Distribution of metabotropic receptors of serotonin, dopamine, GABA, glutamate, and short neuropeptide F in the central complex of Drosophila.

The central complex is a prominent set of midline neuropils in the insect brain, known to be a higher locomotor control center that integrates visual inputs and modulates motor outputs. It is composed of four major neuropil structures, the ellipsoid body (EB), fan-shaped body (FB), noduli (NO), and protocerebral bridge (PB). In Drosophila different types of central complex neurons have been shown to express multiple neuropeptides and neurotransmitters; however, the distribution of corresponding receptors is not known. Here, we have mapped metabotropic, G-protein-coupled receptors (GPCRs) of several neurotransmitters to neurons of the central complex. By combining immunocytochemistry with GAL4 driven green fluorescent protein, we examined the distribution patterns of six different GPCRs: two serotonin receptor subtypes (5-HT(1B) and 5-HT(7)), a dopamine receptor (DopR), the metabotropic GABA(B) receptor (GABA(B)R), the metabotropic glutamate receptor (DmGluR(A)) and a short neuropeptide F receptor (sNPFR1). Five of the six GPCRs were mapped to different neurons in the EB (sNPFR1 was not seen). Different layers of the FB express DopR, GABA(B)R, DmGluR(A,) and sNPFR1, whereas only GABA(B)R and DmGluR(A) were localized to the PB. Finally, strong expression of DopR and DmGluR(A) was detected in the NO. In most cases the distribution patterns of the GPCRs matched the expression of markers for their respective ligands. In some nonmatching regions it is likely that other types of dopamine and serotonin receptors or ionotropic GABA and glutamate receptors are expressed. Our data suggest that chemical signaling and signal modulation are diverse and highly complex in the different compartments and circuits of the Drosophila central complex. The information provided here, on receptor distribution, will be very useful for future analysis of functional circuits in the central complex, based on targeted interference with receptor expression.

Olfactory activation patterns in the antennal lobe of the sphinx moth, Manduca sexta.

The sphinx moth Manduca sexta is a well-studied insect with regard to central olfactory functions. Until now, the innervation patterns of olfactory receptor neurons into the array of olfactory glomeruli in the antennal lobe have, however, been unclear. Using optical imaging to visualize calcium dynamics within the antennal lobe we demonstrate specific patterns elicited by sex pheromone components and plant-derived odours. These patterns mainly reflect receptor neuron activity. Within the male-specific macroglomerular complex the two major pheromone components evoke stereotyped activity in either of two macroglomerular complex glomeruli. Based on previous knowledge of output neuron specificity, our results suggest a matching of information between input and output in the macroglomerular complex. Plant odours evoked activity in the sexually isomorphic glomeruli. Two major results were obtained: (1). terpenes and aromatic compounds activate different clusters of glomeruli with only minor overlapping, and (2). the position of certain key glomeruli is fixed in both males and females, which suggests that host-plant related odorants are processed in a similar way in both sexes.

Circulating gonadotrophins and follicular dynamics in anestrous ewes after treatment with estradiol-17beta.

Plasma FSH, LH, estradiol (E2) and progesterone (P4) profiles and patterns of follicular growth and regression by ultrasonography were determined after E2 treatment (1 microg/kg) in anestrous ewes. Fifteen ewes were treated with one (group I, n=7) or two (group II, n=4) i.m. injections of E2 with a 24h interval, or two oil injections with a 24h interval (group C, n=4). Blood samples for E2, P4, FSH and LH determinations were collected daily 4 days before the initiation of the treatment (day 0), when bleeding increased to every 2h starting 2h before treatment until 56h after the first injection and from then on every 6h until day 8, and twice per day till the end of the experiment (day 9). During the experimental period (days -4 to 9), transrectal ultrasonic examinations were carried out daily using a 7.5 MHz linear array probe. Number and size of follicles > or =3mm in diameter were recorded. No estrous was detected before, during or after treatment. LH and FSH surges were observed 10-18h after the first E2 injection. The second E2 injection stimulated another release of LH but no surges. E2 inhibited FSH levels before the surge and the second E2 injection induced a longer inhibition. No ovulation was detected by ultrasonography during the experimental period and P4 levels remained low (<0.7 nmol/l) before, during and after the treatment in all ewes. There was an effect of E2 treatment on the diameter of the largest follicle, a decrease could be observed 3 days after the first injection in both ewes of groups I and II. The E2-treated groups had a higher frequency of ewes showing wave emergence on day 3 (day 1.5+/-1,2.4+/-0.4 and 2.5+/-0.5 for control, groups I and II). LH and FSH surges were observed after E2 treatment, but were not able to provoke ovulation neither luteinization. In contrast, the treatment was associated with the regression of the largest follicle and with emergence of a new follicular wave on day 3.

Intimal hyperplasia recurs after removal of PDGF-AB and -BB inhibition in the rat carotid artery injury model.

Several antagonists specific for platelet-derived growth factor (PDGF) or its receptors have recently been developed and shown to inhibit intimal hyperplasia formation in various animal models, but data investigating the durability of this intervention is limited. The present study was designed to investigate the potency of PDGF B-chain aptamer, a novel type of PDGF-AB and -BB antagonist, in the rat carotid model and to characterize intermediate-term effects on lesion formation. One hundred thirty-four animals were randomized to aptamer treatment or placebo. Daily treatment with the antagonist resulted in a 50% reduction in lesion size at 2 weeks (P<0.001). The beneficial effect involved increased apoptosis and possibly an interference with smooth muscle cell migration. Discontinuing administration 1 week earlier did not give any significant benefit compared with phosphate-buffered saline-treated controls. When the antagonist was administered for 2 weeks and the vessels analyzed 6 weeks later, the beneficial effect was lost and the treated lesions had a higher intima-media and area-cell ratio compared with the treated lesions in the 2-week-endpoint study. Our findings confirm a role of PDGF B-chain in intimal hyperplasia, but the successful use of PDGF antagonists may require either prolonged treatment or combination therapy with other agents.

Progesterone and oestradiol in canine plasma monitored by enhanced luminescence immunoassays.

The Amerlite immunoassay system was evaluated for direct measurement of progesterone and oestradiol in canine plasma. The progesterone assay was evaluated without modification. To increase the sensitivity of the oestradiol assay, the horseradish peroxidase-labelled tracer was diluted 1:2 and the antiserum 1:10. Subsequently, the standards supplied in the kit were altered to produce a new standard curve. The dilution curves of canine plasma samples with high progesterone and oestradiol contents were parallel with the standard curves based on human serum. The relation between measurements of both hormones in canine plasma using established extraction methods as references and the Amerlite procedures were highly comparable, resulting in the linear regression equations y = 0.91x + 1.3 (progesterone, n = 100) and y = 0.79x + 0.9 (oestradiol, n = 84). However, for oestradiol the closest relation to the reference method was achieved when the incubation period was extended to 24 h at 4 degrees C. When measuring oestradiol and progesterone in canine sera during the oestrous cycle the hormone patterns were not influenced by the methods applied.

Radioimmunoassay of bovine, ovine and porcine luteinizing hormone with a monoclonal antibody and a human tracer.

A radioimmunoassay for bovine (bLH), ovine (oLH) and porcine (pLH) luteinizing hormone was developed using a human 125ILH tracer from a commercial kit and a monoclonal antibody (518B7) specific for LH but with low species specificity. Standard curves demonstrated similar binding kinetics when bLH, oLH and pLH were incubated with tracer and antibody for 2 h at room temperature. A 30-min delay in the addition of the tracer gave sufficient sensitivity when analysing pLH. Separation of antibody-bound LH from free hormone was achieved by using second antibody-coated micro Sepharose beads. The assay was validated and the performance compared with that of an RIA currently in use for determination of bLH and oLH (coefficient of correlation: 0.99 and 0.98). Regardless of the standards used, intra-assay coefficients of variation were < 10% for LH concentrations exceeding 1 microgram/L. The inter-assay coefficients of variation were < 15%. The assay was used for clinical evaluation demonstrating the pre-ovulatory LH surge in two cyclic cows, LH pulsatility in an oophorectomized ewe and LH response to GnRH injection in a boar.