Commissural NTS contributes to pressor responses to glutamate injected into the medial NTS of awake rats

In the present study we investigated whether interruption of the chemoreceptor reflex by an electrolytic lesion of the commissural subnucleus of the nucleus tractus solitarii (commNTS) influenced presser and bradycardic responses induced by microinjection of L-glutamate (L-Glu) into the medial NTS (mNTS) of conscious rats. Seven days after sham lesions, seven rats demonstrated significant presser [change in mean arterial pressure (MAP) = +33 +/- 3 mmHg] and bradycardic [change in heart rate (HR) = -74 +/- 8 beats/min (bpm)] responses to chemoreceptor reflex activation by intravenous injection of KCN. Likewise, L-Glu (1 nmol in 100 nl) injected into the mNTS in sham rats induced presser (+29 +/- 2 mmHg) and bradycardic responses (-90 +/- 8 bpm). However, in 11 rats with lesions in commNTS, presser and bradycardic chemoreceptor reflex responses were abolished, and injection of L-Glu into the mNTS decreased MAP (-14 +/- 6 mmHg) and HR (-59 +/- 16 bpm) as is reported in anesthetized control rats. We conclude that presser responses induced by L-Glu microinjected into the baroreceptor reflex region of mNTS in conscious rats depend on the integrity of the commNTS, which plays an important role in central chemoreceptor reflex pathways.

Anxiolytic-like effects produced by bilateral lesion of the periaqueductal gray in mice: Influence of concurrent nociceptive stimulation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparative larval morphology of eight species of Hypsiboas Wagler (Amphibia, Anura, Hylidae) from Argentina and Uruguay, with a review of the larvae of this genus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Regression of the lateral oviducts during the larval-adult transformation of the reproductive system of Melipona quadrifasciata and Frieseomelitta varia

Toward the end of the larval phase (pre-pupa), the reproductive systems of Melipona quadrifasciata and Frieseomelitta varia workers are anatomically similar. Scanning electron microscopy showed that during this developmental phase the right and left ovaries are fused and form a heart-shaped structure located above the midgut. Each ovary is connected to the genital chamber by a long and slender lateral oviduct. During pupal development, the lateral oviducts of workers from both species become extremely reduced due to a drastic process of cell death, as shown by transmission electron microscopy. During the lateral oviduct shortening, their simple columnar epithelial cells show some signs of apoptosis in addition to necrosis. Cell death was characterized by cytoplasmic vesiculation, peculiar accumulation of glycogen, and dilation of cytoplasmic organelles such as mitochondria and rough endoplasmic reticulum. The nuclei, at first irregularly contoured, became swollen, with chromatin flocculation and various areas of condensed chromatin next to the nuclear envelope. At the end of the pupal phase, deep recesses marked the nuclei. At emergence, worker and queen reproductive systems showed marked differences, although reduction in the lateral oviducts was an event occurring in both castes. However, in queens the ovarioles increased in length and the spermatheca was larger than that of workers. At the external anatomical level, the reproductive system of workers and queens could be distinguished in the white- and pink-eyed pupal phase. The metamorphic function of the death of lateral oviduct cells, with consequent oviduct shortening, is discussed in terms of the anatomical reorganization of the reproductive system and of the ventrolateral positioning of adult worker bee ovaries. (C) 2000 Wiley-Liss, Inc.

Haemodynamic effects of hypothalamic disconnection in anaesthetized rats

The aim of the present study was to analyse the haemodynamic effects induced by the hypothalamic disconnection (HD) caudal or rostral to the paraventricular nucleus of the hypothalamus (PVN). Mean arterial pressure (MAP), hindlimb, renal and mesenteric blood flow and vascular conductance (HVC, RVC and MVC, respectively) were measured in urethane (1.2 g/kg, i.v.) anesthetized rats for 60 min after disconnection. HD caudal to the PVN was performed with a double-edged microknife of bayonet shape (R=1 mm, H=2 mm) stereotaxically placed, lowered 2.8 mm caudal to the bregma along the midline. The cut was achieved by rotating the microknife 90° right and 90° left. HD rostral to the PVN was performed with the knife placed 0.8 mm caudal to the bregma. Thirty minutes after the hypothalamic disconnection caudal (HD-C), a decrease in MAP was observed (-14±3 mm Hg), reaching a 60-min decrease of 30±3 mm Hg. Hindlimb conductance increased 10 min after HD (156±14%) and remained elevated throughout the experimental period. On the contrary, we observed a transitory renal vasoconstriction (82±9%, ≤20 min) and a late mesenteric vasodilation, starting at 30 min (108±4%) and reaching 138±6% at 60 min. In rats with HD rostral to the PVN, we only observed minor changes in the cardiovascular parameters. In the MAP, there was a slight decrease 60 min after the hypothalamic disconnection rostral (HD-R) (-9±4 mm Hg). There were no significant changes in HVC. RVC and MVC were increased 60 min after the HD-R (116±12% and 124±11%, respectively). These results suggest that vasodilation in the hindlimb and in the mesenteric bed could contribute to the observed decrease in MAP in HD caudal to PVN rats. © 2002 Elsevier Science B.V. All rights reserved.

Topografia do cone medular da paca (Agouti paca, Linnaeus - 1766)

We object in this work to determine the skeleton sintopy of the medular cone termination of the paca relating to the lumbar and sacral vertebrae, thus aiming at establishing morphometric and topographical parameters of the medular cone in this specie. We accomplished the dissection through skin incision, subcutaneous divulsion and dissection of the vertebral column dorsal region musculature, sectioning and removing the vertebrae arcs for better visualization of the spinal medulla. After the individualization of the medular cone, we registered the anatomical aspects of interest, emphasizing the basis and its apex in relation to the vertebrae, following the measuring of the region using a caliper rule; photographs and schematic drawing were made to register the findings of studied specimens.

Ramificação e distribuição dos nervos frênicos no músculo diafragma do gato doméstico

The ramification and the distribution of the phrenic nerves right and left had been studied in 30 muscles diaphragms of unknown breed adult domestic cats, 7 males and 23 females, and were fixed in 10% buffered formalin solution. After fixation and dissection, it was observed that the phrenic nerves ramified for the respective carnous parts of the muscle diaphragm, pars lumbalis, costalis and sternalis, and had finished in higher frequency in dorsolateral trunk and ventral branch (63.33%). We observed the following arrangements: dorsal, ventral and lateral branches (25.0%); dorsal branch and ventrolateral trunk (6.66%); dorsolateral and ventrolateral trunks (3.33%); dorsolateral trunk, lateral and ventral branches (1.66%). The phrenic nerves had distributed symmetrically in 11 samples (36.66%), only showing the termination in dorsolateral trunk and ventral branch. The dorsal branches supplied pars lumbalis (73.33% to right and 56.66% to the left) and pars costalis (13.33% to right and 10.0% to the left). The right dorsal branch supplied the crus mediale dexter of the right pillar (100.0%) and the left dorsal branch supplied the crus mediale sinister of the right pillar and the left pillar (100.0%). The lateral branches supply pars lumbalis (23.33% to right and 33.33% to the left), pars costalis (96.66% to right and 100.0% to the left) and pars sternalis (3.33% only to the right). The ventral branches supplied the ventral region of pars costalis (46.66 % to right and 43.33% to the left) and pars sternalis (96.66% to right and 100.0% to the left). Four female animals (13.33%) had shown fibers crossing proceeding from the left ventral branch for right antimere had been that in one of these samples (3.33%) occurred connection between the left ventral branch and the right.

Localization of myosin-Va in subpopulations of cells in rat endocrine organs

Myosin-Va is a Ca 2+/calmodulin-regulated unconventional myosin involved in the transport of vesicles, membranous organelles, and macromolecular complexes composed of proteins and mRNA. The cellular localization of myosin-Va has been described in great detail in several vertebrate cell types, including neurons, melanocytes, lymphocytes, auditory tissues, and a number of cultured cells. Here, we provide an immunohistochemical view of the tissue distribution of myosin-Va in the major endocrine organs. Myosin-Va is highly expressed in the pineal and pituitary glands and in specific cell populations of other endocrine glands, especially the parafollicular cells of the thyroid, the principal cells of the parathyroid, the islets of Langerhans of the pancreas, the chromaffin cells of the adrenal medulla, and a subpopulation of interstitial testicular cells. Weak to moderate staining has been detected in steroidogenic cells of the adrenal cortex, ovary, and Leydig cells. Myosin-Va has also been localized to non-endocrine cells, such as the germ cells of the seminiferous epithelium and maturing oocytes and in the intercalated ducts of the exocrine pancreas. These data provide the first systematic description of myosin-Va localization in the major endocrine organs of rat. © 2008 Springer-Verlag.

Osteologia craniana de Nyctibiidae (Aves, Caprimulgiformes)

The Potoos form an exclusively neotropical family of nocturnal birds distributed throughout Central and South America, except Chile, and reaching their highest diversity in the Amazon region. The seven currently recognized species are certainly among the most poorly known birds of this region. They are characterized by a distinctive mimicry of vegetal trunks, where they remain almost motionless during daytime. For this reason, their nocturnal and cryptic habits make them exceedingly difficult to study. Published accounts on behavior and natural history of the family are scarce and contributions regarding its anatomy are rare. Here we sample six of the seven currently recognized species of Nyctibiidae, including Nyctibius grandis, N. aethereus, N. griseus, N. jamaicensis, N. leucopterus and N. bracteatus, in order to conduct a detailed and illustrated description of the skull and jaw osteology. High interspecific variation in skull osteology was observed in the family. Species of this family possess a highly modified skull, adapted to their life habits, which shelters their well developed eyes and permits a large mouth opening. The bones that form the palate structure exhibit a dorsoventral flattening, particularly in the pterigoid and parasphenoid bones, with the palatine bone being a broadly developed, wing-shaped structure. In the maxilar region, near the jugal arch, there is a tooth-like projection, unique among birds, which may assist in the retention of prey upon capture. The vomer bone is highly variable within the family, showing varying numbers of rostral projections amongst species. The broad occipital region exhibits large spacing between the quadrate bones, which are vertically disposed and possess a reduced processus orbitalis. The mandible, which is flexible and elastic, has an extremely short symphyseal region and sindesmotic joints in both mandibular rami. As a family, potoos possess a highly specialized skull which provides insight into the relationship between the form of the structures and the feeding habits of the species. Furthermore, the large interspecific variation in skull morphology emphasizes the needs for taxonomic revision within the family, which at present is lumped into a single genus.

Cellular localization of androgen synthesis in equine granulosa-theca cell tumors: Immunohistochemical expression of 17α-hydroxylase/17,20-lyase cytochrome P450

Elevated blood testosterone concentrations, often accompanied by male-typical behaviors, is a common signalment of mares with granulosa-theca cell tumors (GCTCs), but no definitive information exists regarding the cellular differentiation of tumors associated with androgen secretion. This study was conducted to localize and thereby define the cellular expression of 17α-hydroxylase/17,20-lyase cytochrome P450 (P450c17), the enzyme most directly responsible for androgen synthesis, in 30 GTCTs and control tissues (gonads and adrenal glands) using immuno-histochemistry (IHC). Immuno-reactivity for P450c17 was evident in approximately half of 30 specimens examined, was most consistent in the interstitial cells surrounding existing or developing cysts, and was less intense in cells within cysts in the smaller proportion of specimens where this was observed. In control tissues, the expression of P450c17 was localized primarily in theca interna of normal ovarian follicles, in theca-lutein cells of some corpora lutea, but not in granulosa-lutein cells. Testicular interstitial cells and islands of adreno-cortical cells located in the adrenal medulla of the adrenal cortex further established the specificity of the antisera used. These data provided the first substantive evidence that polyhedral cells identified previously in GTCTs by histopathology have the potential to synthesize and secrete androgens, similar to theca interna and theca lutein cells in normal equine ovaries. © 2010 Elsevier Inc.

Cranial osteology of Picini (Aves: Piciformes: Picidae)

The Picini is composed of 26 species of woodpeckers from the old world that are grouped into seven genera. Given the absence of detailed studies on the cranial osteology of the Picini, the purpose of this study is to describe the cranial osteology of 14 species of Picini from six genera and to compare these species with each other, with other species of woodpeckers and with other bird groups. The results of the analysis of the bone structures of the skull of the Picini indicate that there are seven outstanding characteristic of bones involved in the functional mechanistics of the jaw apparatus. In the ossa cranii, these include the frontal overhang, the postorbital process, the extension of the parietal versus the frontal region and the temporal fossa. In the ossa faciei, these include the rostral expansion of the pterygoid, the ventral palatine fossa and the orbital process of the quadrate bone. For all of the structures associated with the cranial osteology of the investigated species, there is a clear distinction between the species of the genus Picus and the other species studied. Blythipicus rubiginosus, Chrysocolaptes lucidus, Reinwardtipicus validus, Gecinulus viridis and the species of the genus Dinopium exhibit additional particularities. © 2012 The Royal Swedish Academy of Sciences.

Hisonotus bocaiuva, a new species from the rio São Francisco basin, Brazil (Teleostei: Loricariidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Serotonergic neurons in the nucleus raphé obscurus are not involved in the ventilatory and thermoregulatory responses to hypoxia in adult rats

The medullary raphé is an important component of the central respiratory network, playing a key role in CO2 central chemoreception. However, its participation in hypoxic ventilatory responses is less understood. In the present study, we assessed the role of nucleus raphé obscurus (ROb), and specifically 5-HT neurons confined in the ROb, on ventilatory and thermoregulatory responses to hypoxia. Chemical lesions of the ROb were performed using either ibotenic acid (non-specific lesion; control animals received PBS) or anti-SERT-SAP (5-HT specific lesion; control animals received IgG-SAP). Ventilation (VE; whole body plethysmograph) and body temperature (Tb; data loggers) were measured during normoxia (21% O2, N2 balance) and hypoxia exposure (7% O2, N2 balance, 1h) in conscious adult rats. Ibotenic acid or anti-SERT-SAP-induced lesions did not affect baseline values of VE and Tb. Similarly, both lesion procedures did not alter the ventilatory or thermoregulatory responses to hypoxia. Although evidence in the literature suggests a role of the rostral medullary raphé in hypoxic ventilatory responses, under the present experimental conditions our data indicate that caudal medullary raphé (ROb) and its 5-HT neurons neither participate in the tonic maintenance of breathing nor in the ventilatory and thermal responses to hypoxia. © 2013 Elsevier B.V.

Variabilidade da frequência cardíaca como ferramenta de análise da função autonômica de tabagistas: revisão de literatura e estudo do plot de Poincaré

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)