as seen from dorsal side, Z-from ventral side). In addition, sections at the frontal plane were prepared by taking away the upper layers of glomeruli to visualize central glomeruli within the AL. Sketches of the moth brain showing sagittal, frontal and horizontal views, respectively, serve as additional orientation help.
![]() |
Results |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
|
|
|
|
|
In females, the most anterior, pink glomeruli (1-4) are relatively big (around 6000 µm3) and very characteristic in their positions (Figs 2, 3). The next, yellow layer (5-17) is characterised by mostly very small glomeruli (2000 to 3500 µm3) and somewhat bigger landmark glomeruli at a dorsal (5, 7600 µm3), ventral (13, 4700 µm3), and medial (15, 6000 µm3) position. The orange layer (18-27) contains small glomeruli (between 3000 and 5000 µm3) which can be best identified by their relative position between the yellow layer and the red layer (28-43), which itself contains mainly bigger glomeruli (3000 to 7000 µm3) which partially can be easily identified due to their close position to the dorsal border of the AL (31-32) and the AN (35) (Figs 1, 2, 3). Within the green layer (44-59), glomeruli 47 and 56 serve as landmarks with their big size (6000 to 12 000 µm3) and dorsal/ventral position respectively. Most of the glomeruli in the blue layer (61-71) are rather small (around 5000 µm3) and difficult to identify, when comparing different brains. In the two female brains investigated, which had fewer glomeruli than the brain used as a map, `missing' glomeruli belong to the orange, red, green and blue layers (Figs 1, 2, 3).
In males, the most obvious structure in the AL is the potential macroglomerulus (MG) (90 000 µm3) situated at the entrance of the AN (Figs 1, 4, 5). The most anterior, pink layer of ordinary glomeruli consists only of three very small glomeruli (1-3, between 1500 and 3000 µm3). Glomeruli in the yellow layer (4-13) are relatively small and arranged around the first three glomeruli (around 6000 µm3). The orange layer (14-31) is characterised by many small (1500-3000 µm3) and two bigger glomeruli posteromedially of the macroglomerulus (18, 21) (respectively 5000 and 4000 µm3). The red layer (32-42) consists of a circle of glomeruli of different sizes. Glomerulus 38 is situated most ventrally and the neighbouring 37 (14,000 µm3) is bigger than the other glomeruli in the same layer. Glomeruli in the green layer (43-56) are relatively big (between 5000 and 20,000 µm3) and glomeruli 45-49 can be identified by their position close to the AN and posteriorly to the MG. The small glomerulus 55 (5000 µm3) and the big glomerulus 53 (15,000 µm3) are situated most medially. The glomeruli of the blue layer (57-63) form an open circle excluding the lateral side of the AL (Figs 1, 4, 5). The medial glomerulus 63 (14,000 µm3) is bigger than the other glomeruli of that layer.
General physiology of AL neurons
In a total of 15 preparations containing stained neurons with arborisations
in the AL, responses to at least one of the six tested plant odour components
were found. Neuron responses were either excitatory
(Fig. 6A), inhibitory or
combined an initial excitation with a following inhibitory phase. Excitatory
responses in the same neuron had different delays after the onset of
stimulation in some cases (Fig.
6A). Action potential amplitudes ranged from 10 to 40 mV. Nine PNs
and one LN responded to only one of the six tested components, three PNs
responded to two components at the same threshold, one PN responded to
nonatriene at a lower threshold than to ß-thujone and one PN responded to
all six tested components (Table
1). Only the generalist neuron responded to E-2 hexenal, none of
the specialist neurons was found to respond to this component. Most neurons
had a response threshold at 0.1 µg of the applied odours. For hexanol,
-farnesene and ß-thujone, a few neurons had a threshold of 1 µg
and one neuron responded at a threshold of 10 µg to ß-thujone
(Table 1).
Anatomy of physiologically characterised AL neurons
Projection neurons
The cell bodies of the uniglomerular PNs were situated in a large
anterior-ventral cell cluster (see
Masante-Roca et al., 2002).
The primary neurite leads to the innervated glomerulus and fine dendritic
branches were observed throughout the entire glomerulus
(Fig. 6B). The axon was in all
cases only stained within the antennal lobe and therefore, projection areas
within the protocerebrum could not be identified. In two preparations, two PNs
(7a, b; 12 a, b) had been stained simultaneously and in these cases we
identified both target glomeruli (glomeruli 1 and 9; 19 and 8, respectively)
(Table 1).
PN 14 arborised in glomerulus 37 and responded to all tested odours
(Fig. 6B). PNs responding
specifically to a single compound arborised in clearly different glomeruli in
different cases (Fig. 7A,B).
Arborisations in the same, clearly identified glomerulus were found for
neurons that responded to the same component (-farnesene for neurons 1
and 2; ß-thujone for 2 and 3; ß-thujone for 4 and 5), but in all
these cases, at least one of the neurons in each pair responded additionally
to another component (Table 1).
Two PNs responding specifically to different components arborised in the same,
clearly identified glomerulus (Fig.
7C).
|
All glomeruli containing dendritic branches of PNs were situated in the anterior part of the AL. Penetrating with the electrode into posterior layers of the AL resulted in contacts with neurons which did not respond to the tested stimuli. None of the glomeruli in the green and blue layers received branches of a stained PN (Table 1). Only one specifically responding PN (neuron 13) and the generalist PN (neuron 14) arborised in glomeruli of the red layer (Table 1, Figs 6, 8). The vast majority of the stained PNs arborised in glomeruli of the pink and yellow layers (Table 1, Figs 7, 8).
|
Glomerulus 1 is involved in the processing of all tested components except
E2-hexenal (Fig. 8). Glomeruli
containing arborisations from PNs responding to -farnesene occupy a
relatively large S-shaped zone extending from the antero-dorsal to the
posterocentral part of the AL (Fig.
8). Neurons responding to nonatriene arborise in a more
posterolateral group of glomeruli, which does not overlap with the zone
occupied by the dendritic branches of
-farnesene responding PNs
(Fig. 8). Four out of five PNs
responding to ß-thujone have overlapping dendritic arborisations with
-farnesene responding neurons in glomeruli 1 and 3 apart from one
neuron targeting glomerulus 18 (Fig.
8).
Local interneuron
The stained LN arborised in all glomeruli of the AL. The type of
arborisations varied, however, in different glomeruli
(Fig. 9). One glomerulus
contained very dense, fine branches (36), whereas all other glomeruli received
sparse arborisations with bleb-like terminal specialisations. This neuron
responded exclusively to -farnesene.
|
![]() |
Discussion |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
In Lepidoptera, the number of macroglomerular structures is thought to be
correlated with the number of behaviourally active components forming the
pheromone blend in the respective species
(Hansson et al., 1992;
Ochieng' et al., 1995
;
Todd et al., 1995
;
Berg et al., 1998
). In L.
botrana males, we found one large glomerulus close to the entrance of the
antennal nerve. In this species, although one single pheromone component
(E7,Z9-12:Ac) has first been identified as attractant for males
(Roelofs et al., 1973
;
Buser et al., 1974
), a blend
of three compounds has more recently been found to be much more attractive
(El Sayed et al., 1999
).
Therefore, we cannot exclude that other glomeruli are part of a more complex
macroglomerular structure, which could only be identified using a combined
physiological and anatomical approach.
The response characteristics of neurons were similar to those of neurons
studied earlier in L. botrana
(Masante-Roca et al., 2002).
The thresholds of AL neurons for the tested plant compounds are in the same
range or lower as those found earlier in the same species and in other species
for both peripheral receptor neurons and AL neurons
(Anderson et al., 1995
; Anton
and Hansson, 1994
,
1995
;
King et al., 2000
;
Masante-Roca et al., 2002
;
Sadek et al., 2002
;
Greiner et al., 2002
). Larger
specificity of the AL neurons found in the present investigation compared to
an earlier study (Masante-Roca et al.,
2002
) is perhaps partially due to the more limited number of
compounds tested and to the introduction of lower stimulus concentrations.
Conversely, particularly behaviourally active components have been chosen,
which might be represented by more specific neurons compared with more
generally occurring plant compounds. The specificity of the investigated
neurons enables us to test the hypothesis of odour representation in specific
glomeruli at the output level more easily than in a previous studies where
most output neurons had rather broad response spectra
(Sadek et al., 2002
).
A number of methodological problems have to be taken into consideration when interpreting our results. The identification of glomeruli in L. botrana is not unambiguous, because most glomeruli are small, tightly packed and many have a similar size. Glomeruli in the anterior layers of the AL could, however, be much more easily identified than glomeruli in the posterior part of the AL.
The LN with different types of arborisations in different glomeruli might
give a hint on the functional role of this neuron type. Such multiglomerular
LNs with dense arborisations in one single glomerulus and diffuse branching in
the other AL glomeruli were found in different insects. In moths, this type of
neuron has been found very rarely
(Christensen et al., 1993). In
honeybees this neuron type is commonly found
(Fonta et al., 1993
;
Sun et al., 1993
;
Galizia and Kimmerle, 2004
)
and from the detailed analysis of the arborisations, the authors conclude that
the sparse arborisations are output areas (varicosities on branches) and that
the densely innervated single glomerulus comprises input and output regions,
characterised by smooth and varicose branches of the LN. In the beetle,
Pachnoda marginata, LNs with the same features were found
(Larsson, 2001
). The dense and
very fine arborisations in one single glomerulus in L. botrana could
mean that the neuron receives mainly input in this glomerulus. The bleb-like
varicosities on the other branches of the LN, which innervate most if not all
other glomeruli might indicate that these are sites of information output.
This type of LN might therefore be involved in distributing specific
information widely over the AL, e.g. to sharpen a specific signal by lateral
inhibition.
The representation patterns of odour components at the input and output
level of AL glomeruli have only been started to be investigated. In D.
melanogaster, the number of glomeruli is approximately the same as the
number of olfactory receptor molecules and, apart from a few exceptions, each
membrane receptor is expressed in only one or two glomeruli
(Gao et al., 2000;
Vosshall, 2000
;
Bhalerao et al., 2003
).
Olfactory receptor molecules, however, vary widely in their breadth of tuning
(Hallem et al., 2004
). Studies
on a number of moth species (Galizia et
al., 2000
; Carlsson et al.,
2002
; Carlsson and Hansson,
2003
; Meijerink et al.,
2003
; Hansson et al.,
2003
; Skiri et al.,
2004
) and on honeybees
(Joerges et al., 1997
; Galizia
and Menzel, 2000
,
2001
), using optical imaging
techniques, suggest that ORNs responding to a specific plant compound are
represented in one or few identifiable glomeruli. Our data on AL output
neurons in L. botrana support the hypothesis that complex
interglomerular interactions shape the signal emitted by PNs: odours are
represented in an array of PNs arborising in different glomeruli and a single
glomerulus harbours arborisations of PNs responding to different odour
components. In addition, different delays for the responses to different
odours in the same PN indicate that we deal with a highly integrated signal at
that level. Similar structure-function relationships were found in the noctuid
moth, S. littoralis, even though data were not as strong as in the
present study, because most neurons responded to many different compounds
(Sadek et al., 2002
). A recent
electrophysiological study on second order AL neurons in D.
melanogaster revealed also broad tuning and complex responses indicating
lateral interactions between glomeruli within the AL
(Wilson et al., 2004
). These
findings seem to contradict calcium imaging studies performed on the same
species and on honeybees (Wang et al.,
2003
; Sachse and Galizia,
2002
,
2003
), where input and output
patterns matched rather well. These differences can be explained by
methodological problems, as the exact origin of the measured calcium signal is
not yet completely understood (Wilson et
al., 2004
).
A number of recent studies suggest that, in fact, different input-output
relationships might exist in parallel in the AL and what was interpreted as
differences in olfactory processing between different species in the past,
might be dependent mainly on the different experimental approaches and
different subsystems studied. In specific systems like the pheromone system, a
perfect match seems to be present in some species (M. sexta,
Hansson et al., 2003; H.
virescens, Vickers et al.,
1998
), whereas only some overlap between input and output is found
in other species (Trichoplusia ni,
Anton and Hansson, 1999
). In
female M. sexta, a female-specific enlarged glomerulus, possibly
representing also a specialised system, was found to house arborisations of
PNs responding to the plant compound linalool only
(King et al., 2000
), and more
specifically to one enantiomer of this compound
(Reisenmann et al., 2004
). PNs
arborising in adjacent glomeruli responded less specifically to the linalool
enantiomers or a racemic blend (Reisenmann
et al., 2004
).
Of the nine PNs and one LN that responded to only one of the six tested
compounds, six responded to -farnesene. The majority of these PNs
arborised in the anterior central part of the AL.
-farnesene has been
shown to be a potent attractant in the codling moth, Cydia pomonella,
another tortricid moth (Sutherland and
Hutchins, 1972
; Hern and Dorn,
1999
; Bengtsson et al.,
2001
; Coracini et al.,
2004
). Our previous study showed that AL neurons in both males and
females of L. botrana responded to
-farnesene
(Masante-Roca et al., 2002
).
Although this compound is common in many plants, we cannot exclude that it
plays a specific role in host plant attraction in the European grapevine
moth.
In conclusion, by analyzing structure-function relationships in AL output neurons we found specifically responding neurons, which arborised in an array of different glomeruli, indicating complex interglomerular interactions influencing the information leaving the AL. The 3D AL atlas and PN data for mated females will in the future be used to obtain a better understanding of coding mechanisms of grapevine odours in this pest insect as a function of mating and environmental conditions.
![]() |
List of abbreviations |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
![]() |
Acknowledgments |
---|
![]() |
References |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Anderson, P., Hansson, B. S. and Löfqvist, J. (1995). Plant-odour specific receptor neurones on the antennae of female and male Spodoptera littoralis. Physiol. Entomol. 20,189 -198.
Anton, S. and Hansson, B. S. (1994). Central processing of sex pheromone, host odour, and oviposition deterrent information by interneurons in the antennal lobe of female Spodoptera littoralis. J. Comp. Neurol. 350,199 -214.[Medline]
Anton, S. and Hansson, B. S. (1995). Sex pheromone and plant-associated odour processing in antennal lobe interneurons of male Spodoptera littoralis. J. Comp. Physiol. 176,773 -789.
Anton, S. and Hansson, B. S. (1999). Physiological mismatching between neurons innervating olfactory glomeruli in a moth. Proc. R. Soc. Lond. B 266,1813 -1820.[CrossRef]
Anton, S. and Homberg, U. (1999). Antennal lobe structure. In Insect Olfaction (ed. B. S. Hansson), pp. 98-124. Springer.
Bengtsson, M., Bäckman, A. C., Liblikas, L., Ramirez, M. I., Borg-Karlson, A. K., Anderson, P., Löfqvist, J. and Witzgall, P. (2001). Plant odor analysis of apple: antennal response of codling moth females to apple volatiles during phenological development. J. Agric. Food Chem. 49,3736 -3741.[CrossRef][Medline]
Berg, B. G., Almaas, T. J., Bjaalie, J. G. and Mustaparta, H. (1998). The macroglomerular complex of the antennal lobe in the tobacco budworm moth Heliothis virescens: specified subdivision in four compartments according to information about biologically significant compounds. J. Comp. Physiol. 183,669 -682.[CrossRef]
Berg, B. G., Galizia, C. G., Brandt, R. and Mustaparta, H. (2002). Digital atlases of the antennal lobe in two species of tobacco budworm moths, the oriental Helicoverpa assulta (male) and the american Heliothis virescens (male and female). J. Comp. Neurol. 446,123 -134.[CrossRef][Medline]
Bhalerao, S. S. A., Stocker, R. F. and Rodrigues, V. (2003). Olfactory neurons expressing identified receptor genes project to subsets of glomeruli within the antennal lobe of Drosophila melanogaster. J. Neurobiol. 54,577 -592.[CrossRef][Medline]
Boeckh, J. and Tolbert, L. P. (1993). Synaptic organization and development of the antennal lobe in insects. Microsc. Res. Techn. 24,260 -280.[Medline]
Bovey, P. (1966). Super famille des Tortricidae. In Entomologie Appliquée à l'Agriculture (ed. A. S. Balachovsky), pp.456 -893. Paris: Masson.
Buser, H. R., Rauscher, S. and Arn, H. (1974). Sex pheromone of Lobesia botrana: (E,Z)-7,9-dodecadienyl acetate in the female grape vine moth. Z. Naturforsch. 29,781 -783.
Carlsson, M. A. and Hansson, B. S. (2003).
Dose-response characteristics of glomerular activity in the moth antennal
lobe. Chem. Senses 28,269
-278.
Carlsson, M. A., Galizia, C. G. and Hansson, B. S.
(2002). Spatial representation of odours in the antennal lobe of
the moth Spodoptera littoralis (Lepidoptera:Noctuidae).
Chem. Senses 27,231
-244.
Christensen, T. A. and Hildebrand, J. G. (1987). Male-specific, sex pheromone-selective projection neurons in the antennal lobes of the moth, Manduca sexta. J. Comp. Physiol. 160,553 -569.[CrossRef]
Christensen, T. A., Waldrop, B. R., Harrow, I. D. and Hildebrand, J. G. (1993). Local interneurons and information processing in the olfactory glomeruli of the moth Manduca sexta. J. Comp. Physiol. 173,385 -399.
Coracini, M., Bengtsson, M., Liblikas, I. and Witzgall, P. (2004). Attraction of codling moth males to apple volatiles. Entomol. Exp. Appl. 110,1 -10.[CrossRef]
El-Sayed, A., Gödde, J., Witzgall, P. and Arn, H. (1999). Characterization of pheromone blend for grapevine moth, Lobesia botrana by using flight track recording. J. Chem. Ecol. 25,389 -400.[CrossRef]
Fiala, A., Spall, T., Diegelmann, S., Eisermann, B., Sachse, S., Devaud, J.-M., Buchner, E. and Galizia, C. G. (2002). Genetically expressed cameleon in Drosophila melanogaster is used to visualize olfactory information in projection neurons. Curr. Biol. 12,1877 -1884.[CrossRef][Medline]
Fonta, C., Sun, X. J. and Masson, C. (1993). Morphology and spatial distribution of bee antennal lobe interneurons responsive to odours. Chem. Senses 18,101 -119.
Gabel, B., Thiéry, D., Suchy, V., Marion-Poll, F., Hradsky, P. and Farkas, P. (1992). Floral volatiles of Tanacetum vulgare L. attractive to Lobesia botrana Den. and Schiff. females. J. Chem. Ecol. 18,693 -701.[CrossRef]
Gadenne, C. and Anton, S. (2000). Central processing of sex pheromone stimuli is differentially regulated by juvenile hormone in a moth. J. Insect Physiol. 46,1195 -1206.[CrossRef][Medline]
Galizia, C. G. and Kimmerle, B. (2004). Physiological and morphological characterization of honeybee olfactory neurons combining electrophysiology, calcium imaging and confocal microscopy. J. Comp. Physiol. A 190,21 -38.
Galizia, C. G. and Menzel, R. (2000). Odour perception in honeybees: coding information in glomerular patterns. Curr. Opin. Neurobiol. 10,504 -510.[CrossRef][Medline]
Galizia, C. G. and Menzel, R. (2001). The role of glomeruli in the neural representation of odours: results from optical recording studies. J. Insect Physiol. 47,115 -130.[CrossRef][Medline]
Galizia, C. G., Mellwrath, S. L. and Menzel, R. (1999). A digital three-dimensional atlas of the honeybee antennal lobe based on optical sections acquired by confocal microscopy. Cell Tissue Res. 295,383 -394.[CrossRef][Medline]
Galizia, C. G., Sachse, S. and Mustaparta, H. (2000). Calcium responses to pheromones and plant odours in the antennal lobe of the male and female moth Heliothis virescens. J. Comp. Physiol. A 186,1049 -1063.[Medline]
Gao, Q., Yuan, B. and Chess, A. (2000). Convergent projections of Drosophila olfactory neurons to specific glomeruli in the antennal lobe. Nature Neurosci. 3, 780-785.[CrossRef][Medline]
Greiner, B., Gadenne, C. and Anton, S. (2002).
Central processing of plant volatiles in Agrotis ipsilon males is
age-independent in contrast to sex pheromone processing. Chem.
Senses 27,45
-48.
Greiner, B., Gadenne, C. and Anton, S. (2004). Three-dimensional antennal lobe atlas of the male moth, Agrotis ipsilon: a tool to study structure-function correlation. J. Comp. Neurol. 475,205 -210.
Hallem, E. A., Fox, A. N., Zwiebel, L. J. and Carlson, J. R. (2004). Mosquito receptor for human-sweat odorant. Nature 427,212 -213.[CrossRef][Medline]
Hansson, B. S. and Christensen, T. A. (1999). Functional characteristics of the antennal lobe. In Insect Olfaction (ed. B. Hansson), pp. 126-164. Springer.
Hansson, B. S., Ljungberg, H., Hallberg, E. and Löfstedt, C. (1992). Functional specialization of olfactory glomeruli in a moth. Science 256,1313 -1315.[Medline]
Hansson, B. S., Carlsson, M. A. and Kalinova, B. (2003). Olfactory activation patterns in the antennal lobe of the sphinx moth, Manduca sexta. J. Comp. Physiol. A 189,301 -308.
Hern, A. and Dorn, S. (1999). Sexual dimorphism
in the olfactory orientation of adult Cydia pomonella in response to
-farnesene. Entomol. Exp. Appl.
92, 63-72.
Joerges, J., Küttner, A., Galizia, C. G. and Menzel, R. (1997). Representations of odours and odour mixtures visualized in the honeybee brain. Nature 387,285 -288.[CrossRef]
Kanzaki, R., Arbas, E. A., Strausfeld, N. J. and Hildebrand, J. G. (1989). Physiology and morphology of projection neurons in the antennal lobe of the male moth Manduca sexta. J. Comp. Physiol. 165,427 -453.[CrossRef]
King, J. R., Christensen, T. A. and Hildebrand, J. G.
(2000). Response characteristics of an identified, sexually
dimorphic olfactory glomerulus. J. Neurosci.
20,2391
-2399.
Laissue, P. P., Reiter, C., Hiesinger, P. R., Halter, S., Fischbach, K. F. and Stocker, R. F. (1999). Three-dimensional reconstruction of the antennal lobe in Drosophila melanogaster. J. Comp. Neurol. 405,543 -552.[CrossRef][Medline]
Larsson, M. (2001). Neural interfaces to the odour world of scarab beetles. PhD thesis, Department of Ecology, Lund University, Sweden.
Masante-Roca, I., Gadenne, C. and Anton, S. (2002). Plant odour processing in the antennal lobe of male and female grapevine moths, Lobesia botrana (Lepidoptera: Tortricidae). J. Insect Physiol. 48,1111 -1121.[CrossRef][Medline]
Meijerink, J., Carlsson, M. A. and Hansson, B. S. (2003). Spatial representation of odorant structure in the moth antennal lobe: a study of structure response relationships at low doses. J. Comp. Neurol. 467,11 -21.[CrossRef][Medline]
Mustaparta, H. (1996). Central mechanisms of pheromone information processing. Chem. Senses 21,269 -275.[Abstract]
Ochieng', S. A., Anderson, P. and Hansson, B. S. (1995). Antennal lobe projection patterns of olfactory receptor neurons involved in sex pheromone detection in Spodoptera littoralis (Lepidoptera: Noctuidae). Tissue Cell 27,221 -232.[Medline]
Reisenmann, C. E., Christensen, T. A., Francke, W. and
Hildebrand, J. G. (2004). Enantioselectivity of projection
neurons innervating identified olfactory glomeruli. J.
Neurosci. 24,2602
-2611.
Roelofs, W. L., Kochansky, J., Cardé, R. T., Arn, H. and Rauscher, S. (1973). Sex attractant of the grape vine moth, Lobesia botrana. Mitt. Schweiz. Entomol. Ges. 46, 71-73.
Rospars, J. P. (1983). Invariance and sex-specific variations of the glomerular organization in the antennal lobe of a moth, Mamestra brassicae and a butterfly, Pieris brassicae. J. Comp. Neurol. 220, 80-96.[Medline]
Rospars, J. P. (1988). Structure and development of the insect antennodeutocerebral system. Int. J. Insect Morphol. Embryol. 17,243 -294.[CrossRef]
Rospars, J. P. and Chambille, I. (1989). Identified glomeruli in the antennal lobes of insects: invariance, sexual variation and postembryonic development. In Neurobiology of Sensory Systems (ed. R. N. Singh and N. J. Strausfeld), pp.355 -375. New York: Plenum Press.
Rospars, J. P. and Hildebrand, J. G. (1992). Anatomical identification of glomeruli in the antennal lobe of the male sphinx moth, Manduca sexta. Cell Tissue Res. 270,205 -227.[Medline]
Rospars, J. P. and Hildebrand, J. G. (2000).
Sexually dimorphic and isomorphic glomeruli in the antennal lobe of the sphinx
moth Manduca sexta. Chem. Senses
25,119
-129.
Sachse, S. and Galizia, C. G. (2002). Role of
inhibition for temporal and spatial odor representation in olfactory output
neurons: a calcium imaging study. J. Neurophysiol.
87,1106
-1117.
Sachse, S. and Galizia, C. G. (2003). The coding of odour-intensity on the honeybee antennal lobe: local computation optimizes odour representation. Eur. J. Neurosci. 18,2119 -2132.[CrossRef][Medline]
Sadek, M. M., Hansson, B. S., Rospars, J. P. and Anton, S.
(2002). Glomerular representation of plant volatiles and sex
pheromone components in the antennal lobe of the female Spodoptera
littoralis. J. Exp. Biol.
205,1363
-1376.
Schreier, P., Drawert, F. and Junker, A. (1976). Identification of volatile constituents from grapes. J. Agric. Food Chem. 24,331 -336.
Skiri, H., Galizia, C. G. and Mustaparta, H.
(2004). Representation of primary plant odorants in the antennal
lobe of the moth Heliothis virescens using calcium imaging.
Chem. Senses 29,253
-267.
Smid, H. M., Bleeker, M. A. K., van Loon, J. J. A. and Vet, L. E. M. (2003). Three-dimensional organization of the glomeruli in the antennal lobe of the parasitoid wasps Cotesia glomerulata and C. rubecula. Cell Tissue Res. 312,237 -248.[Medline]
Stockel, J., Roehrich, R., Carles, J. P. and Nadaud, A. (1989). Techniques d'élevage pour l'obtention programmée d'adultes vierges d'Eudémis. Phytoma 412,45 -47.
Stoeva, R. (1982). Les hôtes de l'Eudémis (Lobesia botrana Schiff.) en Bulgarie. Hort. Viticult. Science 19, 83-89.
Sun, X. J., Tolbert, L. P. and Hildebrand, J. G. (1993). Ramification pattern and ultrastructural characteristics of the serotonin-immunoreactive neuron in the antennal lobe of the moth Manduca sexta: a laser scanning confocal and electron microscopy study. J. Comp. Neurol. 338, 5-16.[Medline]
Sutherland, O. R. W. and Hutchins, R. F. N.
(1972). -farnesene, a natural attractant for codling moth
larvae. Nature 239,170
.
Todd, J. L., Anton, S., Hansson, B. and Baker, T. C. (1995). Functional organization of the macroglomerular complex related to behaviorally expressed olfactory redundancy in male cabbage looper moth. Physiol. Entomol. 20,349 -361.
Vickers, N. J., Christensen, T. A. and Hildebrand, J. G. (1998). Combinatorial odor discrimination in the brain: attractive and antagonist odor blends are represented in distinct combinations of uniquely identifiable glomeruli. J. Comp. Neurol. 400, 35-56.[CrossRef][Medline]
Vosshall, L. B. (2000). Olfaction in Drosophila. Curr. Opin. Neurobiol. 10,498 -503.[CrossRef][Medline]
Wang, J. W., Wong, A. M., Flores, J., Vosshall, L. B. and Axel, R. (2003). Two-photon calcium imaging reveals an odor-evoked map of activity in the fly brain. Cell 112,271 -282.[Medline]
Wilson, R. I., Turner, G. C. and Laurent, G.
(2004). Transformation of olfactory representations in the
Drosophila antennal lobe. Science
303,366
-370.
Related articles in JEB: