Molecular cloning, mRNA expression and biological activity of the pheromone biosynthesis activating neuropeptide (PBAN) from the European corn borer, Ostrinia nubilalis.

Pheromone biosynthesis activating neuropeptide (PBAN) is a member of the pyrokinin (FXPRLamide) insect neuropeptides. Here, we report the cloning of the gene Ostnu-PBAN from the E and Z pheromone strains of the European corn borer (ECB), Ostrinia nubilalis (Lepidoptera: Crambidae), a major pest of maize. The Ostnu-PBAN genomic sequence is > 5 kb in length and consists of six exons. The deduced amino acid sequence revealed a 200-residue precursor protein including a signal peptide, a 24-amino acid (aa) diapause hormone, a 37-aa PBAN and three other FXPRLamide neuropeptides. Our in vivo assays suggest that the 37-aa synthetic Ostnu-PBAN is hormonally active in the pheromone gland. It restores sex pheromone production to normal levels in mated females and decapitated virgins of both E and Z cultures. The results of a real-time PCR analysis indicated that Ostnu-PBAN mRNA levels reached a plateau in the brain-suboesophageal ganglion complexes 1 day after eclosion, and mating did not affect the mRNA expression. Three size classes of Ostnu-PBAN mRNA (1.9, 2.0 and 2.1 kb) were obtained, differing only in the length of the 3' untranslated region. However, there was no correlation between sequence divergence and the pheromone composition, voltinism or geographical origin (Hungary, Slovenia, Sweden, Turkey) of ECB moths.

Plasma nociceptin levels are reduced in migraine without aura.

It was demonstrated that both nociceptin, a novel opioid neuropeptide, and its receptor are present in trigeminovascular neurons. In an animal model nociceptin dose-dependently inhibited neurogenic dural vasodilatation. These results suggest that nociceptin may be involved in neurovascular headaches such as migraine. To test this hypothesis, we studied circulating nociceptin levels in 18 patients suffering from migraine without aura and in 24 controls. Headache-free migraineurs had significantly lower nociceptin levels than controls (5.79 +/- 1.82 vs. 9.74 +/- 2.43 pg/ml, P < 0.0001, Student's t-tests). Nociceptin levels were further reduced in six patients studied in the first 3 h of typical migraine attacks (1.04 +/- 0.17 pg/ml). Nociceptin levels correlated with the frequency of attacks in this group of migraineurs. Lower interictal nociceptin levels may contribute to a defective regulation of trigeminovascular neurons in migraineurs which might be important in the pain process of migraine.

Cluster headache patients show marked intensity dependence of cortical auditory evoked potentials during and outside the bout.

Central serotonergic neurotransmission was assessed using intensity dependence of cortical auditory evoked potentials (IDAP) in cluster headache (CH) patients during both the active and interictal period. In 15 episodic CH patients and 13 controls previously described methods were used and amplitude-stimulus intensity function (ASF) slopes were computed. In the cluster group mean ASF slope was significantly steeper than in the control group both during the active period (1.53+/-0.90 vs. 0.77+/-0.85, P=0031) and interictally (1.85+/-1.20 vs. 0.77+/-0.85, P=0012). In the cluster group IDAPs of active and interictal period did not differ significantly (P=0378). Duration of the disease or the present bout, distance from the last attack did not correlate with ASF slopes. In conclusion, our results are compatible with decreased level of serotonergic neurotransmission in raphe-cortical pathways. Diminished serotonergic activity in raphe-hypothalamic serotonergic pathways might be hypothesized influencing the activity of hypothalamic neurons and thus play a role in the genesis of cluster headache.

Circulating nociceptin levels during the cluster headache period.

The trigeminal innervation of the dura and its vessels has a prominent role in the mechanism of cluster headache. Nociceptin, an opioid neuropeptide, is the endogenous ligand of the OP-4 receptor, with both algesic and analgesic properties depending on the site of action. Nociceptin and its receptor are expressed by trigeminal ganglion cells where they co-localize with calcitonin gene-related peptide, a marker peptide of the trigeminovascular neurones. Nociceptin inhibits neurogenic dural vasodilatation, a phenomenon related to trigeminovascular activation. To explore its possible involvement in cluster headache, we studied circulating levels of nociceptin when attack-free during the cluster period, and also after the termination of the cluster period, using radioimmunoassay. In 14 cluster headache patients nociceptin levels during the cluster period were significantly lower than in age-, and sex-matched controls (4.91 +/- 1.96 vs. 9.58 +/- 2.57 pg/ml, P < 0.01). After the termination of the cluster period nociceptin levels (8.60 +/- 1.47 pg/ml) were not statistically different from controls. Nociceptin levels did not correlate with age, length of disease or episode length. Lower nociceptin levels during the cluster period may result in a defective regulation of trigeminal activity that might not protect sufficiently against the attacks.

Health-related and condition-specific quality of life in episodic cluster headache.

Health-related quality of life was studied in 35 episodic cluster headache (CH) patients during and after the cluster period, using a generic (SF-36) and a headache-specific (MSQ2.1) instrument. The results were compared with those of age- and sex-matched migraineurs (n = 53) and healthy persons (n = 62). During the cluster period patients had lower scores than controls in all SF-36 and MSQ2.1 domains. The difference was significant for most SF-36 and all MSQ2.1 domains. Although CH patients had lower scores than migraineurs on most scales, the difference was significant only on SF-36 scores measuring bodily pain and social functioning. There was a good correlation between the two instruments. After the termination of the cluster period the quality of life of patients was similar to that of headache-free controls. Generic and headache-specific QoL are severely impaired in CH and this impairment is at least as severe as in migraine.

Suboccipital cerebrospinal fluid and plasma concentrations of somatostatin, neuropeptide Y and beta-endorphin in patients with common migraine.

The somatostatin-like (SLI), the neuropeptide Y-like (NPY-LI), and the beta-endorphin-like (BE-LI) immunoreactivities of cerebrospinal fluid (CSF) obtained by suboccipital puncture, or plasma from patients suffering from common migraine or other neuropsychiatric disorders were analysed. The SLI concentration was tendentiously decreased in the migraine patients during the attack-free period compared to that of a 'mixed neuropsychiatric group'. During the migraine attack the level of SLI was further decreased. Similar alteration was found in the CSF BE-LI, while the BE-LI in the plasma showed only a tendentious decrease in common migraine patients. The NPY-LI did not change during the attack period in the CSF or plasma. These findings may indicate the possible role of somatostatin in the pathogenesis of common migraine, and support earlier observations that beta-endorphin is involved in the development in this disorder.

Cerebrospinal fluid (CSF) investigations in migraine.

A normal cell count as well as normal CSF pressure levels were found in both classic and common migraine patients during and between attacks. Total protein content was significantly lower in the migraine patients than in the controls, but no changes were found in the CSF protein fractions. The CSF 5-hydroxyindoleacetic acid level of the migraine patients proved to be higher than in the controls, whereas the homovanillic acid concentration was within the control limits.