Identification of the endosymbionts from Sulla spinosissima growing in a lead mine tailings in Eastern Morocco as Mesorhizobium camelthorni sv. aridi.

AIMS: To identify the bacteria nodulating Sulla spinosissima growing profusely in a lead and zinc mine tailings in Eastern Morocco. METHODS AND RESULTS: In all, 32 rhizobial cultures, isolated from root nodules of S. spinosissima growing in soils of the mining site, were tolerant to different heavy metals. The ERIC-polymerase chain reaction (PCR) fingerprinting analysis clustered the isolates into seven different groups, and the analysis of the 16S rRNA sequences of four selected representative strains, showed they were related to different species of the genus Mesorhizobium. The atpD, glnII and recA housekeeping genes analysis confirmed the affiliation of the four representative strains to Mesorhizobium camelthorni CCNWXJ40-4T , with similarity percentages varying from 96·30 to 98·30%. The sequences of the nifH gene had 97·33-97·78% similarities with that of M. camelthorni CCNWXJ40-4T ; however, the nodC phylogeny of the four strains diverged from the type and other reference strains of M. camelthorni and formed a separated cluster. The four strains nodulate also Astragalus gombiformis and A. armatus but did not nodulate A. boeticus, Vachellia gummifera, Prosopis chilensis, Cicer arietinum, Lens culinaris, Medicago truncatula, Lupinus luteus or Phaseolus vulgaris. CONCLUSIONS: Based on similarities of the nodC symbiotic gene and differences in the host range, the strains isolated from S. spinosissima growing in soils of the Sidi Boubker mining site may form a different symbiovar within Mesorhizobium for which the name aridi is proposed. SIGNIFICANCE AND IMPACT OF THE STUDY: In this work, we show that strains of M. camelthorni species nodulating S. spinosissima in the arid area of Eastern Morocco constitute a distinct phylogenetic clade of nodulation genes; we named symbiovar aridi, which encompasses also mesorhizobia from other Mediterranean desert legumes.

A standardized method to assess the endogenous activity and the light-response of the retinal clock in mammals.

Purpose: The bioluminescence reporter PER2::Luciferase (PER2::Luc) provides a powerful tool to study the regulation of biological clocks in explant tissues, including the retinal clock. However, the establishment of a standardized procedure to replicate experimental conditions and to enable meaningful comparisons between findings from different studies is still lacking. In addition, different parameters may affect the retinal circadian bioluminescence signal and its dynamic in in vitro assays. In the present study, we first evaluated the effect of sex and age on the main parameters of the mouse retinal clock. We then examined the impact of medium change on PER2::Luc rhythm and compared two light stimulation protocols of the retinal clock. Methods: In a first set of experiments, retinal explants from both male and female Per2Luc mice of different ages (1 to 8 months) are cultured and the period, phase, amplitude, and rhythmic power of PER2::Luc oscillations are analyzed. In a second set of experiments, we quantified the effect of a medium change done after 4, 6, 8, 9, or 10 days of culture on the phase and period of retinal explants. Finally, we compared the phase shift and the period change resulting from two methods of light stimulations of retinal explants: the first involved the transfer of the cultured tissues from the Lumicycle into a light stimulation chamber, while the second used a light delivery apparatus embedded in the Lumicycle. Results: We do not observe any sex-dependent effects on the amplitude, period, phase, and rhythmic power of the in vitro retinal PER2::Luc oscillations in animals aged of 2 to 3 months. The most remarkable effect of age is on the amplitude of PER2::Luc oscillations that significantly decrease from 1 to 4-5 months, whereas the endogenous period and rhythmic power increase slightly until 2 to 3 months and then do not change until 8 months. The phase is not affected by age. We then show that a medium change occurring after 4 days of culture does not alter the phase of PER2::Luc rhythm by comparison with day 0, whereas a medium change done after 6, 8, 9, or 10 days in culture advances the phase and lengthens the period. Finally, we observe that the physical displacement of the culture dishes containing retinal explants, even in complete darkness, induces a strong phase shift of PER2::Luc oscillations. Conclusions: Our work shows that the retina cultures are particularly sensitive to some aspects of the culture procedure, and it provides an accurate standard protocol to avoid biases due to artifactually induced phase shifts resulting from the medium change or physical displacement.

Effects of Single Cage Housing on Stress, Cognitive, and Seizure Parameters in the Rat and Mouse Pilocarpine Models of Epilepsy.

Many experimental approaches require housing rodents in individual cages, including in epilepsy research. However, rats and mice are social animals; and individual housing constitutes a stressful situation. The goal of the present study was to determine the effects of individual housing as compared to conditions maintaining social contact on stress markers and epilepsy. Control male mice socially housed during pretest and then transferred to individual cages for six weeks displayed anhedonia, increased anxiety and biological markers of stress as compared to pretest values or mice kept socially housed during six weeks. Pilocarpine (pilo)-treated mice housed together showed increased levels of anhedonia, anxiety and stress markers as well as decreased cognitive performance as compared to the control group. The differences were more significant in pilo-treated mice housed individually. Anxiety correlated linearly with cognitive performance and stress markers independently of the experimental conditions. In the male rat pilo model, seizures were sixteen times more frequent in singly housed animals as compared to animals kept in pairs. Daily interactions with an experimenter in otherwise singly housed animals was sufficient to produce results identical to those found in animals kept in pairs. We propose that social isolation produces a severe phenotype in terms of stress and seizure frequency as compared to animals maintaining social contact (at least in these two models), a factor that needs to be taken into account for data interpretation, in particular for preclinical studies.

Day surgery for anterior cruciate ligament reconstruction in children: a prospective study on feasibility and satisfaction.

PURPOSE: To evaluate the feasibility of day surgery anterior cruciate ligament reconstruction (ACLR) in children. Our hypothesis was that proper patient selection, adequate information and a streamlined clinical pathway would allow for a safe and satisfactory procedure. METHODS: A total of 20 patients, seven girls and 13 boys, who underwent outpatient ACLR at mean age of 14 years (8 to 16) were included in this single institution prospective case series. Surgery took place under simple general anesthesia while analgesia protocol combined local anesthesia, oral analgesics for the postoperative period and compressive cryotherapy. The main failure criterion was the inability to return home the day of surgery or the need for rehospitalization during the first week after discharge. Secondary evaluation parameters were the rate of postoperative complications, postoperative pain, quality of life (QOL) and patients' satisfaction outcome questionnaire (PSOQ) at postoperative day 1, 7 and 31. RESULTS: Of the 20 patients included, only one failed the ambulatory mode. The mean PSOQ score was, respectively for children and parents, 91.4% and 90.7% at day 7 and 94.6% and 95.7% at one month. Postoperative QOL at day 7 was very satisfying for all patients. Two minor early complications were reported. Both of the late complications, which included one partial wound dehiscence and one persistent knee swelling, resolved spontaneously. CONCLUSION: This study indicates that, in a targeted and well-informed population, day surgery for children ACLR yields high level of patient and family satisfaction in a safely manner. LEVEL OF EVIDENCE: IV, prospective case series.

Design of a multi-well plate for high-throughput characterization of heterogeneous catalysts by XRD, FT-IR, Raman and XRF spectroscopies.

For powder catalyst characterization, Fourier Transform Infrared (FTIR), Raman, and X-Ray Fluorescence (XRF) spectrometers and X-Ray Diffraction (XRD) are available in high-throughput (HT) configurations, for example at the REALCAT platform to sequentially analyse multiple sets of samples. To remove the bottleneck resulting from the use of different sample holders for each equipment, a unique multi-well plate was developed. This paper details the design of such a plate including the selection of the fabrication material and the plate dimensioning based on the study of the 4 different physical interactions between matter and electromagnetic radiations for the aforementioned techniques. This new plate consists of a holder for removable wells enabling the avoidance of cross-contamination between samples. Raman, a focusing technique, has no strict constraint on the plate design. The number of wells, their geometry, spacing and dimensions were adjusted to deal with the constraints of IR optics. The well depth was set according to the XRF maximum penetration depth in the sample. The well diameter was optimized in order to obtain from the X-ray spot size the maximum achievable intensity. Poly-methyl-methacrylate (PMMA) was chosen as the material for the new plate due to its amorphous structure (no peak in XRD analysis) and ease with which it can be cut by a laser. Finally, the flatness of the multi-well plate was validated on the most challenging instrument: XRD. This new plate allows fast sample filling/preparation, requires small quantities of catalyst (50 to 80 mg) in each well and is compatible and convenient for HT experimentation.

Management of acute sigmoid volvulus: short- and long-term results.

AIM: The best form of prophylactic management of a decompressed sigmoid volvulus (SV) is controversial especially in the elderly. We have studied our experience with this condition to assess the short- and long-term results of SV management. METHOD: All patients treated for SV in our department between 2003 and 2013 were retrospectively included. Emergency decompression was attempted in all patients in whom there was no sign of peritonitis. Planned surgical resection was the procedure of choice in young patients. Percutaneous endoscopic colopexy (PEC) was used in high surgical risk patients. RESULTS: There were 65 patients (45 males) of median age 71.5 (24-99) years. Non-surgical reduction was performed in 62 with a success rate of 95% (59/62). Recurrence after initial decompression was 67% at a median follow-up of 5 (1-14) years. A prophylactic surgical resection was performed with primary anastomosis in 33 patients. There were no deaths and the major morbidity rate was 6%. At a mean follow-up of 62 months, only 1 (3%) patient had had a recurrence (at 130 months). PEC was performed in six patients of median age 90 (84-99) years and with a median American Society of Anesthesiologists score of 4. Complications included local site infection (n = 2), pain (n = 1) and abdominal wall bleeding (n = 1). After a median follow-up of 2 (1-4) years, three patients died from medical causes and one recurrence occurred 13 months after removal of the PEC tube. CONCLUSION: Prophylactic treatment after initial decompression of SV results in a low rate of recurrence. Planned sigmoid resection is safe and effective. In frail elderly patients, PEC is satisfactory.

Lack of adenylate cyclase 1 (AC1): consequences on corticospinal tract development and on locomotor recovery after spinal cord injury.

Cyclic AMP (cAMP) signalling pathways are involved in axonal growth and regeneration. The calcium-calmodulin- stimulated adenylate cyclase 1 (AC1), a regulator of cAMP levels, is strongly expressed in the corticospinal motor neurons (CSMN) in cerebral cortex layer V during development, but its role in the development of the corticospinal tract (CST) is unknown. Here, we analyse the organization of the CST pathway using anterograde and retrograde tracers in the barrelless (brl) mouse that carries an inactivating mutation of the AC1 gene. We show that in brl mice the general organization of the CST is normal but there is an increase in the number of axons in the ipsilateral contingent in the dorsal and ventral medial funiculi of the cervical spinal cord. The density of CSMN in layer V of the motor cortex is increased in brl compared to wild-type mice. Thus, lack of AC1 likely perturbs late phases of CSMN and CST development. Next, we examine the motor recovery after a spinal cord injury (SCI). We find that brl mice show enhanced locomotor functions as assessed by the BMS (Basso mouse scale) as early as 6h and up to 6 weeks after SCI, indicating a smaller responsiveness of brl mice to SCI. It is therefore possible that developmental effects on motor systems might decrease the locomotor effects consecutive to a SCI. This point is particularly important with regards to the use of transgenic animals for testing SCI recovery.

Occurrence and determinants of poor response to short-term pre-operative erythropoietin treatment.

BACKGROUND: This study aimed to explore the occurrence and determinants of poor response to short-term pre-operative erythropoietin treatment and the effect of such poor response on transfusion in total hip arthroplasty patients. METHODS: We studied total hip arthroplasty patients who received erythropoietin before surgery. The primary outcome was the pre-operative increase in haemoglobin (delta haemoglobin) as response to erythropoietin therapy. Additionally, patients were classified in tertiles based on this delta haemoglobin: poor responders (cases), responders and good responders (controls) to erythropoietin. Patient characteristics, comedication and co-morbidity were collected as potential determinants of erythropoietin response. Regression techniques were used to estimate the strength of the associations and to assess the effect of poor response on transfusion requirement. RESULTS: A total of 379 patients receiving erythropoietin were eligible to enter the study. Mean delta haemoglobin was 19.3 g/l (standard deviation 9.4). Factors significantly associated with delta haemoglobin were the use of angiotensin II antagonists [-3.1 g/l; 95% confidence interval (CI) -5.7 to -0.6] and vitamin K antagonists (-6.9 g/l; 95% CI -10.0 to -0.2), together with body mass index (BMI) (-0.3 g/l per unit>; 95% CI -0.5 to -0.2). The additional case-control analysis yielded comparable results. Poor response to erythropoietin was associated with an increased transfusion risk (odds ratio 4.6, 95% CI 2.0-11). CONCLUSION: Use of angiotensin II receptor antagonists and vitamin K antagonists, and having a high BMI were determinants of poor response to short-term pre-operative erythropoietin treatment in total hip arthroplasty patients. Poor responders had a higher risk for perioperative blood transfusion.

Somali women and their pregnancy outcomes postmigration: data from six receiving countries.

OBJECTIVE: This study aimed to investigate pregnancy outcomes in Somali-born women compared with those women born in each of the six receiving countries: Australia, Belgium, Canada, Finland, Norway and Sweden. DESIGN: Meta-analyses of routinely collected data on confinements and births. SETTING: National or regional perinatal datasets spanning 3-6 years between 1997 and 2004 from six countries. SAMPLE: A total of 10 431 Somali-born women and 2 168 891 receiving country-born women. METHODS: Meta-analyses to compare outcomes for Somali-born and receiving country-born women across the six countries. MAIN OUTCOME MEASURES: Events of labour (induction, epidural use and proportion of women using no analgesia), mode of birth (spontaneous vaginal birth, operative vaginal birth and caesarean section) and infant outcomes (preterm birth, birthweight, Apgar at 5 minutes, stillbirths and neonatal deaths). RESULTS: Compared with receiving country-born women, Somali-born women were less likely to give birth preterm (pooled OR 0.72, 95% CI 0.64-0.81) or to have infants of low birthweight (pooled OR 0.89, 95% CI 0.82-0.98), but there was an excess of caesarean sections, particularly in first births (pooled OR 1.41, 95% CI 1.25-1.59) and an excess of stillbirths (pooled OR 1.86, 95% CI 1.38-2.51). CONCLUSIONS: This analysis has identified a number of disparities in outcomes between Somali-born women and their receiving country counterparts. The disparities are not readily explained and they raise concerns about the provision of maternity care for Somali women postmigration. Review of maternity care practices followed by implementation and careful evaluation of strategies to improve both care and outcomes for Somali women is needed.

Radiofrequency ablation for recurrent pelvic cancer.

OBJECTIVE: Local recurrence of pelvic cancer is a therapeutic challenge. The purpose of the study was to evaluate radiofrequency ablation (RFA, intra-operative or CT-guided) for the treatment of pelvic recurrence in patients not eligible for curative surgical resection. METHOD: Charts of all patients treated for pelvic recurrence by RFA between March 2004 and March 2005 were reviewed. RESULTS: Eight patients (two females) had RFA for inoperable local recurrence [rectal adenocarcinoma (six) and sarcoma (two)]. Surgical resection of the primary tumour had been performed at a median age of 50.2 (36.7-61.6) years. Recurrence occurred after a median of 49.5 (11.7-63.5) months. The mean size of the recurrence was 33.4 (20-45) mm. RFA was given on a median number of two occasions (1-3). Complications occurred in six patients including minor pain [pelvic (six); sciatic nerve irritation (four)]; ureteric obstruction requiring stenting (two) and colo-vesical fistula (one), requiring ileal urinary diversion. After a median follow-up of 18.2 months (11-32), six patients were still alive. Patients, who had experienced pain prior to RFA were pain-free. Five patients showed evidence of further tumour growth but were asymptomatic. CONCLUSION: Radiofrequency ablation is a feasible therapeutic option for recurrent pelvic cancer. It allows good symptom control in patients with pain but morbidity is high.

Colorectal neoplasia in Crohn's colitis: a retrospective comparative study with ulcerative colitis.

AIMS: To determine the clinicopathological features of colorectal cancer (CRC) in Crohn's disease (CD). METHODS AND RESULTS: All histological slides from surgical specimens with inflammatory bowel disease-related colorectal neoplasia examined in our hospital between 1990 and 2005 were reviewed. We identified 18 CRCs in 16 patients with CD and compared them with 57 CRCs in 41 patients with ulcerative colitis (UC). We also studied 25 patients with dysplasia without cancer (CD 2, UC 23). When CD and UC were compared, the median age at diagnosis of cancer (CD 52 years, UC 51 years), the frequency of mucinous adenocarcinoma (CD 16.7%, UC 17.5%) and the frequency of dysplasia adjacent to and distal from cancer (CD 56.3 and 37.5%, UC 65.8 and 39%, respectively) were similar. All neoplastic lesions occurred in areas affected by inflammatory bowel disease. CONCLUSIONS: CRC complicating CD and UC shares many clinicopathological features, in particular similar frequencies of dysplasia, both adjacent and distal, with cancer. Thus, surveillance for patients with Crohn's colitis should be similar to that for patients with UC. Consideration should be given to a more extensive UC-like surgical approach instead of segmental resection of the involved area.

The postnatal development of the optic nerve of a reptile (Vipera aspis): A quantitative ultrastructural study.

The number of axons in the optic nerve of the ovoviviparous reptile Vipera aspis was estimated from electron micrographs taken during the first 5 weeks of postnatal life. One to two days after birth, the optic nerve contains about 170,000 fibres, of which about 9% are myelinated. At the end of the fifth postnatal week, the number of optic fibres has fallen to about 100,000, of which about 42% are myelinated. This fibre loss continues after the fifth postnatal week, since in the adult viper the nerve contains about 60,000 fibres, of which 85% are myelinated; overall, about 65% of the optic nerve fibres present at birth disappear before the number of axons stabilises at the adult level. This study shows, for the first time, that the mode of development of the visual axons of reptiles is not that of anamniote vertebrates but similar to that of birds and mammals.

Calbindin, calretinin and parvalbumin immunoreactivity in the retina of the chameleon (Chamaeleo chamaeleon).

Apart from the pioneering studies of Ramon y Cajal [1893] and Rochon-Duvigneaud [1943], few studies have been devoted to the detailed study of the cytological and biochemical structure of the chameleon retina. In the present study we analyzed the expression of calbindin (CB), calretinin (CR) and parvalbumin (PV) immunoreactivities in the chameleon retina, and compared their distribution with those found in the retinas of other vertebrate species. CB immunoreactivity is dense in photoreceptors, horizontal and some lower amacrine cells. The most intense immunoreactivity was observed for calretinin; CR-ir amacrine cells are distributed throughout the inner nuclear, inner plexiform, and ganglion cell layers of the retina. Horizontal cells also display immunoreactivity to CR. A few retinal interneurons are weakly PV-ir. Double-labeling shows that all PV-ir or CB-ir cells, except the photoreceptors, are also strongly CR-ir. The distributions of these calcium-binding proteins in the chameleon retina share similarities with those observed in mammalian and avian retinas. In addition, the widespread distribution and co-localization of CB and CR reinforces the idea that these proteins play a general role in buffering the intracellular calcium levels in retinal cells. Furthermore, CB- and CR-immunoreactivities have enabled us to identify for the first time axon-bearing horizontal cells in the peripheral retina of the chameleon, very similar to those described in mammals.

Gamma-aminobutyric acid-synthesizing cells in the retina of the chameleon Chamaeleo chameleon.

Antibodies directed against gamma-aminobutyric acid (GABA) and L-glutamic acid decarboxylases 65 and 67 kDa (GAD65 and -67) were used to study the GABAergic cell populations of the chameleon retina. GABA immunoreactivity was found in the two main types of retinal interneurons, amacrine and horizontal cells. Amacrine, displaced amacrine, and intra- and interplexiform cells displayed the strongest GABA immunoreactivity of all the retinal cell types. Horizontal cells formed a continuous GABA-immunoreactive cell layer lying against the outermost portion of the inner nuclear layer. In contrast to previous studies (Quesada et al. [1996] Cell Biol. Int. 20:395-400; [1999] Eur. J. Anat. 3:13-25), the present results demonstrate that the horizontal cells of the chameleon retina are GABA immunoreactive and that a subpopulation of these is immunolabelled by an antibody against GAD65. These results indicate that GABAergic synaptic transmission plays a key role in the outer plexiform layer of the vertebrate retina.

c-Fos expression as endogenous marker of lumbosacral spinal neuron activity in response to vaginocervical-stimulation.

The focus of this paper is to describe a method for the simultaneous stimulation of the vagina and uterine cervix and recording of vaginal contractions in the female rat. The influence of the estrous cycle on vaginocervical sensitivity was also investigated. The use of a latex balloon, inflated with water via a syringe and connected to a pressure transducer allowed us to record vaginal contractions, the intensity of which is an index of vaginal sensitivity, and to stimulate those spinal neurons involved in the reflex arc; at the end of the stimulation the deflated balloon was used as a probe to perform a vaginal smear in order to determine the stage of the estrous cycle at the moment of the experiment. Activated neurons were identified by Fos-immunocytochemistry. Light microscope counting of Fos-immunoreactive neurons at different stages of the estrous cycle permitted us to quantify the response to vaginocervical stimulation and to demonstrate that vaginocervical sensitivity changes significantly throughout the estrous cycle. This finding confirms the important role of sex hormones in the modulation and control of the sensitivity of the vagina and cervix, a part of the female genital tract which is implicated in a variety of neuroendocrine, behavioral and neural changes.

Distribution of delta sleep-inducing peptide in the newborn and infant human hypothalamus: an immunohistochemical study.

The distribution of delta sleep-inducing peptide immunoreactive cell bodies, fibers, and terminal-like structures was investigated in the normal human hypothalamus during the first postnatal year, using immunohistofluorescence and peroxidase anti-peroxidase techniques. Immunolabeled perikarya were relatively few and were mostly scattered through the anterior (preoptic) and mediobasal regions (infundibular nucleus) of the hypothalamus. DSIP-immunoreactive fibers and terminal-like fibers were observed throughout the entire rostrocaudal extent of the hypothalamus. They exhibit high densities in the preoptic region, the organum vasculosum of lamina terminalis, infundibular nucleus and median eminence. Moderate to low densities of DSIP-immunoreactive fibers were observed in the other hypothalamic structures, located in the anterior and mediobasal regions of hypothalamus, such as periventricular, paraventricular, suprachiasmatic, ventromedial, dorsomedial and parafornical nuclei. In the present study, the analysis of the immunohistochemical pattern of DSIP-immunoreactive neuronal elements in the human infant hypothalamus during the first postnatal year provided evidence of the presence of several differences. We have found qualitative age-related changes in the density of DSIP immunoreactivity in several hypothalamic structures such as the anterior region and the median eminence.

Immunohistochemical distribution of DSIP immunoreactivity in the human hypothalamus during the first postnatal year. A preliminary report.

The distribution of DSIP-IR cell bodies and fibers was investigated in the normal human hypothalamus during the first postnatal year using the indirect immunofluorescence technique. The analysis of the immunohistochemical patterns obtained in the seven cases analyzed showed regional differences in the localization of cell bodies and fibers. Immunoreactive perikarya were relatively few, and were mostly scattered throughout the anterior and the mediobasal hypothalamus. DSIP-IR fibers and terminal-like structures were observed throughout the rostro-caudal extent of the hypothalamic region. In the present study, we noticed qualitative changes in the density of DSIP immunoreactivity in several hypothalamic structures such as the preoptic area and the median eminence with respect to age. These postnatal differences observed for DSIP could be related to neuronal maturation processes occurring at this period in the central nervous system as well as other physiological processes controlling the evolution of DSIP concentrations. These data are compatible with the proposed role of the neuropeptide in the regulation of many postnatal physiological functions.

Regional distribution of benzodiazepine binding sites in the human newborn and infant hypothalamus. A quantitative autoradiographic study.

Using in vitro quantitative autoradiography and [3H]flunitrazepam we examined the rostrocaudal distribution of benzodiazepine binding sites in the human neonate/infant hypothalamus. The autoradiographic analysis shows the presence of a heterogeneous distribution throughout the rostrocaudal extent of this brain structure. High [3H]flunitrazepam binding corresponds primarily to the diagonal band of Broca and the preoptic region. The labelling in the preoptic region showed a rostrocaudal increase, contrasting in that with the other hypothalamic structures. Intermediate densities were present in the septohypothalamic, suprachiasmatic, periventricular and paraventricular nuclei as well as in the mammillary complex. Low binding was observed in the other hypothalamic structures. The benzodiazepine binding sites analyzed belong mostly to type II receptors. In an attempt to unravel possible differences related to age, we compared the autoradiographic distribution in three postnatal age ranges. The topographical distribution of these binding sites was almost identical in each period analyzed. We found, however, that benzodiazepine binding is generally low in the neonatal period and a tendency in increasing densities is observed during development. Taken together, these results provide evidence for a large distribution of benzodiazepine binding sites in neonate/infant hypothalamus, suggesting their implication in the development of this brain structure and the maintenance of its various functions.

The distribution of NPY-like immunoreactivity in the chameleon brain.

The distribution of neuropeptide Y (NPY) immunoreactivity was studied in the brain of the chameleon. Cell bodies and fibers displaying NPY-like immunoreactivity were widely dispersed throughout the brain and at the highest density in the telencephalon and diencephalon. Immunolabeled cell bodies were numerous in the medial and dorsomedial cortex and in the dorsal ventricular ridge, while the striatum and basal telencephalon only contained sparsely scattered NPY-positive somata. Immunopositive neurons were densely distributed in the dorsal thalamus (particularly in the perirotundal belt), the area triangularis, the nucleus geniculatus lateralis pars dorsalis, the periventricular hypothalamus and the medial eminence. In the pretectum, NPY-immunoreactive cell bodies were limited to the nucleus posterodorsalis, while in the mesencephalon immunolabeled somata were found in the stratum album centrale of the optic tectum and in the substantia nigra. Immunopositive fibers and terminals were particularly dense in the dorsomedial cortex, the periventricular hypothalamus, the nuclei accumbens, suprachiasmaticus and griseus tectalis, in the substantia nigra and in the torus semicircularis. These findings show that the NPY system in the chameleon has the same basic organization as in other vertebrate species, and indicate that this peptide could be also implicated in the regulation of several aspects of cerebral functions. In addition, and of particular interest, is the observation of numerous NPY-immunoreactive neurons and fibers in several visual nuclei, suggesting an important involvement of this substance in the visual function.