First Measurement of a Long-Lived π

The adapted DIRAC experiment at the CERN PS accelerator observed for the first time long-lived hydrogenlike π^{+}π^{-} atoms, produced by protons hitting a beryllium target. A part of these atoms crossed the gap of 96 mm between the target and a 2.1 µm thick platinum foil, in which most of them dissociated. Analyzing the observed number of atomic pairs, n_{A}^{L}=436_{-61}^{+157}|_{tot}, the lifetime of the 2p state is found to be τ_{2p}=(0.45_{-0.30}^{+1.08}|_{tot})×10^{-11} s, not contradicting the corresponding QED 2p state lifetime τ_{2p}^{QED}=1.17×10^{-11} s. This lifetime value is three orders of magnitude larger than our previously measured value of the π^{+}π^{-} atom ground state lifetime τ=(3.15_{-0.26}^{+0.28}|_{tot})×10^{-15} s. Further studies of long-lived π^{+}π^{-} atoms will allow us to measure energy differences between p and s atomic states and so to discriminate between the isoscalar and isotensor ππ scattering lengths with the aim to check QCD predictions.

Observation of π

The observation of hydrogenlike πK atoms, consisting of π^{-}K^{+} or π^{+}K^{-} mesons, is presented. The atoms are produced by 24 GeV/c protons from the CERN PS accelerator, interacting with platinum or nickel foil targets. The breakup (ionization) of πK atoms in the same targets yields characteristic πK pairs, called "atomic pairs," with small relative momenta Q in the pair center-of-mass system. The upgraded DIRAC experiment observed 349±62 such atomic πK pairs, corresponding to a signal of 5.6 standard deviations. This is the first statistically significant observation of the strange dimesonic πK atom.

Elective segmental ureterectomy for transitional cell carcinoma of the ureter: long-term follow-up in a series of 73 patients.

UNLABELLED: What's known on the subject? and What does the study add? Upper Urinary Tract (UUT) Transitional Cell Carcinoma (TCC) is an uncommon disease and represents approximately 5% of all urothelial carcinomas. We report our series on 73 patients treated with Kidney Sparing Surgery for UUT TCC. Good results have been achieved in terms of oncological outcome comparing this conservative approach to the radical nephrourectomy. OBJECTIVES: • To report the long-term oncological outcome in patients with transitional cell carcinoma of the ureter electively treated with kidney-sparing surgery. • To compare our data with the few series reported in the literature. PATIENTS AND METHODS: • We considered 73 patients with transitional cell carcinoma of the distal ureter treated in five Italian Departments of Urology. • The following surgeries were carried out: 38 reimplantations on psoas hitch bladder (52%), 21 end-to-end anastomoses (28.8%), 11 direct ureterocystoneostomies (15.1%) and three reimplantations on Boari flap bladder (4.1%). • The median follow-up was 87 months. RESULTS: • Tumours were pTa in 42.5% of patients, pT1 in 31.5%, pT2 in 17.8% and pT3 in 8.2%. • Recurrence of bladder urothelial carcinoma was found in 10 patients (13.7%) after a median time of 28 months. • The bladder recurrence-free survival at 5 years was 82.2%. • The overall survival at 5 years was 85.3% and the cancer-specific survival rate at 5 years was 94.1%. CONCLUSION: • Our data show that segmental ureterectomy procedures do not result in worse cancer control compared with data in the literature regarding nephroureterectomy.

Comparison between Two Different Two-Stage Transperineal Approaches to Treat Urethral Strictures or Bladder Neck Contracture Associated with Severe Urinary Incontinence that Occurred after Pelvic Surgery: Report of Our Experience.

Introduction. The recurrence of urethral/bladder neck stricture after multiple endoscopic procedures is a rare complication that can follow prostatic surgery and its treatment is still controversial. Material and Methods. We retrospectively analyzed our data on 17 patients, operated between September 2001 and January 2010, who presented severe urinary incontinence and urethral/bladder neck stricture after prostatic surgery and failure of at least four conservative endoscopic treatments. Six patients underwent a transperineal urethrovesical anastomosis and 11 patients a combined transperineal suprapubical (endoscopic) urethrovesical anastomosis. After six months the patients that presented complete incontinence and no urethral stricture underwent the implantation of an artificial urethral sphincter (AUS). Results. After six months 16 patients were completely incontinent and presented a patent, stable lumen, so that they underwent an AUS implantation. With a mean followup of 50.5 months, 14 patients are perfectly continent with no postvoid residual urine. Conclusions. Two-stage procedures are safe techniques to treat these challenging cases. In our opinion, these cases could be managed with a transperineal approach in patients who present a perfect operative field; on the contrary, in more difficult cases, it would be preferable to use the other technique, with a combined transperineal suprapubical access, to perform a pull-through procedure.

Effects of the cannabinoid antagonist SR 141716 on sexual and motor behaviour in receptive female rats.

1. The aim of the present study was to investigate the effect of the cannabinoid antagonist/inverse agonist SR 141716 (SR) on the receptive behaviour and sexual motivation of female rats. 2. Partner preference, receptivity and proceptivity were evaluated in ovariectomized female rats primed with oestrogen and progesterone and administered SR (1 or 2.5 mg/kg, i.p.) 20 min prior to testing. 3. In the partner preference test, a reduced interest in both stimulus animals (a sexually active male and an ovariectomized hormone-primed female) was detected in rats treated with SR at both doses, but no effect on preference score was observed. In the receptivity test, pronounced reductions in lordosis quotient, lordosis rating and in the percentage of receptive females were found in SR-treated rats compared with control rats. Proceptive behaviours were not significantly affected by either dose of SR. 4. In addition, we explored the behavioural effects induced by SR in female rats using the open field test. Only at the higher dose (i.e. 2.5 mg/kg) did SR markedly increased grooming and scratching behaviour. 5. The results demonstrate the ability of SR to reduce female sexual receptivity, but not sexual motivation. The reduction does not seem strictly related to the motor alterations induced by the cannabinoid antagonist.

Influence of Griffonia simplicifolia on male sexual behavior in rats: behavioral and neurochemical study.

The seeds of Griffonia simplicifolia Baill. are rich in 5-HTP (5-hydroxytryptophan), a direct precursor of the neurotransmitter serotonin. In the present study we investigated the influence of the plant extract on male sexual behavior. The seed extract was orally administered to Sprague-Dawley male rats at three dose levels (25, 50 and 100 mg/kg) both acutely and subchronically (daily for 9 days). Mating test with receptive female rats was performed 60 min after the acute treatment or the last dose when repetitively administered. Mount, intromission and ejaculation latencies and post-ejaculatory interval were recorded. Food intake and body weight were measured over the 9-day period of treatment. Microdialysis technique was used to detect the extracellular levels of serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in rat brain following the acute administration of the extract dosed at 100mg/kg. The acute treatment significantly increased mount latency (at any dosage), intromission and ejaculation latencies (at 100 mg/kg) and post-ejaculatory interval (at 50 and 100 mg/kg). On the contrary the subchronic treatment failed to exert a significant influence on copulatory behavior. The daily administration of the extract dosed at 50 and 100 mg/kg for 9 days significantly reduced food intake and body weight. Finally in the microdialysis experiments we found a dramatic increase in 5-HT and its metabolite 5-HIAA.

Experimental study on Satureja montana as a treatment for premature ejaculation.

AIM OF THE STUDY: Satureja montana (winter savory) is a medicinal plant traditionally used to treat different disorders including male sexual dysfunction. In this study we evaluated the effect of Satureja montana hydroalcoholic extract on copulatory behavior of sexually potent male rats. MATERIALS AND METHODS: The extract was orally administered acutely or repetitively for 8 consecutive days at the doses of 25 and 50 mg/kg. The main parameters of sexual behavior, mount (ML), intromission (IL), ejaculation (EL) latencies and post-ejaculatory interval (PEI), were evaluated in animals submitted to mating test and multiple ejaculations test. Testosterone serum levels were measured in rats acutely treated with Satureja montana extract dosed at 50 mg/kg. In addition the open field test was conducted to evaluate the locomotor behavior. RESULTS: When acutely administered at both dosages, the extract was able to significantly increase EL and decrease intromission frequency (IF) in comparison with controls. The significant increase in EL was found also when the extract was subacutely administered, daily for 8 consecutive days, at the dose of 25 mg/kg. In the multiple ejaculations test, EL values of treated rats were significantly increased during the 1st and 2nd sequence in comparison with controls; in addition only rats treated with the extract were able to reach the 4th ejaculation within 30 min. Testosterone serum level measured in rats acutely treated with Satureja montana at the dose of 50 mg/kg was significantly increased in rats in comparison with controls. Finally, the locomotor activity recorded in the open field test was not affected by the acute administration of the plant extract. CONCLUSIONS: These data suggest that Satureja montana could be considered as a natural remedy for the treatment of premature ejaculation delaying ejaculation latency without exerting any negative effect on the other parameters of sexual behavior and without exerting a sedative effect. In addition the increased serum level of testosterone confirms the positive influence of Satureja montana on male sexual function.

Griffonia simplicifolia negatively affects sexual behavior in female rats.

At present Griffonia simplicifolia is used in food supplement aimed to treat mood disorders as well as to reduce food intake and body weight. The plant has gained increasing interest for its high content in 5-hydroxy-L-tryptophan (5-HTP) particularly in the seed. The present study was designed to evaluate the influence of a seed extract of the plant, dosed at 25, 50 and 100 mg/kg, on the sexual behavior of ovariectomized hormone-primed rats after acute and subchronic treatment. The single administration of G. simplicifolia significantly reduced lordosis response and increased rejection behavior in female rats treated with the highest dose while it did not influence proceptive behaviors. On the other hand the subchronic administration of the extract significantly reduced proceptivity but not receptivity, and increased rejection behavior. All the tested dosages were able to markedly decrease food intake and body weight after a 9-day treatment. Taken together the present results, possibly ascribed to increased levels of 5-hydroxytryptamine (5-HT) in the brain, suggest a cautious administration of the plant extract owing to its negative influence on female sexual behavior.

Experimental evidence of the anaphrodisiac activity of Humulus lupulus L. in naïve male rats.

ETHNOPHARMACOLOGICAL RELEVANCE: In the folk medicine Humulus lupulus L. (hops) is mainly recommended as a mild sedative with antispasmodic and digestive properties. It is also reputed to exert an anaphrodisiac effect but it is still lacking the experimental evidence of this activity. AIM OF THE STUDY: To evaluate the influence of Humulus lupulus extract on sexual behavior of both naïve and sexually potent male rats; thereafter to investigate the role of 8-prenylnarigenin (8-PN) in the effect displayed by the hop extract. MATERIALS AND METHODS: Sprague-Dawley male rats both naïve and sexually potent were acutely administered with the hop extract dosed at 5, 10, 25 and 50 mg/kg. In addition the extract was administered daily for 10 consecutive days at the dose of 0.25 mg/kg/day in sexually potent animals. The pure compound 8-PN was acutely administered in naïve rats at the dosages of 5, 12.5 and 25 microg/kg. All the animals were screened for their sexual behavior manifestation during the mating test. RESULTS: In naïve rats the acute administration of Humulus lupulus extract at the doses of 25 and 50 mg/kg significantly reduced the percentage of mounting and ejaculating animals, in comparison to vehicle controls. The other parameters recorded during the mating test were not affected by the hop extract. In sexually potent rats nor the acute neither the repeated administration of the extract modified their copulatory behavior. The pure compound 8-PN failed to influence male sexual behavior of naïve rats. CONCLUSION: Humulus lupulus extract exerted an anaphrodisiac effect only in naïve rats by inhibiting their mounting and ejaculating behavior. The presence of 8-PN in the extract could be only partially involved in the observed anaphrodisiac effect.

The phytoestrogen ferutinin improves sexual behavior in ovariectomized rats.

The present study was designed to examine the effect of ferutinin chronic administration on sexual behavior of ovariectomized non-estrogen-primed rats. Starting from 3 weeks after ovariectomy, female rats were orally treated with ferutinin at the doses of 0.2 and 0.5 mg/kg, daily for 4 weeks. Ferutinin's effect was compared with that of estradiol benzoate, subcutaneously injected at the dose of 1.5 microg/rat twice a week. Animals were tested for sexual motivation, receptivity and proceptivity after 1, 2 and 3 weeks of treatment and for paced mating behavior after 4 weeks of treatment. Before each experimental test, they received progesterone injection (500 microg/rat). Both dosages of ferutinin significantly increased the receptive behavior in a time-dependent manner, as well as estradiol benzoate did. Also proceptive behaviors increased in ferutinin-treated animals in comparison with control ones. During the partner preference test ferutinin was able to induce a significant preference for a sexually active male over a sexually receptive female. Moreover, ferutinin restored a normal paced mating behavior, which had been suppressed by ovariectomy. These results show that ferutinin exerts an estrogenic activity in ovariectomized non-estrogen-primed female rats.

Assessment of pulmonary function in patients before and after laparoscopic and open esophagogastric surgery.

BACKGROUND: Laparoscopy is a technique used in various surgical procedures. Few studies in the literature compare stress between laparoscopic and open surgery used for esophagogastric surgical procedures. Pulmonary function is known to be significantly affected in open surgeries, increasing postoperative morbidity and mortality. The current study aimed to assess pulmonary function in patients before and after open and laparoscopic esophagogastric surgery. METHODS: For this study, 75 patients were divided into two groups: 50 patients undergoing laparoscopy and 25 patients undergoing open surgery. The following parameters were determined by spirometry before and after surgery: forced expiratory volume in the first second (FEV(1)), forced vital capacity (FVC), and forced expiratory flow in the midexpiratory phase (FEF(25-75%)). RESULTS: A decrease in FEV(1,) FVC, and FEF((25-75%)) was observed in the two groups on postoperative days 2, 3, and 4, as compared with the preoperative period. Likewise, FEV(1) and FVC showed a significant reduction on postoperative days 2, 3, and 4 in the patients who underwent to open surgery, but only on the day 2 in those who underwent to laparoscopic surgery. A significant decrease in FEF((25-75%)) was observed only on postoperative day 2 in the group that underwent open surgery. Significant differences in FEV(1) between the groups were observed on postoperative days 2, 3, and 4. No significant difference in FVC was noted between the groups, and a difference in FEF((25-75%)) was observed only on postoperative day 4. CONCLUSIONS: Postoperative pulmonary dysfunction was more important for the patients undergoing open surgery than for those undergoing laparoscopic surgery.

Opposite effect of acute and subchronic treatments with Ferula hermonis on copulatory behavior of male rats.

Sexually potent and sluggish/impotent male rats were orally treated with an extract of Ferula hermonis (30 and 60 mg/kg). The acute administration stimulated sexual motivation in potent rats and improved copulatory performance in sluggish/impotent rats. This last effect was elicited only by the higher dose, which, in parallel, increased serum testosterone levels in rats. On the contrary, when the extract was subchronically administered (10 days) a marked reduction in the percentage of rats achieving ejaculation was detected, together with a general impairment of the copulatory pattern. Furthermore, the repeated administration of the extract (6 mg/kg/day for 10 days) resulted in a significant reduction of testosterone levels in comparison with controls. The present results discourage a repeated assumption of F. hermonis, while suggesting its acute administration to improve the performance in sexual dysfunctions.

Pharmacological manipulation of brain galaninergic system and sexual behavior in male mice.

RATIONALE: Available data suggest a complex role for the brain galaninergic system in male sexual behavior; however, the results so far obtained in animals with either galanin or galanin antagonists are conflicting. OBJECTIVE: To define the better influence of galanin on male sexual behavior by studying, in mice, (i) the effect of galanin and of the chimeric galanin peptide M40 on the copulatory performance, and (ii) galanin mRNA levels in hypothalamic arcuate and dorso-medial nuclei. METHODS: For the behavioral testing, only sexually sluggish male mice were used. Galanin mRNA levels were studied in both sexually potent and impotent mice by means of in situ hybridization. Standard behavioral parameters for sexual behavior were recorded or calculated. Synthetic galanin (0.05, 0.1 or 1 microg/mouse) and M40 (5 or 20 microg/mouse) were intracerebroventricularly (ICV) injected, 15 min before the copulatory test. Galanin mRNA levels were evaluated. RESULTS: In sexually sluggish male mice, both galanin (0.1 and 1 microg/mouse ICV) and M40 (20 microg/mouse ICV), significantly increased intromission frequency and ejaculation latency; M40 also improved copulatory efficacy. On the other hand, in the hypothalamic arcuate and dorso-medial nuclei, the levels of galanin mRNA were not significantly different in sexually potent and impotent male mice. CONCLUSIONS: These results show that in sexually sluggish male mice the ICV injection of either galanin or the chimeric analogue M40 greatly prolongs the duration of the copulation; without a reduction of the sexual drive or of the copulatory performance. On the other hand, the hybridization experiments seem to rule out an important physiological role of the brain galaninergic system in the regulation of male sexual behavior, at least in mice.

Influence of estrogens and oxytocin on germ cells death in the neonatal mammalian ovary.

During mammalian oogenesis, some processes involve proliferation and others drastic reduction of germ cells. This study reports on the role played by two hormones, estradiol monobenzoate and oxytocin, in the control of the number of germ cells in the neonatal mouse ovary. Female neonatal mice were treated with doses ranging between 0.1 and 1 microg/mouse of estradiol monobenzoate or oxytocin and sacrificed at 5 days of postnatal age. The results showed that in the animals treated with estrogen, follicular development was more advanced than that of controls. Further the number of germ cells in apoptosis was drastically reduced. In the animals treated with oxytocin, the follicular development was arrested at the stage of primary follicles. In addition, the number of apoptotic germ cells increased if compared with that of the controls.

Influence of SAMe on the modifications of brain polyamine levels in an animal model of depression.

The mechanism(s) of the antidepressant activity of S-adenosyl-L-methionine (SAMe) have not yet been elucidated. SAMe is essential for the synthesis of polyamines, which have a key role in protein synthesis, cell proliferation, and neuronal plasticity. On the other hand, accumulating data indicate that depression is associated with a reduction in regional brain volume and that antidepressants increase neurogenesis in defined brain regions and also influence neuronal plasticity. Here we show that in a validated rat model of depression (chronic unpredictable mild stress-induced anhedonia) there is a significant reduction of putrescine, spermidine and spermine in the hippocampus, and of only putrescine in the nucleus accumbens septi. SAMe, at a fully antidepressant dose (300 mg/kg i.m., daily for 7 days), completely restores the levels of putrescine in the nucleus accumbens, and restores in part the levels of both spermidine and spermine in the hippocampus. These results may suggest (i) a role for brain polyamines in depression and in reward processes, and (ii) that the antidepressant effect of SAMe may be due, at least in part, to a normalization of putrescine levels in the nucleus accumbens septi.

Effects of estrogens and oxytocin on the development of neonatal mammalian ovary.

The preservation and death of germ cells in the neonatal mammalian ovary are linked with the presence of hormones. Estrogens and oxytocin are present at birth in all mammalian vertebrates. The aim of this study was to examine their role in the development of the neonatal ovary and also in the preservation and death of germ cells in the neonatal period: apoptotic phenomena play a fundamental role in the control of their number. Female neonatal mice were treated at birth with estradiol monobenzoate or oxytocin and sacrificed after 5 days. The ovaries were sectioned in toto into semi-thin sections, in order to calculate their volume. Thin sections were also carried out to verify, under the transmission electron microscope (T.E.M.), the cells in apoptosis. The ovaries treated with the greater concentration of estradiol monobenzoate showed a volume that was significantly greater than that of the controls and a reduction of germ cells in apoptosis. The ovaries treated with oxytocin at all degrees of concentration had a volume significantly less than the controls and they also had a higher number of germ cells in apoptosis.

Behavioral and developmental outcomes of prenatal and postnatal vanadium exposure in the rat.

The developmental and behavioral outcomes of uninterrupted exposure to vanadium was studied in the rat. Starting 3 days before birth and up to the 100th day of extrauterine life, rats received as drink either a water solution of vanadyl sulphate (300 mg l(-1)containing 70 mg l(-1)of vanadium element, which is equal to an ingested dose of about 10 mg kg(-1)per day of vanadium element) plus NaCl 5 g l(-1), or a water solution of NaCl 5 g l(-1), or plain water [up to weaning (25th day of extrauterine life) treatment was given to dams and offspring]. At weaning, survivors were fewer and body weight was found to be significantly lower in the offspring of vanadium plus NaCl-treated dams than in the offspring of the other two groups. After weaning, growth retardation continued to be significant in both vanadium plus NaCl- and NaCl-treated rats. Such an effect was more pronounced in males than in females. Locomotor activity--evaluated at 1 month of age--was not significantly different in the three groups of rats. In the open-field, male (but not female) vanadium plus NaCl-treated rats had a reduced outer ambulation, rearing posture and grooming activity, and an increased defecation, in comparison with the males of the NaCl group, and reduced rearing in comparison with control males. As concerns ingestive behaviors, the only significant datum was an increased water intake in NaCl-treated males. Finally, at the 100th day of life, working memory was significantly impaired in both vanadium plus NaCl- and NaCl-treated rats.

[In vitro study of periodontal ligament cells]. / Studio in vitro delle cellule del legamento periodontale.

BACKGROUND: The aim of this research is to outline a procedure able to promote specific cellular differentiation and proliferation with consequent periodontal regeneration. To achieve this goal, use was made of various compounds supposed to have the capacity of aiding periodontal regeneration. METHODS: The cells utilised for this study were obtained from explants of human periodontal ligaments. Their proliferation and differentiation capacity was examined in the presence of: coral granules (350, 500 mu), collagene type 1, growth factors (Platelet derived growth factor, PDGF and Transforming growth factor beta 1, TGF beta 1), both on their own and in different combination with one another. The differentiation activity was evaluated by ultrastructural morphological method (Transmission electron microscope-TEM) and by spectrophotometric investigation of the alkaline phosphatasis (ALP). RESULTS: The data show that the coral granules and among the growth factors used only TGF beta 1 stimulate the differentiation activity of the periodontal ligament cells valued on the basis of their capacity of producing ALP. These data are supported by the observation with TEM. CONCLUSIONS: From these results it is suggested that there may be therapeutic efficiency in the periodontal field of substances promoting cellular proliferation and differentiation.

L -sulpiride, at antidepressant dosage, prevents conditioned-fear stress-induced gastric lesions in rats.

It has been previously shown that long-term treatment with low doses of l-sulpiride is highly effective in rat models of depression and of anticipatory anxiety/panic behavior. The present study was aimed at investigating whether the same treatment can prevent the ulcerogenic effect of repeated inescapable stresses. In adult rats, the repeated (7 consecutive days) exposure to an uncontrollable stressful condition (inescapable 2.5 mA scrambled shock for 60 s) produced the development of gastric lesions (multiple punctiform telangiectasias in all rats, with superficial erosions or more severe ulcerations in 10 out 13 rats; score 4.67 +/- 0.44). l-sulpiride, intraperitoneally injected once a day at an antidepressant dose level (4 mg kg(-1) per day), starting 21 days before the beginning of the 7-day sequence of inescapable punishments ( = 28 daily treatments), almost completely prevented the stress-induced gastric injury (score 1.67 +/- 0.29; P< 0.001 vs saline-treated rats, Mann-Whitney U test). These results show that, in rats, a long-term treatment with low doses of l-sulpiride prevents the development of gastric lesions induced by chronic exposure to uncontrollable stress.

Acute low doses of melatonin stimulate rat sex behavior: the role of serotonin neurotransmission.

Melatonin is known to inhibit male and female sex behavior, but this effect has been reported only after repeated administration of sustained doses of the hormone. The present experiments were performed in order to study the effects of acute treatment with low doses of melatonin on rat male and female sex behavior in a dose-response paradigm. After four mating tests with a receptive female, sexually active male rats of the Wistar strain were injected intraperitoneally (i.p.) with small doses of melatonin (10, 50 and 100 microg/kg) administered acutely 1 h before a 30-min mating test. Melatonin (50 and 100 ng/2 microl) or its analogs, 6-chloromelatonin (2 and 4 ng/2 microl) and 2-iodomelatonin (5 and 10 ng/2 microl) were also injected intracerebroventricularly (i.c.v.) 30 min before mating. Either treatments caused a reduction of the latency to the first mount, intromission and ejaculation. An increase in the frequency of mounts, intromissions and ejaculations was also observed. Inhibition of sexual activity was observed when a greater dose (1 mg/kg) of melatonin was repeatedly injected for 14 days. Female sex behavior, measured by the lordosis quotient in Wistar female rats, was not affected by acute treatment with the hormone, while it appeared to be inhibited by the repeated injection. The facilitating effect of acute i.p. or i.c.v. melatonin low doses on sexual activity of male rats was partially abolished by the pre-treatment with the non-selective melatonin antagonist, luzindole (0.25 mg/kg, injected subcutaneously), and totally suppressed by the injection of small quantities of serotonin or the 5H(2A)-5H(2C) receptor agonist, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane into the amygdala. These results suggest that melatonin may exert opposite effects on male and female sex behavior depending on the dose and duration of treatment.