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Sensilla on the antennal funiculus of the blow fly, Protophormia terraenovae (Diptera: Calliphoridae)
No full textThe morphology of the antennal funiculus and the external morphological characteristics and distribution
of sensilla of blow fly, Protophormia terraenovae, have been studied using light and scanning
electron microscopy. Cross section of the funiculus is roughly triangular in shape, with an anterior-medial,
anterior-lateral, and posterior surface. The latter presents some large-size pits on restricted lateral and
median areas of the proximal funiculus, and several smaller-size ones close to the pedicel–funiculus
joint. The entire surface of the antennal sub-segment appears densely populated by microtrichia and is
inhabited by seven types of sensilla: one trichoid, two basiconic, one auriculate, one coeloconic, and two
basiconic-like pit sensilla. Trichoid, basiconic, auriculate and basiconic-like types display a multiporous
wall, a feature characteristic of insect olfactory sensilla. It remains to be verified whether or not the coeloconic
structure type has wall pores. The most abundant sensilla are the trichoid ones, which are followed
by the basiconic, coeloconic and auriculate types in a decreasing density order. The basiconic-like pit sensilla
are present only on the posterior funicular surface, unlike the remaining ones which populate the
entire sub-segment. The blow fly’ funiculus displays a significant, even though moderate sexual dimorphism,
the female sub-segment being bigger and presenting a higher number of trichoid and auriculate
sensilla. The presence of multiple wall pores in most of sensilla types implies an olfactory modality
for sensory neurons they accomodate, thus indicating that the blow fly’ funiculus is a plain olfactory
organ
Drosophila Parkinson's mutant display olfactory impairment both to natural and synthetic compounds
No full textImpairment of the bradycardia response to apnoea and simulated diving in smokers
No full textApnoea and diving induce autonomic cardiovascular responses of bradycardia and blood flow
redistribution toward vital organs that are aimed at improving subject survival in hypoxic
conditions. Among factors that influence autonomic nervous activity, and thus affect
cardiovascular responses, cigarette smoking is known to reduce vagal cardiac-nerve activity
and to increase sympathetic nervous activity. In this study we have assessed the bradycardia
response to apnoea and to diving in human smokers. By recording electrocardiograms, heart
rate (HR) was monitored on ten healthy habitual smokers (SM) and ten non-smokers (non-SM),
in eupnoea, in air, and in simulated diving (facial immersion in water, 22 °C). The latter two
conditions included apnoea and snorkelling sessions lasting 30 s each. Apnoea in air induced a
3% and a 4% HR reduction in SM and non-SM, respectively. Only in the latter, however,
instantaneous HR decreased throughout the session, thus showing the occurrence of a weaker
response in SM. During apnoea in simulated diving, a delayed and lower-amplitude bradycardia
occurred in SM compared to non-SM, HR decreasing by 13% and 22%, respectively.
Analogously, the cardiac response to snorkelling in simulated diving was smaller in SM with
respect to non-SM, HR decreasing by 7% and 14%, respectively. These response patterns
suggest that cardiac homeostatic adjustments to apnoea and diving are impaired in smokers.
Besides causing a number of pathologies, cigarette smoking represents a risk factor for subjects
performing these activities at an even non-competitive level
Palpal receptors of the olive fly bactrocera oleae play a key role in foraging behaviorand host finding.
No full textThe olive fly Bactrocera oleae (Rossi) is a serious pest of
olives in several countries in the Mediterranean basin causing
important losses in the oil industry. The olive fly is known to
respond behaviorally to volatile compounds present in its habitat and, more specifically, to those released from its host plant
that play an important role in guiding the oviposition behavior
of gravid females. A recent research by Liscia et al. (2013) on
a laboratory strain of B. oleae demonstrated that that volatiles
released from a bacterial filtrate (obtained culturing
Pseudomonas putida) are mainly detected by palpal olfactory
receptors rather than the antennal sensilla. On the contrary, α-
pinene, a key compound in triggering the oviposition (Scarpati
et al., 1993) that is emitted by leaves and half–ripe olives is
mainly detected by male insects with the antennal receptors. On
these bases, this study has been aimed to further investigate the
role of maxillary palps in detecting food and oviposition sites in
wild B. oleae adults obtained from pupae collected in different
areas of olive orchards in Sardinia. Electrophysiological (EAG
and EpG) and behavioral bioassays (Y-tube olfactometer and
wind tunnel) were performed to test bacterial filtrate volatiles
and some host plant (α-pinene) and food sources (acetic acid)
related compounds. Dose-response relationships and differences
in sensitivity related to insect sex and physiological condition
were identified. Responses were compared to those obtained in
lab insects. The results obtained in wild insects confirmed that
palpi have a higher sensitivity to bacterial filtrate than the
antennae. Otherwise, the EpG recorded in mated females in
response to α-pinene and acetic acid, showed a lower threshold
and a greater signal amplitude than those recorded in lab
insects both in the palpi and the antennae. Electrophysiological
results are complementary with the behavioral ones. In conclusion, the maxillary palp olfactory receptors play a primary role
in the short-range detection of chemicals cues from host plant
and epiphytic bacteria. These findings open new perspectives for
improving olive fly control strategies
Characterization of olfactory sensilla of the olive fly: Behavioral and electrophysiological response to volatile organic compounds from the host plant and bacterial filtrate
No full textThe responses of olive fly (Bactrocera oleae) antennal and palpal olfactory receptors to odors emitted by
Pseudomonas putida bacterial filtrate and to volatiles from a host plant were evaluated using electrophysiological
and behavioral bioassays. Morphological identification of olfactory receptors was also performed.
The third antennal segment (flagellum) bears four types of multiporous sensilla: trichoid,
short basiconica, clavate and grooved. Maxillary palps have mechanosensory bristles and multiporous
basiconica sensilla. In wind-tunnel bioassays, olive fly responses to volatiles emitted by bacterial filtrate
were higher than those to culture medium. Bacterial filtrate was more attractive than ammonium carbonate
or a mixture of ethyl acetate and acetic acid in ethanol. GC–MS of bacterial filtrate identified some
of the chemicals produced by bacterial activity, including methyl thiolacetate, ammonia, 2-pentanone, 2-
heptanone, ethyl tiglate and methyl thiocyanate. Electrophysiological investigations proved that antennal
sensilla are responsive to bacterial filtrate odor, methyl thiolacetate, olive leaves and olives, as well as to
a-pinene, while acetic acid elicited an inhibitory response. Electropalpgrams recorded a specific response
to bacterial filtrate by mated males and females, as well as a dose-dependent response relationship to
methyl thiolacetate by mated females. The identification of new active volatile compounds in the semiochemical
system of the olive fly is promising for the development of innovative control strategies in areawide
management
OLFACTORY DYSFUNCTION AS POTENTIAL BIOMARKER IN NEURODEGENERATIVE DISORDERS
No full textObjectives: olfactory dysfunctions increase with age, 2% of the population under 65 years and 75% over 80 years had olfactory deficits. The main causes of olfactory dysfunctions are viral infections, head trauma and neurodegenerative disorders. Aim of this study is to update current knowledge about the relationship between olfactory dysfunction and neurodegenerative disorders such as Parkinson’s disease (PD)(1), Alzheimer’s disease (AD)(2), progressive supranuclear palsy (PSP), essential tremor (ET) and Huntington’s disease (HD)(3).
Methodology: olfactory function is usually evaluated through different approaches, such as psychophysical, electrophysiological and neuroimaging techniques. The main components of olfactory function are odor threshold (OT), identification (OI) and discrimination (OD).
Results: According to literature, patients with PD and AD show severe olfactory dysfunction, nevertheless OT is more impaired in PD than in AD, while OI seems more impaired in AD than in PD. OI are normal in ET and PSP, the latter showing also normal OT, both have poor OD. HD show significant deficits only in OI. Interestingly, olfactory dysfunctions often precede motor symptoms of parkinsonism and are investigated as a potential biomarker in subjects at risk (4).
Conclusion: olfactory function could help in early detection and differential diagnosis of neurodegenerative disorders
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Drosophila Shaker Mutants as Model of Bipolar Disorder: Effects of Memantine on Activity and Sleep Patterns
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