Atividade espontânea e estimulação do inseto (T. molitor)

The heart of the insect is essentially myogenic, in others words, electrical activity and spontaneous contractions are generated by their muscle cells. However, the nature of pacemaker activity is not yet fully elucidated. One aspect that deserves attention, beyond the pacemaker activity, is the amplitude of heart contractions of the insect. For this, it is necessary that the heart to be stimulated electrically to the frequency to be controlled. In the present work, it was developed a method of stimulation (preparation and instrumentation). The contractile activity of the heart of the insect remained regular when stimulated at frequencies lightly above the spontaneous frequency. To characterize excitability of the preparation the intensity-duration curve was determined

Bases Científicas da Acupuntura

Acupuncture is a technique belonging to traditional Chinese medicine that has existed for over 3000 years. It consists of stimuli by pressure, needling, heat and electrical stimulation of the skin at specific points to restore the health of patients. This technique has been increasingly incorporated into the West and therefore the research explaining its various mechanisms become very important to translate these ancient skills. This article is a literature review summarizing the basic concepts, historical and local, anti-inflammatory and neurological effects acupuncture in the body

Acupuntura veterinária em pequenos animais

Acupuncture is one of the oldest forms of treatment, which is based in the grounds of Traditional Chinese Medicine. Despite the ancient history, it’s not completely widespread in Brazil, neither so comprehensive in veterinary medicine as used in humans. The technique of inserting needles into acupuncture points, can also be stimulated by heat, electrical stimulation or implants of metal, is mainly focused on neuromuscular disorders in small animals. The difficulty of comprehension of language and the lack of cientific bases restricted the possible applications of acupuncture. This work will address some of the clinical situations this complementary treatment can act, such as neurological, cardiorespiratory, reproductive, gastrointestinal, immunological, and postoperative intensive care

Estimulação elétrica com eletrodos não implantáveis no tratamento da bexiga hiperativa em adultos: revisão sistemática de ensaios clínicos randonizados

Pós-graduação em Bases Gerais da Cirurgia - FMB

Identificação de funções de transferência de ordem fracionária utilizando como entrada um degrau

Pós-graduação em Engenharia Elétrica - FEIS

Reabilitação do assoalho pélvico em pacientes com incontinência urinária pós prostatectomia radical

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

Análise do exercício físico e eletroestimulção do músculo tibial cranial após neurorrafia término-lateral do nervo fibular em ratos

Pós-graduação em Bases Gerais da Cirurgia - FMB

Efeitos cardiorrespiratórios promovidos pelo posicionamento trendelenburg reverso a cinco e dez graus em bezerros anestesiados pelo sevofluorano: Marcelo Augusto de Araújo. -

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

Activation of 5-HT2C receptors in the dorsal periaqueductal gray increases antinociception in mice exposed to the elevated plus-maze

Several findings have pointed to the role of the dorsal periaqueductal gray (dPAG) serotonin 5-HT1A and 5-HT2(A-C) receptor subtypes in the modulation of defensive behavior in animals exposed to the elevated plus-maze (EPM). Besides displaying anxiety-like behavior, rodents also exhibit antinociception in the EPM. This study investigated the effects of intra-dPAG injections of 5-HT1A and 5-HT2B/2C receptor ligands on EPM-induced antinociception in mice. Male Swiss mice received 0.1 mu l intra-dPAG injections of vehicle, 5.6 and 10 nmol of 8-OHDPAT, a 5-HT1A receptor agonist (Experiment 1), or 0.01, 0.03 and 0.1 nmol of mCPP, a 5-HT2B/2C receptor agonist (Experiment 2). Five minutes later, each mouse received an intraperitoneal injection of 0.6% acetic acid (0.1 ml/10 g body weight; nociceptive stimulus) and was individually confined in the open (OA) or enclosed (EA) arms of the EPM for 5 min, during which the number of abdominal writhes induced by the acetic acid was recorded. While intra-dPAG injection of 8-OHDPAT did not change open-arm antinociception (OAR). mCPP (0.01 nmol) enhanced it. Combined injections of ketanserin (10 nmol/0.1 mu l), a 5-HT2A/2C receptor antagonist, and 0.01 nmol of mCPP (Experiment 3), selectively and completely blocked the OAR enhancement induced by mCPP. Although intra-dPAG injection of mCPP (0.01 nmol) also produced antinociception in EA-confined mice (Experiment 2), this effect was not confirmed in Experiment 3. Moreover, no other compound changed the nociceptive response in EA-confined animals. These results suggest that the 5-HT2C receptors located within the PAG play a role in this type of environmentally induced pain inhibition in mice. (c) 2012 Elsevier B.V. All rights reserved.

Medial amygdaloid nucleus 5-HT2C receptors are involved in the hypophagic effect caused by zimelidine in rats

The medial amygdaloid nucleus (MeA) is a sub-region of the amygdaloid complex that has been described as participating in food intake regulation. Serotonin has been known to play an important role in appetite and food intake regulation. Moreover, serotonin 5-HT2C and 5-HT1A receptors appear to be critical in food intake regulation. We investigated the role of the serotoninergic system in the MeA on feeding behavior regulation in rats. The current study examined the effects on feeding behavior regulation of the serotonin reuptake inhibitor, zimelidine, administered directly into the MeA or given systemically, and the serotoninergic receptors mediating its effect. Our results showed that microinjection of zimelidine (0.2, 2 and 20 nmol/100 nL) into the MeA evoked dose dependent hypophagic effects in fasted rats. The selective 5-HT1A receptor antagonist WAY-100635 (18.5 nmol/100 nL) or the 5-HT1B receptor antagonist SB-216641 microinjected bilaterally into the MeA did not change the hypophagic effect evoked by local MeA zimelidine treatment. However, microinjection of the selective 5-HT2C receptor antagonist SB-242084 (10 nmol/100 nL) was able to block the hypophagic effect of zimelidine. Moreover, microinjection of the 5-HT2C receptor antagonist SB-242084 into the MeA also blocked the hypophagic effect caused by zimelidine administered systemically. These results suggest that MeA 5-HT2C receptors modulate the hypophagic effect caused by local MeA administration as well as by systemic zimelidine administration. Furthermore, 5-HT2C into the MeA could be a potential target for systemic administration of zimelidine. (C) 2012 Elsevier Ltd. All rights reserved.

The Dorsolateral Periaqueductal Gray and Its Role in Mediating Fear Learning to Life Threatening Events

The dorsolateral column of the periaqueductal gray (dlPAG) integrates aversive emotional experiences and represents an important site responding to life threatening situations, such as hypoxia, cardiac pain and predator threats. Previous studies have shown that the dorsal PAG also supports fear learning; and we have currently explored how the dlPAG influences associative learning. We have first shown that N-methyl-D-aspartate (NMDA) 100 pmol injection in the dlPAG works as a valuable unconditioned stimulus (US) for the acquisition of olfactory fear conditioning (OFC) using amyl acetate odor as conditioned stimulus (CS). Next, we revisited the ascending projections of the dlPAG to the thalamus and hypothalamus to reveal potential paths that could mediate associative learning during OFC. Accordingly, the most important ascending target of the dlPAG is the hypothalamic defensive circuit, and we were able to show that pharmacological inactivation using beta-adrenoceptor blockade of the dorsal premammillary nucleus, the main exit way for the hypothalamic defensive circuit to thalamo-cortical circuits involved in fear learning, impaired the acquisition of the OFC promoted by NMDA stimulation of the dlPAG. Moreover, our tracing study revealed multiple parallel paths from the dlPAG to several thalamic targets linked to cortical-hippocampal-amygdalar circuits involved in fear learning. Overall, the results point to a major role of the dlPAG in the mediation of aversive associative learning via ascending projections to the medial hypothalamic defensive circuit, and perhaps, to other thalamic targets, as well. These results provide interesting perspectives to understand how life threatening events impact on fear learning, and should be useful to understand pathological fear memory encoding in anxiety disorders.

Metabolic and functional effects of beta-hydroxy-beta-methylbutyrate (HMB) supplementation in skeletal muscle

Beta-hydroxy-beta-methylbutyrate (HMB) is a metabolite derived from leucine. The anti-catabolic effect of HMB is well documented but its effect upon skeletal muscle strength and fatigue is still uncertain. In the present study, male Wistar rats were supplemented with HMB (320 mg/kg per day) for 4 weeks. Placebo group received saline solution only. Muscle strength (twitch and tetanic force) and resistance to acute muscle fatigue of the gastrocnemius muscle were evaluated by direct electrical stimulation of the sciatic nerve. The content of ATP and glycogen in red and white portions of gastrocnemius muscle were also evaluated. The effect of HMB on citrate synthase (CS) activity was also investigated. Muscle tetanic force was increased by HMB supplementation. No change was observed in time to peak of contraction and relaxation time. Resistance to acute muscle fatigue during intense contractile activity was also improved after HMB supplementation. Glycogen content was increased in both white (by fivefold) and red (by fourfold) portions of gastrocnemius muscle. HMB supplementation also increased the ATP content in red (by twofold) and white (1.2-fold) portions of gastrocnemius muscle. CS activity was increased by twofold in red portion of gastrocnemius muscle. These results support the proposition that HMB supplementation have marked change in oxidative metabolism improving muscle strength generation and performance during intense contractions.

Endogenous opioid peptide-mediated neurotransmission in central and pericentral nuclei of the inferior colliculus recruits mu(1)-opioid receptor to modulate post-ictal antinociception

Background: The aim of the present work was to investigate the involvement of the mu(1)-endogenous opioid peptide receptor-mediated system in post-ictal antinociception. Methods: Antinociceptive responses were determined by the tail-flick test after pre-treatment with the selective mu(1)-opioid receptor antagonist naloxonazine, peripherally or centrally administered at different doses. Results: Peripheral subchronic (24 h) pre-treatment with naloxonazine antagonised the antinociception elicited by tonic-clonic seizures. Acute (10 min) pre-treatment, however, did not have the same effect. In addition, microinjections of naloxonazine into the central, dorsal cortical and external cortical nuclei of the inferior colliculus antagonised tonic-clonic seizure-induced antinociception. Neither acute (10-min) peripheral pre-treatment with naloxonazine nor subchronic intramesencephalic blockade of mu(1)-opioid receptors resulted in consistent statistically significant differences in the severity of tonic-clonic seizures shown by Racine's index (1972), although the intracollicular specific antagonism of mu(1)-opioid receptor decreased the duration of seizures. Conclusion: mu(1)-Opioid receptors and the inferior colliculus have been implicated in several endogenous opioid peptide-mediated responses such as antinociception and convulsion. The present findings suggest the involvement of mu(1)-opiate receptors of central and pericentral nuclei of the inferior colliculus in the modulation of tonic-clonic seizures and in the organisation of post-ictal antinociception. (C) 2011 Elsevier Ltd. All rights reserved.

Changes in FDB and soleus muscle activity after a train of stimuli during upright stance

Background: Evidence of self-sustained muscle activation following a brief electrical stimulation has been reported in the literature for certain muscles. Objectives: This report shows that the foot muscle (Flexor Digitorum Brevis - FDB) shows a self-sustained increase in muscle activity during upright stance in some subjects following a train of stimuli to the tibial nerve. Methods: Healthy subjects were requested to stand upright and surface EMG electrodes were placed on the FDB, Soleus and Tibialis Anterior muscles. After background muscle activity (BGA) acquisition, a 50 Hz train of stimuli was applied to the tibial nerve at the popliteal fossa. The root mean square values (RMS) of the BGA and the post-stimulus muscle activation were computed. Results: There was a 13.8% average increase in the FDB muscle EMG amplitude with respect to BGA after the stimulation was turned off. The corresponding post-stimulus Soleus EMG activity decreased by an average of 9.2%. We hypothesize that the sustained contraction observed in the FDB following stimulus may be evidence of persistent inward currents (PIC) generated in FDB spinal motoneurons. The post-stimulus decrease in soleus activity may have occurred due to the action of inhibitory interneurons caused by the PICs, which were triggered by the stimulus train. Conclusions: These sustained post-stimulation changes in postural muscle activity, found in different levels in different subjects, may be part of a set of possible responses that contribute to overall postural control.

Anti-Aversive Effects of Cannabidiol on Innate Fear-Induced Behaviors Evoked by an Ethological Model of Panic Attacks Based on a Prey vs the Wild Snake Epicrates cenchria crassus Confrontation Paradigm

Several pharmacological targets have been proposed as modulators of panic-like reactions. However, interest should be given to other potential therapeutic neurochemical agents. Recent attention has been given to the potential anxiolytic properties of cannabidiol, because of its complex actions on the endocannabinoid system together with its effects on other neurotransmitter systems. The aim of this study was to investigate the effects of cannabidiol on innate fear-related behaviors evoked by a prey vs predator paradigm. Male Swiss mice were submitted to habituation in an arena containing a burrow and subsequently pre-treated with intraperitoneal administrations of vehicle or cannabidiol. A constrictor snake was placed inside the arena, and defensive and non-defensive behaviors were recorded. Cannabidiol caused a clear anti-aversive effect, decreasing explosive escape and defensive immobility behaviors outside and inside the burrow. These results show that cannabidiol modulates defensive behaviors evoked by the presence of threatening stimuli, even in a potentially safe environment following a fear response, suggesting a panicolytic effect. Neuropsychopharmacology (2012) 37, 412-421; doi:10.1038/npp.2011.188; published online 14 September 2011