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 CCNWXJ40-4^T , 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 CCNWXJ40-4^T ; 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 Per2^Luc 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.

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.

This paper presents a methodology to design a versatile, unique multi-well plate for high-throughput characterisation of heterogeneous catalyst by 4 different techniques (IR, Raman, XRF and XRD).

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.

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.

A quantitative ultrastructural study of the optic nerve of the chameleon

The optic nerve of adult chameleons was investigated with an electron microscope. The total number of retinal ganglion cell axons, the proportion of myelinated axons, the frequency distributions of myelinated and unmyelinated axon diameters were estimated, together with the volume occupied by glial processes. These were distinguished from unmyelinated axons using an antibody directed against glial fibrillary acidic protein, in a post-embedding procedure. The total number of fibers was estimated to be 405,235 +/- 60,000 axons. The proportion of myelinated fibers varied with position between the eyeball and the chiasma; being 22-27% close to the eyeball, rising to 42-47% halfway along the optic nerve and to 56-62% close to the chiasma. Myelinated and unmyelinated fiber diameter distributions were unimodal and positively skewed, with modes of 0.7 microm and 0.2 microm, respectively. There was a significant regional variation in the size of optic nerve axons. Large myelinated axons were observed in the dorsal and ventral periphery, whereas smaller myelinated fibers and a high proportion of unmyelinated fibers were found in the center of the nerve.

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.

Influence of estrous cycle on vaginocervical sensitivity: a fos-immunohistochemical study of lumbosacral spinal cord

Expression of c-fos in L(5)-S(1) spinal segments in response to mechanical vaginocervical stimulation was investigated in both cycling and ovariectomized females. The aim of this paper was to verify the influence of estrous cycle on females genital tract sensitivity using immunodetection of a neural activity endogenous marker. The results indicate that lumbosacral spinal Fos-labeling was highly increased in vaginocervical stimulated rats relative to control, and labeled neurons were present more intensively in the dorsal horn in comparison to other spinal areas. Significant differences in Fos-labeling were observed according to the estrous cycle stage at which the stimulation was applied. In estrous females, the response was greater than that obtained at diestrous and much greater than the response of proestrous females. The spinal Fos-labeling of ovariectomized females is equivalent to that of diestrous females. These results give evidence that the vaginocervical induced expression of c-fos is modulated by cyclic changes in circulating sex hormones, whereas results observed in ovariectomized females indicate the likely involvement of other mechanisms independent of ovarian hormones.

Benzodiazepine binding sites in the human hypothalamus. Autoradiographic study

Using in vitro labelling and autoradiographic techniques, we have analyzed the fine and the detailed distribution of benzodiazepine binding sites in the post-mortem human hypothalamus. Binding sites were labelled in mounted tissue sections from adult brains, using the selective high affinity ligand [3H]-Flunitrazepam. A heterogeneous distribution of benzodiazepine binding sites was found throughout the rostrocaudal extent of human hypothalamus. The autoradiographic labelling was shown in the three hypothalamic parts, i.e., anterior, mediobasal and posterior levels. At the anterior level, the highest densities were present in the diagonal band of Broca, the preoptic area (medial and lateral parts) and the septohypothalamic nucleus. At the mediobasal hypothalamic level, the highest densities were mainly localized in the ventromedial nucleus, whereas the other structures were moderately labelled with [3H]-Flunitrazepam. The mammillary complex as well as the posterior hypothalamic area represented the most heavily labelled structures in the posterior hypothalamus. The results obtained in this study, indicate the presence of a large and heterogeneous distribution of benzodiazepine binding sites in human adult hypothalamus. This could support their implication in the control of distinct neural functions (like neuroendocrine role).

Localization of motoneurons innervating the extraocular muscles in the chameleon (Chamaeleo chameleon)

The topography and localization of motoneurons innervating the six extraocular muscles in the chameleon (Chamaeleo chameleon) was studied following HRP injection in each of these individual muscles. Four muscles were innervated ipsilaterally: medial rectus, inferior rectus, inferior oblique and lateral rectus. The medial rectus muscle was innervated by the dorsomedial part of the oculomotor nucleus. The innervation to the inferior rectus muscle arose from the lateral part of the intermediate oculomotor subnucleus, which extended to the lateral part of the dorsal subdivision. The lateral rectus muscle was innervated by the abducens nucleus, which was composed by two subgroups of labeled cells, respectively observed in the principal and accessory abducens subnuclei, whereas efferents to the inferior oblique muscle originated from both the ventral and intermediate oculomotor subnuclei. The contralateral pattern consisted of motoneurons innervating the superior rectus and the superior oblique that were located respectively in the caudal portion of the ventral oculomotor nucleus and in the trochlear nucleus. These results confirmed data reported in most vertebrate species, and were discussed from a comparative and functional point of view.

An immunohistochemical study of putative neuromodulators and transmitters in the centrifugal visual system of the quail (Coturnix japonica)

The aim of the present study was to analyze the neurochemical properties of the centrifugal visual system (CVS) of the quail using an immunohistochemical approach by testing 16 neuropeptides (angiotensin: ANG, bradykinin: BK, cholecystokinin, dynorphin, L and M-enkephalin, beta-endorphin: beta-END, galanin, alpha-neoendorphin, neurokinin A, neuropeptide Y (NPY), ocytocin, somatostatin, substance P, vasopressin, vasoactive intestinal polypeptide) and three neurotransmitters or their synthetic enzymes (choline acetyltransferase: ChAT, tyrosine hydroxylase: TH, serotonin: 5-HT and nitric oxide synthase: NOS, including the histochemical nicotinamide adenine dinucleotide phosphate diaphorase technique). For each substance, the somatic and afferent fiber and terminal labeling was analyzed within the nucleus isthmo-opticus (NIO) and the ectopic area (EA) and compared with that of retinopetal cell bodies labeled retrogradely with RITC following its intraocular injection (double-labeling procedure). The results showed that none of the centrifugal neurons were reactive to any of the substances tested. In contrast, all with the exception of ANG, BK and beta-END, labeled fibers and terminals within the EA and only four (ChAT, 5-HT, NPY and NOS) within the NIO. Possible sources of these immunoreactive fibers terminating in the NIO and EA were investigated by mapping the somatic immunolabeling of the different substances within brainstem regions previously shown by Miceli and other authors to project upon the centrifugal neurons. The data suggests that, besides the rapid retino-tecto-NIO-retinal loop, which facilitates the transfer of meaningful or more relevant information within particular portions of the visual field, the multiple afferent input which stems from various brainstem regions utilizes a wide range of neuroactive substances. Some of these afferent projections upon the centrifugal neurons appear to belong to nonspecific systems which might play a role in modulating the excitability of centrifugal neurons as a function of arousal.

The retinopetal visual system in the chameleon (Chameleo chameleon)

Intraocular injections of rhodamine and horseradish peroxidase in chameleon, labelled retrogradely neurons in the ventromedial tegmental region of the mesencephalon and the ventrolateral thalamus of the diencephalon. In both areas, staining was observed contralaterally to the injected eye. Labelling was occasionally observed in some rhombencephalic motor nuclei. These results indicate that chameleons, unlike other reptilian species, have two retinopetal nuclei.

Evidence for co-existence of CCK-8 and GnRH in neurons of the mesencephalic tegmentum in the chameleon

A double-label immunofluorescence technique was used to demonstrate the co-localization of cholecystokinin-8 (CCK-8) and gonadotrophin-releasing hormone (GnRH) in individual neurons and processes of the chameleon brain. Co-localization was limited to a small population of cells in the dorsomedial tegmentum; in other regions of the brain, neurons were observed to be either CCK-8-immunopositive or GnRH-immunopositive but never both. However, double-labeled fibers and terminals were found to be distributed at a low density throughout the thalamus, the medial hypothalamus, the tegmentum and the spinal cord. These data provide the first indication for the co-localization of CCK-8 and GnRH, whose functional significance remains to be established. ON

Quantitative and topographical study of retinal ganglion cells in the chameleon (Chameleo chameleon)

Chameleons display a number of well-described physiological peculiarities of their visual system, but there is no information on the topography of the retinal ganglion cell layer. In the present study, ganglion cell density of the chameleon retina was constructed from whole mounts of the retina stained with cresyl violet. For the identification of ganglion cells, these latter cells were labelled retrogradely with horseradish peroxidase applied to the optic nerve. Using this criterion, the proportion of ganglion cells was estimated to represent 80% of retinal cells, while glial cells and amacrine cells represented 14 and 6%, respectively, of the total cell population of the retina. As for the main features of the retinal map, first, ganglion cells were distributed inhomogeneously within the ganglion cell layer, and revealed the existence of a putative area centralis. Second, a horizontal visual streak, which showed two peak density areas, was identified. These features point out the degree of specialisation of the chameleon retina and the complexity of its visual system.

Characteristics of cervico-ocular responses in the chameleon

The cervico-ocular reflex (COR) was investigated in the chameleon. Two kinds of responses were observed by oscillating the body (sine-wave stimuli) in the fixed-head animal: a "smooth response" of very low gain (around 0.08) and a saccadic response composed of 1-12 saccades per cycle of stimulation (depending on the stimulation frequency). Both responses were elicited in the compensatory direction (same direction as the stimulation) and exhibited a frequency dependence with low-pass properties. The saccadic response was especially developed and displayed a higher gain (up to 0.4) than the smooth response. In darkness, the saccades were triggered near the zero point (head-body alignment), whereas in the presence of a fixed visual surround they were elicited more regularly throughout the stimulation cycle. The amplitude of saccades was increased in the light. Consequently, the gain and the phase lag of the saccadic response were enhanced by the visual input. No visuo-cervical interaction was observed for the smooth response. Oscillating the body at a constant velocity (seesaw or ramp stimuli) revealed a frequency effect on the number of saccades (during a cycle of stimulation), but not on the gain of the response. Increasing the amplitude of oscillations augmented only very slightly the amplitude of saccades and consequently decreased the gain. Hence, the best working range of the saccadic response corresponds to body or head movements of low amplitude (up to +/- 20 deg) and low frequency (up to 0.25 Hz), and is improved by a visual input. These properties are discussed on a comparative point of view. It is proposed that, in chameleons, the saccadic response could contribute to gaze stabilization and add to the vestibulo-ocular and the optokinetic responses.

Cholecystokinin-like systems in the chameleon brain

Immunohistochemical techniques were used to determine the distribution of cholecystokinin-8 (CCK8) immunoreactivity in the brain of the chameleon. In the telencephalon, CCK8-immunopositive somata were sparse and observed principally in the olfactory tubercle at the ventromedial edge of the rostral telencephalon and in the medial septum. Immunopositive fibers were observed mainly in the medial septal region and the ventral telencephalon. In the diencephalon, numerous CCK8-reactive fibers were densely concentrated in the periventricular region, the dorsolateral hypothalamus and the external zone of the median eminence. In the thalamus, labelled fibers were restricted to the peri-rotundal nuclei and the lateral part of the habenula. Immunoreactive cell bodies were observed in the medial part of the dorsal lateral geniculate nucleus, in the periventricular, ventral and lateral regions of the hypothalamus. In the mesencephalon, the densest accumulations of immunopositive fibers were observed in the area pretectalis, the periventricular gray matter, the medial tegmentum and the isthmus. Labelled neurons were observed in the deep, and occasionally intermediate, tectal layers and in the laminar nucleus of the torus semicircularis. In the rhombencephalon, labelled fibers were observed at the highest density in the central gray matter and the locus coeruleus; labelled somata were observed only in the nucleus of the tractus solitarius.

Catecholamine-, indoleamine-, and GABA-containing cells in the chameleon retina

Neurons containing catecholamine, indoleamine, and gamma-aminobutyric acid (GABA) were identified by immunohistochemistry in the chameleon retina. Tyrosine hydroxylase (TH) and serotonin (5HT) were observed mostly in two subtypes of orthotopic amacrine cells differing in their soma size and process distribution within the IPL. Some labelled cells were displaced either to the IPL (5HT) or the GCL (TH and 5HT). A multiplicity of retinal cell types contained GABA including cones, horizontal, amacrine, and ganglion cells. Our results confirmed those obtained in the retinas of other lizards except for the presence of interstitial and displaced amacrine cells containing TH or 5HT of which this is the first report.

Distribution of substance P-like immunoreactivity in the chameleon brain

The distribution of substance P-like immunoreactivity in the chameleon brain and spinal cord was studied with immunohistochemical methods using polyclonal antibodies against substance P. In the telencephalon, immunoreactive cell bodies and fibers were located primarily in the striatum and in the globus pallidus. In addition, few substance P-like fibers were observed in the cortical areas, in the septum, and in the amygdala. In the diencephalon, a high density of immunostained neurons and fibers were seen in the periventricular and ventrolateral hypothalamus. Another group of cell bodies was located in the optic tectum and particularly in the stratum griseum central. A large number of immunoreactive fibers were also detected in the thalamic nuclei and in the median eminence. In the mesencephalon, few immunoreactive neurons were observed in the ventral tegmental area, in the substantia nigra, and in the nucleus reticularis isthmi. These latter nuclei, the periventricular area, the posterior commissure, the nucleus lentiformis mesencephali, the oculomotor nucleus, and the raphe nuclei contained a dense plexus of substance P immunoreactive fibers. No immunoreactive cell bodies were observed in raphe nuclei. In the spinal cord, no substance P-like immunoreactive neurons were observed, but a large number of substance P immunostained fibers were seen in the dorsal and lateral part of the dorsal horn and surrounding the dorsal parts of the central canal. The results of the present study are discussed with respect to those obtained in other species of reptiles, the main differences concerning the lateral septum, the habenula, the area of the paraventricular organ, and the raphe nuclei.

An experimental re-evaluation of the primary visual system of the European chameleon, Chamaeleo chameleon

The retinofugal projections of the chameleon were investigated by means of autoradiography, horseradish peroxidase and fluorescent techniques after intraocular injection of tracers. An ipsilateral contingent of visual fibers and projections is absent. The retinal fibers decussate completely in alternating fascicles at the optic chiasma and course to terminate in two hypothalamic nuclei (nucleus suprachiasmaticus and nucleus opticus periventricularis hypothalami posterior), six thalamic nuclei (nucleus ovalis, nucleus geniculatus lateralis dorsalis partes lateralis and medialis, nucleus geniculatus lateralis ventralis, lateral part of nucleus dorsolateralis anterior, and nucleus ventrobasalis), four pretectal nuclei (nucleus griseus tectalis, nucleus lentiformis mesencephali, nucleus geniculatus pretectalis and nucleus posterodorsalis), the optic tectum (stratum griseum et fibrosum superficiale) and the tegmental nucleus opticus tegmenti. Our findings are, in general, compatible with previous descriptions of the primary visual system in other species of lizards. However, they indicate three features particular to chameleons: first, the total absence of an ipsilateral retinofugal projection; second, the existence of an additional hypothalamic visual center located in the posterior mediodorsal hypothalamus; and third, the large size of nucleus opticus tegmenti. These features are discussed in terms of the taxonomic position of chameleons with respect to other lizards.

Sensorimotor cortex projections to the ventrolateral and the dorsomedial medulla oblongata in the rat

After small pressure injections of Fluorogold (FG), and Dextran-tetramethylrodamine (DR) into the dorsal motor nucleus of the vagus/nucleus of the solitary tract (DMV/NTS) and the rostral ventrolateral medulla (RVLM), respectively, retrograde FG-labelled cells were found mainly in the sensorimotor cortex; retrograde DR-labelled cells were located in the same cortical areas and in the prefrontal cortex. Double-labelled cells were also found in the sensorimotor cortical areas. These results provide evidence of direct projections from the sensorimotor cortex to the DMV/NTS and RVLM and suggest that somatic cortical areas directly control cardiovascular output during sensory and somatic processes.

Visual and vestibular reflexes that stabilize gaze in the chameleon

Spontaneous eye movements as well as visual, vestibular, and proprioceptive cervical reflexes which contribute to gaze stabilization were investigated in the chameleon using the magnetic search-coil technique. The oculomotor range of each eye was very large (180 deg horizontally x 80 deg vertically). Spontaneous ocular saccades were independent in the two eyes and could have very large amplitudes. The fast phases of nystagmus during the stabilization reflexes were also independent in the eyes. In the head-restrained condition, optokinetic nystagmus (OKN) had a low gain in both horizontal and vertical planes (0.35 at 5 deg/s) and showed little binocular interaction. The vestibulo-ocular reflex (VOR) exhibited a low gain (0.2-0.3 from 0.05-1 Hz) and a high-phase lead at low frequency (140 deg at 0.05 Hz). Rotation of the animal in the presence of a visible surround increased the overall gain of gaze stabilization to 0.4-0.5 (P < 0.01) and considerably reduced the phase lead (38 deg at 0.05 Hz). In the head-free condition, head and eye reflexes were active simultaneously during both optokinetic and vestibular stimulation, but nystagmic head movements appeared only occasionally with a rather loose eye-head coordination. During optokinetic stimulation, eye movements contributed more than head movements to gaze stabilization, whereas, during vestibular or visuo-vestibular stimulation, the relative contribution of eye and head responses varied with stimulus frequency. When the head was freed, overall gain for gaze stabilization increased from 0.35 to 0.45 (P < 0.05) for optokinetic stimulation at 5 deg/s and from 0.2-0.3 to 0.4-0.75 (P < 0.001) for vestibular stimulation at 0.05-1 Hz.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of GABA immunoreactive systems in the forebrain and midbrain of the chameleon

An immunocytochemical method, using glutaraldehyde fixation and an antiserum developed against a GABA-glutaraldehyde protein conjugate, permitted direct visualization of GABAergic structures in the brain of a reptile (chameleon). GABA immunoreactive cell bodies and nerve terminals were observed to be evenly distributed throughout the forebrain and midbrain. In the forebrain, GABA-positive perikarya were shown in all cortical areas, the septal area, the striatum, the dorsal ventricular ridge, and in the nucleus accumbens. In the midbrain, the optic tectum contained a dense and laminar distribution of GABA neurons. These neurons were also observed in the lateral geniculate nucleus, nucleus profundus mesencephali, nucleus opticus tegmenti and substantia nigra. Immunoreactive nerve fibers and terminals were observed in the same structures and, additionally, in the tractus septo-hypothalamicus, habenula complex, median eminence, intermediate lobe of the pituitary, basal part of the subcommissural organ, torus semicircularis and nucleus reticularis isthmi. These results provide a framework for a further electron microscopic analysis of the GABAergic innervation of some encephalic areas involved in physiological regulations particular to this species especially the visual system.

Existence of a GnRH immunoreactive nucleus in the dorsal midbrain tegmentum of the chameleon

The GnRH system of the chameleon brain was studied at light microscopic and ultrastructural levels by use of an immunohistochemical technique with antibodies directed against salmon gonadotrophin-releasing hormone. Immunoreactive (IR) perikarya were found in the anterior midbrain tegmentum. At this level numerous IR cell bodies were detected around the fasciculus longitudinalis medialis (FLM). The more rostral neurons were observed dorsal to the FLM and progressively tended to be lateral to it along the midline. More caudally, they were found ventral to the FLM. At the electron microscope level, these cells were seen to contain large granular vesicles and to receive numerous synaptic inputs. A prominent pathway was traced from these cell bodies along the medulla oblongata to the spinal cord. A second IR pathway ascended rostrally to the habenular complex. No IR perikarya were located in the anterior brain including the olfactory bulbs.

Inhibition of antral and pyloric electrical activity by vagal afferent stimulation in the rabbit

The effects of stimulation of cervical vagal afferents on the electromyographic activity (e.m.g.) of the gastric antrum and pylorus have been studied both in conscious and decorticate, curarized rabbits. In the latter group, stimulation at 10-15 Hz (0.3-0.4 mA; 5-7 ms duration) inhibited both the antral and pyloric e.m.g. in 21 rabbits, elicited an excitatory response in two more but produced no change in the remaining 13 animals. The inhibitory response was not affected by guanethidine (1 mg/kg, i.v.), phentolamine (1 mg/kg, i.v.) or propranolol (0.1 mg/kg, i.v.) and persisted in rabbits in which the contralateral cervical vagus and both splanchnic nerves had been cut, the coeliac ganglia and both adrenal glands had been extirpated. It was only abolished by combined section of the spinal cord at the level of C1, C2 and the contralateral vagus in the neck. In conscious rabbits, vagal stimulation at 2-5 Hz (0.4 mA; 0.5-1.0 ms duration) consistently inhibited antral and pyloric e.m.g. This inhibitory response persisted in the presence of phentolamine, propranolol and naloxone (0.25-1.00 mg/kg), and in adrenalectomized rabbits with cut splanchnic nerves and extirpated coeliac ganglia. However, it was completely abolished by section of both vagi above the diaphragm. It is concluded that (1) the vagal afferents responsible for the inhibition of the gastric e.m.g. are already included in the abdominal vagus nerves, (2) this inhibition of gastric e.m.g. is mediated by non-adrenergic fibers, one group of them emerging from the thoracic spinal cord to join the thoracic vagi via the stellate ganglia.