Evidence of reciprocal connections between the dorsal raphe nucleus and the retina in the monkey Cebus apella

Possible connections between the retina and the raphe nuclei were investigated in the monkey Cebus apella by intraocular injection of cholera toxin B subunit (CTb). CTb-positive fibers were seen in the lateral region of the dorsal raphe nucleus (DR) on the side contralateral to the injection, and a few labeled perikarya were observed in the lateral portion of the DR on the ipsilateral side. Our findings suggest that direct and reciprocal connections between the retina and DR may exist in Cebus apella. These connections might be part of an important pathway through which the light/dark cycle influences the Activity and/or functional status of raphe neurons, with potential effects on a broad set of neural and behavioral circuits. (c) 2007 Elsevier B.V. All rights reserved.

Sidestream cigarette smoke effects on cardiovascular responses in conscious rats: involvement of oxidative stress in the fourth cerebral ventricle

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

What is your diagnosis? Hepatosplenomegaly in a howler monkey (Alouatta fusca)

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

Comparison of the cardio-respiratory effects of methadone and morphine in conscious dogs

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

Distribution of NADPH-diaphorase-positive neurons in the prefrontal cortex of the Cebus monkey

We studied the distribution of NADPH-diaphorase (NADPH-d) activity in the prefrontal cortex of normal adult Cebus apella monkeys using NADPH-d histochemical protocols. The following regions were studied: granular areas 46 and 12, dysgranular areas 9 and 13, and agranular areas 32 and Oap. NADPH-d-positive neurons were divided into two distinct types, both non-pyramidal. Type I neurons had a large soma diameter (17.24 +/- 1.73 pm) and were densely stained. More than 90% of these neurons were located in the subcortical white matter and infragranular layers. The remaining type I neurons were distributed in the supragranular layers. Type II neurons had a small, round or oval soma (9.83 +/- 1.03 mu m), and their staining pattern varied markedly. Type II neurons were distributed throughout the cortex, with their greatest numerical density being observed in layers II and III. In granular areas, the number of type II neurons was up to 20 times that of type I neurons, but this proportion was smaller in agranular areas. Areal density of type II neurons was maximum in the supragranular layers of granular areas and minimum in agranular areas. Statistical analysis revealed that these areal differences were significant when comparing some specific areas. In conclusion, our results indicate a predominance of NADPH-d-positive cells in supragranular layers of granular areas in the Cebus prefrontal cortex. These findings support previous observations on the role of type II neurons as a new cortical nitric oxide source in supragranular cortical layers in primates, and their potential contribution to cortical neuronal activation in advanced mammals. (c) 2006 Elsevier B.V. All rights reserved.

Short-term vs long-term calcium hydroxide therapy after immediate tooth replantation: a histomorphometric study in monkey's teeth

Endodontic treatment is an important step of tooth replantation protocols, but the ideal moment for definitive obturation of replanted teeth has not yet been established. In this study, a histomorphometric analysis was undertaken to evaluate the repair process on immediate replantation of monkeys teeth after calcium hydroxide (CH) therapy for 1 and 6 months followed by root canal filling with a CH-based sealer (Sealapex (R)). The maxillary and mandibular lateral incisors of five female Cebus apella monkeys were extracted, kept in sterile saline for 15 min, replanted and splinted with stainless steel orthodontic wire and composite resin for 10 days. In Group I (control), definitive root canal filling was performed before tooth extraction. In Groups II and III, CH therapy started after removal of splint, and definitive root canal filling was performed 1 and 6 months later, respectively. The animals were euthanized 9 months after replantation, and specimens were processed for histomorphometric analysis. In all groups, epithelial attachment occurred at the cementoenamel junction or very close to this region; the areas of resorption on root surface had small extension and depth and were repaired by newly formed cementum; and the periodontal ligament was organized. Statistical analysis of the scores obtained for the histomorphometric parameters did not show any statistically significant difference (P = 0.1221) among the groups. The results suggests that when endodontic treatment is initiated 10 days after immediate replantation and an antibiotic regimen is associated, definitive root canal filling can be performed after a short-term CH therapy.

Immunocytochemical characterization of the pregeniculate nucleus and distribution of retinal and neuropeptide Y terminals in the suprachiasmatic nucleus of the Cebus monkey

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

Cyto-, myelo- and chemoarchitecture of the prefrontal cortex of the Cebus monkey

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

Subgingival microbiota from Cebus apella (capuchin monkey) with different periodontal conditions

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

Lateral hypothalamus lesions influences water and salt intake, and sodium and urine excretion, and arterial blood pressure induced by L-NAME and FK 409 injections into median preoptic nucleus in conscious rats

Male Holtzman rats weighting 200-250 g were anesthetized with zoletil 50 mg/Kg (tiletamine chloridrate 125,0 mg and zolazepan chloridrate 125,0 mg) into quadriceps muscle and submitted an electrolytic lesion of the lateral hypothalamus (LH) and a stainless steel cannula was implanted into their median preoptic nucleus (MnPO). We investigated the effects of the injection into the (MnPO) of FK 409 (20 mug/0.5 mul), a nitric oxide (NO) donor, and N-W-nitro-L-arginine methyl ester (L-NAME) 40 mug/0.5 mul, a nitric oxide synthase inhibitor (NOSI), on the water and sodium appetite and the natriuretic, diuretic and cardiovascular effects induced by injection of L-NAME and FK 409 injected into MnPO in rats with LH lesions. Controls were injected with a similar volume of 0.15 M NaCl. L-NAME injected into MnPO produced an increase in water and sodium intake and in sodium and urine excretion and increase de mean arterial pressure (MAP). FK 409 injected into MnPO did not produce any change in the hydro electrolytic and cardiovascular parameters in LH-sham and lesioned rats. FK 409 injected before L-NAME attenuated its effects. These data show that electrolytic lesion of the LH reduces fluid and sodium intake as well as sodium and urine excretion, and the pressor effect induced by L-NAME. LH involvement with NO of the MnPO excitatory and inhibitory mechanisms related to water and sodium intake, sodium excretion and cardiovascular control is suggested. (C) 2004 Elsevier B.V. All rights reserved.

CARDIOVASCULAR EFFECTS OF CENTRAL CLONIDINE IN CONSCIOUS RATS AFTER HYPOTHALAMIC-LESIONS

The central injection of clonidine (an alpha-2-adrenoceptor agonist) in conscious normotensive rats produces hypertensive responses and bradycardia. The present study was performed to investigate the effect of electrolytic lesions in the anteroventral third ventricle (AV3V) region or in the lateral hypothalamus (LH) on the pressor and bradycardic responses induced by central clonidine in rats. Mean arterial pressure and heart rate were recorded in sham or AV3V-lesioned rats with cerebral stainless steel cannulae implanted into the lateral cerebral ventricle (ICV) or LH. and in sham or bilateral LH-lesioned rats with cannulae-implanted ICV. The injection of clonidine (40 nmol) ICV or into the LH of sham rats produced a pressor response (37 +/- 2-48 +/- 3 mmHg) and bradycardia (-45 +/- 10--93 +/- 6 bpm). After AV3V-lesion (3 and 12 days) or LH-lesion (3 days) the pressor response was abolished and a small hypotensive response was induced by the injection of clonidine (-1 +/- 3--16 +/- 3 mmHg). The bradycardia (-27 +/- 6--57 +/- 11 bpm) was reduced, but not abolished by the lesions. These results show that the AV3V region and LH are important cerebral structures that participate in the excitatory pathways involved in the pressor response to central clonidine in rats. They also suggest that, in the absence of these pressor pathways, the hypotensive responses to central clonidine may appear in conscious rats.

LESIONS OF THE LATERAL HYPOTHALAMUS IMPAIR THE PRESSOR-RESPONSE TO CLONIDINE INJECTED INTO THE MEDIAL SEPTAL AREA OF CONSCIOUS RATS

The central injection of clonidine (an alpha-2-adrenoceptor agonist) in conscious normotensive rats produces hypertensive responses and bradycardia. The present study was performed to investigate the effect of electrolytic lesions of the lateral hypothalamus (LH) on the pressor and bradycardic responses induced by clonidine injected into the medial septal area (MSA) in conscious and unrestrained rats. Male Holtzman rats weighing 250-300 g were used. Mean arterial pressure and heart rate were recorded in sham- or bilateral LH-lesioned rats with a cerebral stainless steel cannula implanted into the MSA. The injection of clonidine (40 nmol/mu-l) into the MSA of sham rats (N = 8) produced a pressor response (36 +/- 7 mmHg, P<0.05) and bradycardia (-70 +/- 13 bpm, P<0.05) compared to saline. Fourteen days after LH-lesion (N = 9) the pressor response was reduced (9 +/- 10 mmHg, P<0.05) but no change was observed in the bradycardia (-107 +/- 24 bpm). These results show that LH is an important area involved in the pressor response to clonidine injected into the MSA of rats.

THE ROLE OF ANGIOTENSIN AT1 RECEPTORS IN THE DIURETIC, NATRIURETIC, KALIURETIC AND BLOOD-PRESSURE RESPONSES INDUCED BY ANGIOTENSIN-II ACTIVATION OF THE MEDIAN PREOPTIC NUCLEUS IN CONSCIOUS RATS

We determined the effects of two classical angiotensin II (ANG II) antagonists, [Sar(1), Ala(8)]-ANG II and [Sar(1), Thr(8)]-ANG II, and losartan (a nonpeptide and selective antagonist for the AT 1 angiotensin receptors) on diuresis, natriuresis, kaliuresis and arterial blood pressure induced by ANG II administration into the median preoptic nucleus (MnPO) of male Holtzman rats weighing 250-300 g. Urine was collected in rats submitted to a water load (5% body weight) by gastric gavage, followed by a second water load (5% body weight) 1 h later. The volume of the drug solutions injected was 0.5 mu l over 10-15 s. Pre-treatment with [Sar(1), Ala(8)]-ANG II (12 rats) and [Sar(1), Thr(8)]-ANG II (9 rats), at the dose of 60 ng reduced (13.7 +/- 1.0 vs 11.0 +/- 1.0 and 10.7 +/- 1.2, respectively), whereas losartan (14 rats) at the dose of 160 ng totally blocked (13.7 +/- 1.0 vs 7.6 +/- 1.5) the urine excretion induced by injection of 12 ng of ANG II (14 rats). [Sar(1), Ala(8)]-ANG II impaired Na+ excretion (193 +/- 16 vs 120 +/- 19): whereas [Sar(1), Thr(8)]-ANG II and losartan blocked Na+ excretion (193 +/- 16 vs 77 +/- 15 and 100 +/- 12, respectively) induced by ANG II. Similar effects induced by ANG II on K+ excretion were observed with [Sar(1), Ala(8)]-ANG II, [Sar(1), Thr(8)]-ANG II, and losartan pretreatment (133 +/- 18 vs 108 +/- 11, 80 +/- 12, and 82 +/- 15, respectively). The same doses as above of [Sar(1), Ala(8)]-ANG II (8 rats), [Sar(1), Thr(8)]-ANG II (8 rats). and losartan (9 rats) blocked the increase in the arterial blood pressure induced by 12 ng of ANG II (12 rats) (32 +/- 4 ru 4 +/- 2, 3.5 +/- 1, and 2 +/- 1: respectively. The results indicate that the AT1 receptor subtype participates in the increases of diuresis, natriuresis. kaliuresis and arterial blood pressure induced by the administration of ANG II into the MnPO.

DIET OF THE BROWN HOWLER MONKEY ALOUATTA-FUSCA IN A FOREST FRAGMENT IN SOUTHEASTERN BRAZIL

The diet of the brown howler monkey Alouatta fusca in a 250 ha forest fragment in southeastern Brazil was studied for 42 consecutive months. The howlers were observed eating in 366 feeding records (one group or a monkey eating a single plant) of 52 plant species. Twenty three percent of the leaves and 52 % of the flowers in the howler's diet came from lianas. Eighteen fruit species were recorded as being dispersed by howlers and seeds of two liana species were eaten. In small forest fragments where most large specialized frugivores are absent howlers may be the main seed disperser of large fruits.