Shape isomerism and shape coexistence effects on the Coulomb energy differences in the N = Z nucleus As-66 and neighboring T=1 multiplets

Excited states of the N = Z = 33 nucleus As-66 have been populated in a fusion-evaporation reaction and studied using gamma-ray spectroscopic techniques. Special emphasis was put into the search for candidates for the T = 1 states. A new 3(+) isomer has been observed with a lifetime of 1.1(3) ns. This is believed to be the predicted oblate shape isomer. The excited levels are discussed in terms of the shell model and of the complex excited Vampir approaches. Coulomb energy differences are determined from the comparison of the T = 1 states with their analog partners. The unusual behavior of the Coulomb energy differences in the A = 70 mass region is explained through different shape components (oblate and prolate) within the members of the same isospin multiplets. This breaking of the isospin symmetry is attributed to the correlations induced by the Coulomb interaction.

Searching for resonances in the unbound Be-6 nucleus by using a radioactive Be-7 beam

Knowledge of the He-3(He-3,2p)He-4 reaction is important for understanding stellar burning and solar neutrino production. Previous measurements have found a surprisingly large rise in the cross section at low energies that could be due to a low-energy resonance in the He-3 + He-3 (Be-6) system or electron screening. In the Be-6 nucleus, however, no excited states have been observed above the first 2(+) state at E (x) = 1.67 MeV up to 23 MeV, even though several are expected. The H-2(Be-7,H-3)Be-6 reaction has been studied for the first time to search for resonances in the Be-6 nucleus that may affect our understanding of the He-3(He-3,2p)He-4 reaction. A 100-MeV radioactive Be-7 beam from the Holifield Radioactive Ion Beam Facility (HRIBF) was used to bombard CD2 targets, and tritons were detected by using the silicon detector array (SIDAR). A combination of reaction mechanisms appears to be necessary to explain the observed triton energy spectrum.

mu(1)- and 5-HT1-dependent mechanisms in the anterior pretectal nucleus mediate the antinociceptive effects of retrosplenial cortex stimulation in rats

Aim: This study examines if injection of cobalt chloride (CoCl2) or antagonists of muscarinic cholinergic (atropine), mu(1)-opioid (naloxonazine) or 5-HT1 serotonergic (methiothepin) receptors into the dorsal or ventral portions of the anterior pretectal nucleus (APtN) alters the antinociceptive effects of stimulating the retrosplenial cortex (RSC) in rats. Main method: Changes in the nociceptive threshold were evaluated using the tail flick or incision pain tests in rats that were electrically stimulated at the RSC after the injection of saline, CoCl2 (1 mM, 0.10 mu L) or antagonists into the dorsal or ventral APtN. Key findings: The injection of CoCl2, naloxonazine (5 mu g/0.10 mu L) or methiothepin (3 mu g/0.10 mu L) into the dorsal APtN reduced the stimulation-produced antinociception from the RSC in the rat tail flick test. Reduction of incision pain was observed following stimulation of the RSC after the injection of the same substances into the ventral APtN. The injection of atropine (10 ng/0.10 mu L) or ketanserine (5 mu g/0.10 mu L) into the dorsal or ventral APtN was ineffective against the antinociception resulting from RSC stimulation. Significance: mu(1)-opioid- and 5-HT1-expressing neurons and cell processes in dorsal and ventral APtN are both implicated in the mediation of stimulation-produced antinociception from the RSC in the rat tail flick and incision pain tests, respectively. (c) 2012 Elsevier Inc. All rights reserved.

beta-ADRENOCEPTORS IN THE MEDIAL AMYGDALOID NUCLEUS MODULATE THE TACHYCARDIAC RESPONSE TO RESTRAINT STRESS IN RATS

In the present study, we investigated the involvement of beta-adrenoceptors in the medial amygdaloid nucleus (MeA) in cardiovascular responses evoked in rats submitted to an acute restraint stress. We first pretreated Wistar rats with the nonselective beta-adrenoceptor antagonist propranolol microinjected bilaterally into the MeA (10, 15, and 20 nmol/100 nL) 10 min before exposure to acute restraint. The pretreatment with propranolol did not affect the blood pressure (BP) increase evoked by restraint. However, it increased the tachycardiac response caused by acute restraint when animals were pretreated with a dose of 15 nmol, without a significant effect on the BP response. This result indicates that beta-adrenoceptors in the MeA have an inhibitory influence on restraint-evoked heart rate (HR) changes. Pretreatment with the selective beta(2)-adrenoceptor antagonist ICI 118,551 (10, 15, and 20 nmol/100 nL) significantly increased the restraint-evoked tachycardiac response after doses of 15 and 20 nmol, an effect that was similar to that observed after the pretreatment with propranolol at a dose of 15 nmol, without a significant effect on the BP response. Pretreatment of the MeA with the selective beta(1)-adrenoceptor antagonist CGP 20712 (10, 15, and 20 nmol/100 nL) caused an opposite effect on the HR response, and a significant decrease in the restraint-evoked tachycardia was observed only after the dose of 20 nmol, without a significant effect on the BP response. Because propranolol is an equipotent antagonist of both beta(1) and beta(2)-adrenoceptors, and opposite effects were observed after the treatment with the higher doses of the selective antagonists ICI 118,551 and CGP 20712, the narrow window in the dose-response to propranolol could be explained by a functional antagonism resulting from the simultaneous inhibition of beta(1) and beta(2)-adrenoceptors by the treatment with propranolol. The present results suggest that beta(2)-adrenoceptors have an inhibitory influence on the restraint-evoked tachycardiac response, whereas beta(1)-adrenoceptors have a facilitatory influence on the restraint-evoked tachycardiac response. (c) 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

PARAVENTRICULAR AND SUPRAOPTIC NUCLEI OF THE HYPOTHALAMUS MEDIATE CARDIOVASCULAR RESPONSES EVOKED BY THE MICROINJECTION OF NORADRENALINE INTO THE MEDIAL AMYGDALOID NUCLEUS OF THE RAT BRAIN

The medial amygdaloid nucleus (MeA) is a part of the limbic system and is involved in cardiovascular modulation. We previously reported that microinjection of noradrenaline (NA) into the MeA of unanesthetized rats caused pressor and bradycardiac responses, which were mediated by acute vasopressin release into the systemic circulation. In the present study, we tested the possible involvement of magnocellular neurons of the paraventricular (PVN) and/or supraoptic (SON) of the hypothalamus that synthesize vasopressin in the cardiovascular pathway activated by the microinjection of NA into the MeA. Pressor and bradycardiac responses to the microinjection of NA (27 nmol/100 nL) into the MeA were blocked by pretreatment of either the PVN or the SON with cobalt chloride (CoCl2, 1 mM/100 nL), thus indicating that both hypothalamic nuclei mediate the cardiovascular responses evoked by microinjection of NA Into the MeA. Our results suggest that the pressor and bradycardiac response caused by the microinjection of NA into the MeA is mediated by magnocellular neurons in both the PVN and SON. (C) 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

Result on speech perception after conversion from Spectra (R) to Freedom (R)

New technology in the Freedom (R) speech processor for cochlear implants was developed to improve how incoming acoustic sound is processed; this applies not only for new users, but also for previous generations of cochlear implants. Aim: To identify the contribution of this technology - the Nucleus 22 (R) - on speech perception tests in silence and in noise, and on audiometric thresholds. Methods: A cross-sectional cohort study was undertaken. Seventeen patients were selected. The last map based on the Spectra (R) was revised and optimized before starting the tests. Troubleshooting was used to identify malfunction. To identify the contribution of the Freedom (R) technology for the Nucleus22 (R), auditory thresholds and speech perception tests were performed in free field in soundproof booths. Recorded monosyllables and sentences in silence and in noise (SNR = 0dB) were presented at 60 dBSPL. The nonparametric Wilcoxon test for paired data was used to compare groups. Results: Freedom (R) applied for the Nucleus22 (R) showed a statistically significant difference in all speech perception tests and audiometric thresholds. Conclusion: The reedom (R) technology improved the performance of speech perception and audiometric thresholds of patients with Nucleus 22 (R).

Differential projections from the lateral habenula to the rostromedial tegmental nucleus and ventral tegmental area in the rat

The mesopontine rostromedial tegmental nucleus (RMTg) is a mostly ?-aminobutyric acid (GABA)ergic structure believed to be a node for signaling aversive events to dopamine (DA) neurons in the ventral tegmental area (VTA). The RMTg receives glutamatergic inputs from the lateral habenula (LHb) and sends substantial GABAergic projections to the VTA, which also receives direct projections from the LHb. To further specify the topography of LHb projections to the RMTg and VTA, small focal injections of the anterograde tracer Phaseolus vulgaris leucoagglutinin were aimed at different subdivisions of the LHb. The subnuclear origin of LHb inputs to the VTA and RMTg was then confirmed by injections of the retrograde tracer cholera toxin subunit b into the VTA or RMTg. Furthermore, we compared the topographic position of retrogradely labeled neurons in the RMTg resulting from VTA injections with that of anterogradely labeled axons emerging from the LHb. As revealed by anterograde and retrograde tracing, LHb projections were organized in a strikingly topographic manner, with inputs to the RMTg mostly arising from the lateral division of the LHb (LHbL), whereas inputs to the VTA mainly emerged from the medial division of the LHb (LHbM). In the RMTg, profusely branched LHb axons were found in close register with VTA projecting neurons and were frequently apposed to the latter. Overall, our findings demonstrate that LHb inputs to the RMTg and VTA arise from different divisions of the LHb and provide direct evidence for a disynaptic pathway that links the LHbL to the VTA via the RMTg. J. Comp. Neurol. 520:12781300, 2012. (C) 2011 Wiley Periodicals, Inc.

Cytokine inhibition and time-related influence of inflammatory stimuli on the hyperalgesia induced by the nucleus pulposus

The symptoms of lumbar disc herniation, such as low back pain and sciatica, have been associated with local release of cytokines following the inflammatory process induced by the contact of the nucleus pulposus (NP) with the spinal nerve. Using an animal experimental model of intervertebral disc herniation and behavioral tests to evaluate mechanical (electronic von Frey test) and thermal (Hargreaves Plantar test) hyperalgesia in the hind paw of rats submitted to the surgical model, this study aimed to detect in normal intervertebral disc the cytokines known to be involved in the mechanisms of inflammatory hyperalgesia, to observe if previous exposure of the intervertebral disc tissue to specific antibodies could affect the pain behavior (mechanical and thermal hyperalgesia) induced by the NP, and to observe the influence of the time of contact of the NP with the fifth lumbar dorsal root ganglion (L5-DRG) in the mechanical and thermal hyperalgesia. The cytokines present at highest concentrations in the rat NP were TNF-alpha, IL-1 beta and CINC-1. Rats submitted to the disc herniation experimental model, in which a NP from the sacrococcygeal region is deposited over the right L5-DRG, showed increased mechanical and thermal hyperalgesia that lasted at least 7 weeks. When the autologous NP was treated with antibodies against the three cytokines found at highest concentrations in the NP (TNF-alpha, IL-1 beta and CINC-1), there was decrease in both mechanical and thermal hyperalgesia in different time points, suggesting that each cytokine may be important for the hyperalgesia in different steps of the inflammatory process. The surgical remotion of the NP from herniated rats 1 week after the implantation reduced the hyperalgesia to the level similar to the control group. This reduction in the hyperalgesia was also observed in the group that had the NP removed 3 weeks after the implantation, although the intensity of the hyperalgesia did not decreased totally. The removal of the NP after 5 weeks did not changed the hyperalgesia observed in the hind paw, which suggests that the longer the contact of the NP with the DRG, the greater is the possibility of development of chronic pain. Together our results indicate that specific cytokines released during the inflammatory process induced by the herniated intervertebral disc play fundamental role in the development of the two modalities of hyperalgesia (mechanical and thermal) and that the maintenance of this inflammation may be the most important point for the chronification of the pain.

The medial amygdaloid nucleus is involved in the cardiovascular pathway activated by noradrenaline into the lateral septal area of rats

We have previously reported that noradrenaline (NA) microinjected into the lateral septal area (LSA) caused pressor and bradicardic responses that were mediated by vasopressin release into the circulation through the paraventricular nucleus of hypothalamus (PVN). Although PVN is the final structure involved in the cardiovascular responses caused by NA in the LSA, there is no evidence of direct connections between these areas, suggesting that some structures could be links in this pathway. In the present study, we verified the effect of reversible synaptic inactivation of the medial amygdaloid nucleus (MeA), bed nucleus of stria terminalis (BNST) or diagonal band of Broca (DBB) with Cobalt Chloride (CoCl2) on the cardiovascular response to NA microinjection into the LSA of unanesthetized rats. Male Wistar rats had guide cannulae implanted into the LSA and the MeA, BNST or DBB for drug administration, and a femoral catheter for blood pressure and heart rate recordings. Local microinjection of CoCl2 (1 mm in 100 nL) into the MeA significantly reduced the pressor and bradycardic responses caused by NA microinjection (21 nmol in 200 nL) into the LSA. In contrast, microinjection of CoCl2 into the BNST or DBB did not change the cardiovascular responses to NA into the LSA. The results indicate that synapses within the MeA, but not in BNST or DBB, are involved in the cardiovascular pathway activated by NA microinjection into the LSA.

alpha 1 and alpha 2-adrenoceptors in the medial amygdaloid nucleus modulate differently the cardiovascular responses to restraint stress in rats

Medial amygdaloid nucleus (MeA) neurotransmission has an inhibitory influence on cardiovascular responses in rats submitted to restraint, which are characterized by both elevated blood pressure (BP) and intense heart rate (HR) increase. In the present study, we investigated the involvement of MeA adrenoceptors in the modulation of cardiovascular responses that are observed during an acute restraint. Male Wistar rats received bilateral microinjections of the selective alpha 1-adrenoceptor antagonist WB4101 (10, 15, and 20 nmol/100 nL) or the selective alpha 2-adrenoceptor antagonist RX821002 (10, 15, and 20 nmol/nL) into the MeA, before the exposure to acute restraint. The injection of WB4101 reduced the restraint-evoked tachycardia. In contrast, the injection of RX821002 increased the tachycardia. Both drugs had no influence on BP increases observed during the acute restraint. Our findings indicate that alpha 1 and alpha 2-adrenoceptors in the MeA play different roles in the modulation of the HR increase evoked by restraint stress in rats. Results suggest that alpha 1-adrenoceptors and alpha 2-adrenoceptors mediate the MeA-related facilitatory and inhibitory influences on restraint-related HR responses, respectively. (C) 2012 Elsevier Ltd. All rights reserved.

Cannabidiol injected into the bed nucleus of the stria terminalis reduces the expression of contextual fear conditioning via 5-HT1A receptors

Systemic administration of cannabidiol (CBD) attenuates cardiovascular and behavioral changes induced by re-exposure to a context that had been previously paired with footshocks. Previous results from our group using cFos immunohistochemistry suggested that the bed nucleus of the stria terminalis (BNST) is involved in this effect. The mechanisms of CBD effects are still poorly understood, but could involve 5-HT1A receptor activation. Thus, the present work investigated if CBD administration into the BNST would attenuate the expression of contextual fear conditioning and if this effect would involve the activation of 5-HT1A receptors. Male Wistar rats with cannulae bilaterally implanted into the BNST were submitted to a 10 min conditioning session (six footshocks, 1.5 mA/3 s). Twenty-four hours later freezing and cardiovascular responses (mean arterial pressure and heart rate) to the conditioning box were measured for 10 min. CBD (15, 30 or 60 nmol) or vehicle was administered 10 min before the re-exposure to the aversive context. The second experiment was similar to the first one except that animals received microinjections of the 5-HT1A receptor antagonist WAY100635 (0.37 nmol) 5 min before CBD (30 nmol) treatment. The results showed that CBD (30 and 60 nmol) treatment significantly reduced the freezing and attenuated the cardiovascular responses induced by re-exposure to the aversive context. Moreover, WAY100635 by itself did not change the cardiovascular and behavioral response to context, but blocked the CBD effects. These results suggest that CBD can act in the BNST to attenuate aversive conditioning responses and this effect seems to involve 5-HT1A receptor-mediated neurotransmission.

Cochlear implant in postlingual children: functional results 10 years after the surgery

The benefits of cochlear implants (CI) for communication skills are obtained over the years. There are but a few studies regarding the long-term outcomes in postlingual deaf children who grew up using the electronic device. Aim: To assess the functional results in a group of postlingual children, 10 years after using a CI. Methods: Ten postlingual deaf children, implanted before 18 years of age, participated in this study. We assessed: sentence recognition and speech intelligibility. We documented: device use and function and the patient's academic/occupational status. Study design: series. Results: The mean scores were 73% for sentence recognition in silence and 40% in noise. The average write-down intelligibility score was 92% and the average rating-scale intelligibility score was 4.15. There were no cases of device failure. Regarding educational/vocational status, three subjects graduated from the University. Five quit education after completing high school. Eight subjects had a professional activity. Conclusion: This study showed that cochlear implantation is a safe and reliable procedure. The postlingual profoundly hearing-impaired children after 10 years of CI use developed satisfactory levels regarding speech perception and intelligibility, and completed at least high school and were inserted in the labor market. Clinical Trials Registry: NCT01400178.

Bioethics and medical/legal considerations on cochlear implants in children

Cochlear implants are the best treatment for congenital profound deafness. Pediatric candidates to implantation are seen as vulnerable citizens, and the decision of implanting cochlear devices is ultimately in the hands of their parents/guardians. The Brazilian Penal Code dictates that deaf people may enjoy diminished criminal capacity. Many are the bioethical controversies around cochlear implants, as representatives from the deaf community have seen in them a means of decimating their culture and intrinsic values. Objective: This paper aims to discuss, in bioethical terms, the validity of implanting cochlear hearing aids in children by analyzing their vulnerability and the social/cultural implications of the procedure itself, aside from looking into the medical/legal aspects connected to their criminal capacity. Materials and Methods: The topic was searched on databases Medline and Lilacs; ethical analysis was done based on principialist bioethics. Results: Cochlear implants are the best therapeutic option for people with profound deafness and are morally justified. The level of criminal capacity attributed to deaf people requires careful analysis of the subject's degree of understanding and determination when carrying out the acts for which he/she has been charged. Conclusion: Cochlear implants are morally valid. Implantations must be analyzed on an each case basis. ENT physicians bear the ethical responsibility for indicating cochlear implants and must properly inform the child's parents/guardians and get their written consent before performing the procedure.

Involvement of the paraventricular nucleus (PVN) of hypothalamus in the cardiovascular alterations to head up tilt in conscious rats

We evaluated the involvement of paraventricular nucleus (PVN) in the changes in mean arterial pressure (MAP) and heart rate (HR) during an orthostatic challenge (head up tilt, HUT). Adult male Wistar rats, instrumented with guide cannulas to PVN and artery and vein catheters were submitted to MAP and HR recording in conscious state and induction of HUT. The HUT induced an increase in MAP and HR and the pretreatment with prazosin and atenolol blocked these effects. After inhibition of neurotransmission with cobalt chloride (1 mM/100 nl) into the PVN the HR parameters did not change, however we observed a decrease in MAP during HUT. Our data suggest the involvement of PVN in the brain circuitry involved in cardiovascular adjustment during orthostatic challenges. (C) 2011 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Bed nucleus of the stria terminalis and the cardiovascular responses to chemoreflex activation

Several studies from our group have indicated that the BNST play an important role in baroreflex modulation. However, the involvement of the BNST in the chemoreflex activity is unknown. Thus, in the present study, we investigated the effect of the local bed nucleus of stria terminalis (BNST) neurotransmission inhibition by bilateral microinjections of the non-selective synaptic blocker cobalt chloride (CoCl2) on the cardiovascular responses to chemoreflex activation in rats. For this purpose, chemoreflex was activated with KCN (i.v.) before and after microinjections of CoCl2 into the BNST. Reversible BNST inactivation produced no significant changes in the magnitude and durations of both pressor and bradycardic responses to intravenous KCN infusion. These findings suggesting that BNST neurotransmission have not influence on both sympathoexcitatory and parasympathoexcitatory components of the peripheral chemoreflex activation. (C) 2012 Elsevier B.V. All rights reserved.