Bases ósseas e musculares dos cortes comerciais do tronco de jacaré-do-Pantanal (Caimanyacare Daudin, 1802)

Resumo: O consumo de carne de jacaré-do-Pantanal tornou-se uma tendência de mercado e uma cadeia produtiva em ascensão no Estado de Mato Grosso, sendo 28,40% da carne comercializada nos últimos quatro anos oriundos do tronco. Estudos evolutivos, morfofisiológicos, ontogenéticos e tecnológicos foram desenvolvidos, mas não há descrição da musculatura e bases ósseas dos cortes comerciais. Objetivou-se descrever os músculos e correspondentes bases ósseas dos cortes filé de lombo, filé mignon e aparas. Na descrição óssea, utilizaram-se seis carcaças desossadas de exemplares juvenis de jacaré-do-Pantanal, além de um exemplar adulto, obtido por doação após óbito, do Zoológico da UFMT. Os ossos foram macerados em água corrente, clareados e descritos. Para a descrição muscular, 24 exemplares juvenis foram abatidos e esfolados, conservados em freezer e descongelados quando utilizados, sem qualquer fixação. Após a evisceração, foram dissecados em ambos os antímeros. Os músculos semiespinhal, longuíssimo e iliocostal, fixados nas vértebras e costelas torácicas, lombares e sacrais, formam o filé de lombo. O corte aparas é constituído pelos músculos grande dorsal, serrátil, peitoral e abdominais (oblíquo externo, oblíquo interno, transverso e reto), cuja base óssea corresponde as costelas torácicas, lombares e sacrais, a gastrália, o esterno e o epipúbis. Por sua vez, o m. puboisquiofemoral interno cranial, localizado na região sublombar e o m. troncocaudal, da superfície ventral da pelve, compreendem o filé mignon.

Descrição anatômica de esqueletos de papagaios do gênero Amazona através da utilização de radiografias

Resumo: O esqueleto de papagaios da espécie Amazona aestiva foi descrito e comparado com representantes de outras espécies do gênero Amazona. Para tanto, foram utilizados 22 exemplares da espécie Amazona aestiva; dois das espécies Amazona vinacea; Amazona rhodocorythae, Amazona farinosa, além de um exemplar das espécies Amazona brasiliensis e Amazona pretrei, doados após morte natural pelo Criadouro Poços de Caldas. Foram realizadas radiografias de corpo inteiro, variando de decúbito lateral direito ou esquerdo, no caso das projeções latero-laterais, e em decúbito dorsal, no caso da projeção ventro-dorsal. Independentemente da espécie, os crânios dos papagaios estudados puderam ser classificados como pró-cinéticos, por apresentarem liberdade de movimentos em sua porção rostral. Na maioria dos casos, a coluna vertebral esteve formada por 12 vértebras cervicais, seis vértebras torácicas livres, sinsacro (formado pela fusão da última vértebra torácica, 7 lombosacrais e uma caudal), cinco vértebras caudais livres e pelo pigóstilo (formado por três vértebras caudais fusionadas) e, apesar de diferenças pontuais, o esqueleto apendicular torácico e pélvico se mostrou muito semelhante ao observado para outros gêneros de aves e, inclusive, não foi possível observar dimorfismo sexual através das características anatômicas dos esqueletos dos papagaios trabalhados.

Morfologia e anatomia da semente de Schinus terebinthifolius Raddi (Anacardiaceae) em desenvolvimento

A semente de Schinus terebinthifolius única por fruto é reniforme, com envoltório membranáceo, liso, de coloração amarelo-clara, com uma mancha marrom escura. É exalbuminosa tendo como reserva nos cotilédones proteínas e lipídeos. O óvulo é anátropo, bitegumentado, crassinucelado com rafe dorsal evidente e inserido em posição apical-lateral no fruto. O concrescimento do tegumento externo com a base do funículo forma um obturador funicular parcialmente tegumentar. A hipóstase tanífera provém dos tecidos calazal e nucelar. A presença de restos do funículo aderidos ao envoltório da semente madura é considerada como um arilo vestigial. O envoltório tem dupla origem, uma parcialmente paquicalazal, que na semente madura se manifesta externamente como uma mancha marrom escura e a outra tegumentar.

Estrutura do pericarpo e da semente de Astronium graveolens Jacq. (Anacardiaceae) com notas taxonômicas

Astronium graveolens é um representante arbóreo da família Anacardiaceae que se distribui desde o México até o centro-sul da América do Sul. O fruto é uma pseudo-sâmara com exocarpo unisseriado, suberificado e aderido ao mesocarpo. O mesocarpo é parenquimático, com grandes canais secretores associados aos feixes vasculares e localizados próximos ao endocarpo. O endocarpo parenquimático é bisseriado, sendo a camada que reveste o lóculo ligeiramente alongada radialmente. O óvulo é anátropo, unitegumentado, crassinucelado, com rafe dorsal evidente e hipóstase tanífera; apresenta obturador placentário e está inserido em posição apical-lateral no fruto. A testa, fortemente adnata ao pericarpo, apresenta as células da epiderme interna pequenas e de conteúdo bastante denso, indicando uma condição endotestal. O envoltório na semente madura é formado por restos da testa, funículo, região rafe-calazal e hipóstase apresentando duas regiões distintas: uma paquicalazal de coloração marrom e outra tegumentar de coloração amarelo-clara. O embrião ocupa posição axial e é do tipo "investing".

Morfologia e anatomia da flor de Pilocarpus pennatifolius Lem. (Rutaceae)

Pilocarpus pennatifolius Lem. (Rutaceae) apresenta flores actinomorfas, diclamídeas, nectaríferas e monoclinas, reunidas em cacho pendente. Apresenta antese basípeta na inflorescência e preferencialmente noturna. A flor possui cinco estames com anteras tetrasporangiadas, cuja parede é constituída de epiderme, endotécio, duas camadas médias e tapete binucleado; o conectivo mostra epiderme estomatífera. O gineceu é unipistilado e composto por cinco carpelos unidos na região basal do ovário e no estilete e estigma. O estilete é curto e sólido e o estigma tem epiderme papilosa. O rudimento seminal (óvulo) é hemítropo, bitegumentado, crassinucelado e provido de hipóstase e possui obturador de origem funicular. O nectário envolve completamente a base do ovário. Cada sépala recebe três traços vasculares e as pétalas e estames apenas um; cada carpelo recebe um feixe vascular dorsal e dois ventrais, que mantêm individualidade em todo seu curso.

Involvement of the hippocampus, amygdala, entorhinal cortex and posterior parietal cortex in memory consolidation

A total of 182 young adult male Wistar rats were bilaterally implanted with cannulae into the CA1 region of the dorsal hippocampus and into the amygdaloid nucleus, the entorhinal cortex, and the posterior parietal cortex. After recovery, the animals were trained in a step-down inhibitory avoidance task. At various times after training (0, 30, 60 or 90 min) the animals received a 0.5-µl microinfusion of vehicle (saline) or 0.5 µg of muscimol dissolved in the vehicle. A retention test was carried out 24 h after training. Retention test performance was hindered by muscimol administered into both the hippocampus and amygdala at 0 but not at 30 min posttraining. The drug was amnestic when given into the entorhinal cortex 30, 60 or 90 min after training, or into the parietal cortex 60 or 90 min after training, but not before. These findings suggest a sequential entry operation, during the posttraining period, of the hippocampus and amygdala, the entorhinal cortex, and the posterior parietal cortex in memory processing

Interrelationship between adipocytes and fibroblasts during acute damage to the subcutaneous adipose tissue of rats: an ultrastructural study

Ultrastructural phenotypic transitional features were noted between adult adipocytes and fibroblasts in the subcutaneous adipose tissue of the dorsal pad of normal adult Wistar rats of both sexes, weighing 180-260 g, after acute injury either by the implantation of small (1.8 x 1 x 0.4 cm) perforated plastic boxes or by local heat application. Soon after the inflicted damage, fat-containing cells presented variable shapes. Early after damage, some of these cells were round, adipocyte-like, with numerous and large cytoplasmic fat droplets. A few days later, fat-containing cells became elongated, with the fat droplets in their cytoplasm becoming smaller and less numerous. The cells also showed a prominent active rough endoplasmic reticulum and newly formed collagenous matrix accumulated in the interstices. Although current views consider adult adipocytes to be terminal cells, the present findings, in their time sequence, strongly suggest the transformation of adipocytes into fibroblasts after acute injury to adipose tissue.

Endogenous vasopressin and the central control of heart rate during dynamic exercise

The present article contains a brief review on the role of vasopressinergic projections to the nucleus tractus solitarii in the genesis of reflex bradycardia and in the modulation of heart rate control during exercise. The effects of vasopressin on exercise tachycardia are discussed on the basis of both the endogenous peptide content changes and the heart rate response changes observed during running in sedentary and trained rats. Dynamic exercise caused a specific vasopressin content increase in dorsal and ventral brainstem areas. In accordance, rats pretreated with the peptide or the V1 blocker into the nucleus tractus solitarii showed a significant potentiation or a marked blunting of the exercise tachycardia, respectively, without any change in the pressure response to exercise. It is proposed that the long-descending vasopressinergic pathway to the nucleus tractus solitarii serves as one link between the two main neural controllers of circulation, i.e., the central command and feedback control mechanisms driven by the peripheral receptors. Therefore, vasopressinergic input could contribute to the adjustment of heart rate response (and cardiac output) to the circulatory demand during exercise.

Involvement of hippocampal NMDA receptors in retention of shuttle avoidance conditioning in rats

The purpose of this research was to evaluate the role of hippocampal N-methyl-D-aspartate (NMDA) receptors in acquisition and consolidation of memory during shuttle avoidance conditioning in rats. Adult male Wistar rats were surgically implanted with cannulae aimed at the CA1 area of the dorsal hippocampus. After recovery from surgery, animals were trained and tested in a shuttle avoidance apparatus (30 trials, 0.5-mA footshock, 24-h training-test interval). Immediately before or immediately after training, animals received a bilateral intrahippocampal 0.5-µl infusion containing 5.0 µg of the NMDA competitive receptor antagonist aminophosphonopentanoic acid (AP5) or vehicle (phosphate-buffered saline, pH 7.4). Infusion duration was 2 min per side. Pre-training infusion of AP5 impaired retention test performance (mean ± SEM number of conditioned responses (CRs) during retention test session was 16.47 ± 1.78 in the vehicle group and 9.93 ± 1.59 in the AP5 group; P<0.05). Post-training infusion of AP5 did not affect retention (mean ± SEM number of conditioned responses during retention test session was 18.46 ± 1.94 in the vehicle group and 20.42 ± 2.38 in the AP5 group; P>0.10). This impairment could not be attributed to an effect on acquisition, motor activity or footshock sensitivity since AP5 affected neither training session performance measured by the number of CRs nor the number of intertrial crossings during the training session. These data suggest that NMDA receptors in the hippocampus are critical for retention of shuttle avoidance conditioning, in agreement with previous evidence showing a role of NMDA receptors in fear memory.

Decreased gastric emptying and gastrointestinal and intestinal transits of liquid after complete spinal cord transection in awake rats

We studied the effect of complete spinal cord transection (SCT) on gastric emptying (GE) and on gastrointestinal (GI) and intestinal transits of liquid in awake rats using the phenol red method. Male Wistar rats (N = 65) weighing 180-200 g were fasted for 24 h and complete SCT was performed between C7 and T1 vertebrae after a careful midline dorsal incision. GE and GI and intestinal transits were measured 15 min, 6 h or 24 h after recovery from anesthesia. A test meal (0.5 mg/ml phenol red in 5% glucose solution) was administered intragastrically (1.5 ml) and the animals were sacrificed by an iv thiopental overdose 10 min later to evaluate GE and GI transit. For intestinal transit measurements, 1 ml of the test meal was administered into the proximal duodenum through a cannula inserted into a gastric fistula. GE was inhibited (P<0.05) by 34.3, 23.4 and 22.7%, respectively, at 15 min, 6 h and 24 h after SCT. GI transit was inhibited (P<0.05) by 42.5, 19.8 and 18.4%, respectively, at 15 min, 6 h and 24 h after SCT. Intestinal transit was also inhibited (P<0.05) by 48.8, 47.2 and 40.1%, respectively, at 15 min, 6 h and 24 h after SCT. Mean arterial pressure was significantly decreased (P<0.05) by 48.5, 46.8 and 41.5%, respectively, at 15 min, 6 h and 24 h after SCT. In summary, our report describes a decreased GE and GI and intestinal transits in awake rats within the first 24 h after high SCT.

Ethological analysis of mother-pup interactions and other behavioral reactions in rats: effects of malnutrition and tactile stimulation of the pups

Mother-pup interaction, as well as other behavioral reactions were studied during the lactation period in 24 litters of Wistar rats and their dams fed either a 16% (control - C; 12 litters) or a 6% (malnourished - M; 12 litters) protein diet. The diets were isocaloric. Throughout lactation there was a 36.4% weight loss of M dams and a 63% body weight deficit in the M pups when compared to control pups. During this period, half of the litters were exposed daily to additional tactile stimulation (CS or MS), while the other half were submitted to normal rearing conditions (CN or MN). The tactile stimulation of pups (handling) consisted of holding the animal in one hand and gently touching the dorsal part of the animal's body with the fingers for 3 min. A special camera and a time-lapse video were used to record litter behavior in their home cages. Starting at 6 p.m. and ending at 6 a.m., on days 3, 6, 12, 15, 18 and 21 of lactation, photos were taken at 4-s intervals. An increase in the frequency (154.88 ± 16.19) and duration (455.86 ± 18.05 min) of suckling was observed throughout the lactation period in all groups compared to birth day (frequency 24.88 ± 2.37 and duration 376.76 ± 21.01 min), but the frequency was higher in the C (84.96 ± 8.52) than in the M group (43.13 ± 4.37); however, the M group (470.2 ± 11.87 min) spent more time suckling as compared with the C group (393.67 ± 13.09 min). The M dams showed a decreased frequency of resting position throughout the lactation period (6.5 ± 2.48) compared to birth day (25.42 ± 7.74). Pups from the C group were more frequently observed separated (73.02 ± 4.38) and interacting (258.99 ± 20.61) more with their mothers than the M pups (separated 66.94 ± 5.5 and interacting 165.72 ± 12.05). Tactile stimulation did not interact with diet condition, showing that the kind of stimulation used in the present study did not lead to recovery from the changes induced by protein malnutrition. The changes in mother-pup interaction produced by protein malnutrition of both may represent retardation in neuromotor development and a higher dependence of the pups on their mothers. These changes may represent an important means of energy saving and heat maintenance in malnourished pups.

Induction of Fos protein immunoreactivity by spinal cord contusion

The objective of the present study was to identify neurons in the central nervous system that respond to spinal contusion injury in the rat by monitoring the expression of the nuclear protein encoded by the c-fos gene, an activity-dependent gene, in spinal cord and brainstem regions. Rats were anesthetized with urethane and the injury was produced by dropping a 5-g weight from 20.0 cm onto the exposed dura at the T10-L1 vertebral level (contusion group). The spinal cord was exposed but not lesioned in anesthetized control animals (laminectomy group); intact animals were also subjected to anesthesia (intact control). Behavioral alterations were analyzed by Tarlov/Bohlman scores, 2 h after the procedures and the animals were then perfused for immunocytochemistry. The patterns of Fos-like immunoreactivity (FLI) which were site-specific, reproducible and correlated with spinal laminae that respond predominantly to noxious stimulation or injury: laminae I-II (outer substantia gelatinosa) and X and the nucleus of the intermediolateral cell column. At the brain stem level FLI was detected in the reticular formation, area postrema and solitary tract nucleus of lesioned animals. No Fos staining was detected by immunocytochemistry in the intact control group. However, detection of FLI in the group submitted to anesthesia and surgical procedures, although less intense than in the lesion group, indicated that microtraumas may occur which are not detected by the Tarlov/Bohlman scores. There is both a local and remote effect of a distal contusion on the spinal cord of rats, implicating sensory neurons and centers related to autonomic control in the reaction to this kind of injury.

Pharmacological differences between memory consolidation of habituation to an open field and inhibitory avoidance learning

Rats implanted bilaterally with cannulae in the CA1 region of the dorsal hippocampus or the entorhinal cortex were submitted to either a one-trial inhibitory avoidance task, or to 5 min of habituation to an open field. Immediately after training, they received intrahippocampal or intraentorhinal 0.5-µl infusions of saline, of a vehicle (2% dimethylsulfoxide in saline), of the glutamatergic N-methyl-D-aspartate (NMDA) receptor antagonist 2-amino-5-phosphono pentanoic acid (AP5), of the protein kinase A inhibitor Rp-cAMPs (0.5 µg/side), of the calcium-calmodulin protein kinase II inhibitor KN-62, of the dopaminergic D1 antagonist SCH23390, or of the mitogen-activated protein kinase kinase inhibitor PD098059. Animals were tested in each task 24 h after training. Intrahippocampal KN-62 was amnestic for habituation; none of the other treatments had any effect on the retention of this task. In contrast, all of them strongly affected memory of the avoidance task. Intrahippocampal Rp-cAMPs, KN-62 and AP5, and intraentorhinal Rp-cAMPs, KN-62, PD098059 and SCH23390 caused retrograde amnesia. In view of the known actions of the treatments used, the present findings point to important biochemical differences in memory consolidation processes of the two tasks.

Apoptosis of sensory neurons and satellite cells after sciatic nerve transection in C57BL/6J mice

The rate of axonal regeneration, after sciatic nerve lesion in adult C57BL/6J mice, is reduced when compared to other isogenic strains. It was observed that such low regeneration was not due just to a delay, since neuronal death was observed. Two general mechanisms of cell death, apoptosis and necrosis, may be involved. By using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) technique, we demonstrated that a large number of sensory neurons, as well as satellite cells found in the dorsal root ganglia, were intensely labeled, thus indicating that apoptotic mechanisms were involved in the death process. Although almost no labeled neurons or satellite cells were observed one week after transection, a more than ten-fold increase in TUNEL labeling was detected after two weeks. The results obtained with the C57BL/6J strain were compared with those of the A/J strain, which has a much higher peripheral nerve regeneration potential. In A/J mice, almost no labeling of sensory neurons or satellite cells was observed after one or two weeks, indicating the absence of neuronal loss. Our data confirm previous observations that approximately 40% of C57BL/6J sensory neurons die after sciatic nerve transection, and indicate that apoptotic events are involved. Also, our observations reinforce the hypothesis that the low rate of axonal regeneration occurring in C57BL/6J mice may be the result of a mismatch in the timing of the neurons need for neurotrophic substances, and production of the latter by non-neuronal cells in the distal stump.

Behavioral and electroencephalographic analysis of seizures induced by intrahippocampal injection of granulitoxin, a neurotoxic peptide from the sea anemone Bunodosoma granulifera

In this study, the behavioral and electroencephalographic (EEG) analysis of seizures induced by the intrahippocampal injection in rats of granulitoxin, a neurotoxic peptide from the sea anemone Bunodosoma granulifera, was determined. The first alterations occurred during microinjection of granulitoxin (8 µg) into the dorsal hippocampus and consisted of seizure activity that began in the hippocampus and spread rapidly to the occipital cortex. This activity lasted 20-30 s, and during this period the rats presented immobility. During the first 40-50 min after its administration, three to four other similar short EEG seizure periods occurred and the rats presented the following behavioral alterations: akinesia, facial automatisms, head tremor, salivation, rearing, jumping, barrel-rolling, wet dog shakes and forelimb clonic movements. Within 40-50 min, the status epilepticus was established and lasted 8-12 h. These results are similar to those observed in the acute phase of the pilocarpine model of temporal lobe epilepsy and suggest that granulitoxin may be a useful tool not only to study the sodium channels, but also to develop a new experimental model of status epilepticus.