RESUMEN

Rendering tactile effects on a touch screen via electrovibration has many potential applications. However, our knowledge on tactile perception of change in friction and the underlying contact mechanics are both very limited. In this article, we investigate the tactile perception and the contact mechanics for a step change in friction under electrovibration during a relative sliding between a finger and the surface of a capacitive touch screen. First, we conduct magnitude estimation experiments to investigate the role of normal force and sliding velocity on the perceived tactile intensity for a step increase and decrease in friction, called rising friction (RF) and falling friction (FF). To investigate the contact mechanics involved in RF and FF, we then measure the frictional force, the apparent contact area, and the strains acting on the fingerpad during sliding at a constant velocity under three different normal loads using a custom-made experimental set-up. The results show that the participants perceived RF stronger than FF, and both the normal force and sliding velocity significantly influenced their perception. These results are supported by our mechanical measurements; the relative change in friction, the apparent contact area, and the strain in the sliding direction were all higher for RF than those for FF, especially for low normal forces. Taken together, our results suggest that different contact mechanics take place during RF and FF due to the viscoelastic behavior of fingerpad skin, and those differences influence our tactile perception of a step change in friction.

Asunto(s)

RESUMEN

The establishment of the intestinal microbiota is critical for the digestive and immune systems. We studied the early development of the rectal microbiota in horse, a hindgut fermenter, from birth until 7 days of age, by qPCR and 16S rRNA gene amplicon sequencing. To evaluate initial sources of the foal microbiota, we characterised dam fecal, vaginal and oral microbiotas. We utilised an amplicon sequence variant (ASV) pipeline to maximise resolution and reproducibility. Stringent ASV filtering based on prevalence and abundance in samples and controls purged contaminants while preserving intestinal taxa. Sampled within 20 minutes after birth, rectal meconium contained small amounts of diverse bacterial DNA, with a profile closer to mare feces than mouth. 24 hours after birth, rectum was colonised by Firmicutes and Proteobacteria, some foals dominated by single genera. At day 7, the rectal genera were still different from adult feces. The mare vaginal microbiota contributed to 24 h and 7 day microbiotas. It contained few lactobacilli, with Corynebacterium, Porphyromonas, Campylobacter and Helcococcus as the most abundant genera. In the oral mucosa, Gemella was extremely abundant. Our observations indicate that bacteria or bacterial components are present in the intestine immediately after birth, but the newborn microbiota changes rapidly.

Asunto(s)

RESUMEN

Hypoxia can lead to changes in the blood flow, nutrition and oxygenation of male germ cells and results in fertility reduction through the increase in oxidative stress. This study aims to evaluate the effect of ghrelin on testicular damage induced by hypoxia in rats. In this experimental study, 24 male rats were randomly divided into four groups: control, hypoxia, hypoxia + ghrelin and ghrelin. Animals in the control and ghrelin groups were kept in room air with 21% oxygen. The animals in the groups of hypoxia and hypoxia + ghrelin were subjected to 11% oxygen for 14 consecutive days in the hypoxia chamber. At the end of the study, the testes were removed and histological changes, as well as the apoptotic index, were investigated. Morphometrical analysis showed that hypoxia caused a significant decrease in the seminiferous tubules diameter, the germinal epithelium thickness and main Johnson's score compared to the control group (p < .05). In addition, statistical comparisons revealed a significant increase in the apoptotic index in the hypoxia group (p < .05). Administration of ghrelin + hypoxia improved the parameters mentioned above (p < .05). The results of this study indicated that ghrelin decreases the testicular damages caused by hypoxia in the rats by antioxidative activity.

RESUMEN

Several studies have been demonstrated that endometrial leukemia inhibitory factor (LIF) is important in embryo implantation. LIF is a secreted glycoprotein with a variety of biological functions including stimulation of cell proliferation, differentiation and survival that are all essential for blastocyete development and implantation. The LIF receptor activates several signaling pathways in diverse cell types, including Jak/STAT, MAPK and PI3-kinase pathways in the endometrium of fertile woman. It has been suggested that the initial lower expression of LIF in proliferative phase may be one of the causes for multiple failure of implantation. The aim of this study was to evaluate the association between maternal genotype of SNP 3951C/T LIF and in vitro fertilization and embryo transfer (IVF-ET) outcome in infertile women. This case-control study was comprised of infertile patients (n=70) and women having one healthy child as controls (n=73). Genotyping for SNP-3951C/T was performed by PCR/RFLP. Allele and genotype distribution did not differ significantly between patients and controls (P>0.05). The LIF genotype frequencies amongst the 70 cases were C/C=40%, C/T=52.8% and T/T=7.2%; the C and T allele frequencies were 66% and 34%, respectively. The LIF genotype frequencies amongst the 73 controls were C/C=45.20%, C/T=50.70% and T/T=4.1%; the C and T allele frequencies were 70% and 30%, respectively. In conclusion, the results of this study indicate that SNP 3951C/T of LIF may not be associated with IVF-ET outcome in this population. Although more studies should be considered with larger number of patients and control subjects to confirm our results.

Asunto(s)

RESUMEN

The NZ white rabbit is the animal of choice for much experimental work due to its muscular frame and similar response to human diseases, and is one of the few mammals that have had their genome sequenced. However, continuum-level computational models of rabbit muscle detailing fibre architecture are limited in the literature, especially the triceps surae complex (gastrocnemius, plantaris and soleus), which has similar biomechanics and translatable findings to the human. This study presents a geometrical model of the rabbit triceps surae informed with diffusion-weighted imaging (DWI)-based fibres. Passive rabbit-specific material properties are estimated using known muscle deformation inferred from magnetic resonance imaging data and dorsiflexion force measured with a custom-built rabbit rig and transducer. Muscle shape prediction is evaluated against a second rabbit. This study revealed that the triceps surae steady-state force post-rigor is close to post-mortem for small deformations but increases by a fixed ratio as the deformation increases and can be used to evaluate the passive behaviour of muscle. DWI fibre orientation significantly influences shape and mechanics during simulated computational muscle contraction. The presented triceps surae force and material properties may be used to inform the constitutive behaviour of continuum rabbit muscle models used to investigate pathology and musculotendon treatments that may be translated to the human condition.

Asunto(s)

RESUMEN

Although most traditional Muslim scholars condemn same-sex desires and acts, revisionist Muslim scholars have offered a more tolerant approach on this issue over the last two decades. Building on an essentialist approach to same-sex desires and acts, these scholars have argued that Islam accepts difference and diversity, including sexual diversity, as part of God's creation. Homosexuality, which in their view is an innate disposition to the same sex, is an alternative sexuality and, thus, accepted by the Qur'an and Islam. This article argues that an essentialist approach is not suitable to defend all manifestations of same-sex desires and acts, not only because it is narrow (as it excludes both bisexual Muslims and homosexual Muslims who believe that their sexual orientation is socially constructed), but also because it cannot even argue the case for the view of homosexuality as inborn. This article proposes to open up the debate beyond essentialism and constructivism, which both have their limitations, to accommodate a more inclusive and tolerant Islamic approach to same-sex desires and acts.

Asunto(s)

RESUMEN

Memory impairment is a common disorder in diabetes mellitus which is associated with hippocampal neuronal apoptosis. The present study was conducted to examine the effect of one-week intraperitoneal (ip), administration of aminoguanidine (AG) on passive avoidance learning (PAL) and Bcl-2 family gene expression in the hippocampus of rats. Sixty male rats were divided into ten groups: non-diabetic/diabetic animals with/without AG (50, 100, 200 and 400 mg/kg, ip) treatment for one week. PAL and Bcl-2 family genes were examined. AG (100 and 200 mg/kg) improved both memory and Bax, Bak, Bcl-2 and Bcl-xl deficiency significantly in diabetic rats. AG treatment also ameliorated the diabetes-induced changes in (Bcl-2+Bcl-xl)/(Bak+Bax) ratios considerably. These results propose that one-week ip administration of AG may recover the deficit cognition in diabetic rats via enhancing (Bcl-2+Bcl-xl)/(Bak+Bax) proportions (Tab. 2, Fig. 4, Ref. 55).

Asunto(s)

RESUMEN

There is no published study regarding the interaction between muscarinic receptor modulators and antinociception induced by cannabinoid receptor (CB2) agonist. The effect of pilocarpine (a muscarinic agonist) and atropine (a muscarinic antagonist) on JWH-133 (a CB2 agonist) induced analgesia in mice was studied. First the analgesic effect of JWH-133 (0.001-1 mg/Kg) or pilocarpine (2.5-20 mg/kg) or atropine (0.2-5 mg/kg) was evaluated. Subsequently, the effect of co-administration of pilocarpine (2.5 mg/kg) or atropine (5 mg/kg) and JWH-133 (0.001-1 mg/Kg) were studied too. JWH-133 and pilocarpine provoked antinociception in mice but atropine did not. Pilocarpine potentiated the analgesic effect of JWH-133 but atropine antagonized that. It can be concluded that JWH-133 induced antinociception is affected by muscarinic receptor modulators in mice.

Asunto(s)

RESUMEN

INTRODUCTION: Menopause increases the risk of cardiovascular disease in women. The aims of the present study were to evaluate the effects of swimming training on cardiac histology and expression of miR-29 and IGF-1 in the ovariectomized rats. MATERIALS AND METHODS: Thirty female Wistar rats were divided into sham and ovariectomized groups: sedentary control (OVX) and trained with 8 weeks exercise (OVX.E). On 57th day, blood was collected and used for lipid profile measurement. In addition, heart tissue was analyzed by reverse transcription-polymerase chain reaction for IGF-1 mRNA and miR-29, and studied for histopathological changes. RESULTS: Ovariectomy significantly decreased miR-29 and IGF-1 expression in the heart compared to sham animals group (p<0.05). Exercise training increased miR-29 and IGF-1 expression in the trained rats and improved histology and lipid profile compared with OVX group (p<0.05). CONCLUSION: Estrogen deficiency could lead to cardiac fibrosis through deregulation miR-29 and IGF-1 expression. The findings of the current study suggests a protective effect of exercise on heart against fibrotic changes in ovariectomized rats and support a potential preventive value of exercise in improving cardiac function after menopause.

RESUMEN

OBJECTIVE OF THE STUDY: The four RAPD systems tested in the present study have aimed at investigating DNA fingerprinting of Trichophyton mentagrophytes strains and the correlation between genotyping and antifungal susceptibility to terbinafine. PATIENTS: Twenty-nine clinical isolates of T. mentagrophytes were recovered from patients suspected of having active dermatophytosis who were referred to the laboratory of medical mycology department in Tehran university. Then, they were subjected to conventional examination by performing direct microscopic examination, culture on primary media, physiological tests. MATERIALS AND METHODS: The in vitro antifungal susceptibility of twenty-nine T. mentagrophytes isolates against terbinafine was evaluated by modified agar dilution method to determine the minimum inhibitory concentration (MIC). Twenty-one sensitive and eight resistant to terbinafine, were submitted to RAPD using 4 decamer primers (A, B, C, D) with the purpose of encountering a genetic marker to terbinafine sensibility and resistance. The UPGMA-Jaccard's correlation coefficient was used to build up dendogram that could represent clusters of similarity. According to their correlation coefficient, the samples were classified as much related (100%), moderately related (80%) and unrelated (<70%). RESULTS: All amplifications revealed distinct polymorphic bands and a total of 34 band positions was scored (0/1) for the 4 primers tested. Genetic distances between each of the isolates were calculated and cluster analysis was used to generate a dendrogram showing relationships between them. The combined dendrogram at an average similarity value of 65% grouped all strains into 2 (A, B) groups corresponding to their susceptibility reactions to terbinafine. All susceptible samples were properly grouped, but a few numbers of resistant isolates were also included. Nevertheless, further biochemical and molecular biological studies will be required to fully elucidate the point that resistance might be the result of a mutation in the gene encoding squalene epoxidase in T. mentagrophytes. CONCLUSION: This study proved efficacy of applying RAPD molecular technique to complement traditional mycological culture and drug susceptibility tests for accurate and appropriate management of recurrent dermatophytosis and highlights the need for newer antifungals that can combat the emergence of terbinafine-resistant T. mentagrophytes strains.

Asunto(s)

RESUMEN

CONTEXT: Achillea wilhelmsii C. Koch (Asteraceae) is widely used in Iranian traditional medicine. OBJECTIVE: This in vivo study evaluates the hepatoprotective role of Iranian A. wilhelmsii oils against acetaminophen-induced oxidative damages in rats. MATERIALS AND METHODS: The animals were divided into five groups: in negative control and control groups, the DMSO and 500 mg/kg acetaminophen were i.p. injected, respectively. In treatment groups, 100 and 200 mg/kg oils and 10 mg/kg BHT were given i.p. immediately after acetaminophen administration. Then, the hepatic oxidative/antioxidant parameters such as lipid peroxidation (LP), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and ferric reducing ability of plasma (FRAP) were measured in time intervals (2, 4, 8, 16, and 24 h) after administrations confirmed by histophatological consideration at 24 h. RESULTS: The results indicated that acetaminophen caused a significant elevation in SOD activity (8-24 h) and LP and FRAP levels (4 h) paralleled with significant decline in GSH level (4 and 8 h). The apparent oxidative injury was associated with evident hepatic necrosis confirmed in histological examination. The presences of A. wilhelmsii oils (100 and 200 mg/kg) with acetaminophen mitigated significantly the rise in SOD, LP, and FRAP levels and restored the GSH compared with the group treated with acetaminophen. These were confirmed by histological examination indicating the hepatic necrosis reversal by the oils. DISCUSSION AND CONCLUSION: It can be concluded that concomitant administration of A. wilhelmsii oils with acetaminophen may be useful in reversing the drug hepatotoxicity.

Asunto(s)

RESUMEN

OBJECTIVE: The present study was designed to evaluate whether microRNA-146a, as an NF-кB regulating factor and its adapter proteins (TRAF6 and IRAK1), are affected by diabetes in rat aorta. METHODS: Male Wistar rats were randomly divided into control and diabetic groups (n=6 in each). Diabetes was induced by a single injection of streptozotocin (55 mg/kg; i.p.) in 12 h fasted rats. The gene expression of microRNA-146a, NF-κB, IRAK1, and TRAF6 were determined by real time PCR. RESULTS: The expression of microRNA-146a was down-regulated in diabetic aorta when compared with the control group (p<0.05). The mRNA expression levels of NF-кB, TRAF6 and IRAK1 also increased in the diabetic rat aorta when compared with their control counterparts (p<0.01 for all comparisons). CONCLUSION: These results suggest that down-regulation of microRNA-146a may lead to derangement in NF-кB negative feedback loop, propelling the aorta toward inflammation.

Asunto(s)

RESUMEN

OBJECTIVE: Ghrelin, a 28 amino acid peptide, has diverse effects in body organs. Erythropoietin is a key mediator in increasing the red blood cells during hypoxia. Previously, we have shown that ghrelin has a polycythemic effect. In the present study, we evaluated the effect of ghrelin on erythropoietin gene expression with the aim to find out the mechanism of its effect. METHODS: Thirty two adult male Wistar rats were divided randomly into four groups. The hypoxic condition was induced by placing the rats into the hypoxic chamber with 11% oxygen for two weeks. Saline- and ghrelin-treated control rats remained in room with a regular air conditions. Erythropoietin gene expression was measured by real-time reverse transcription-polymerase chain reaction (RT-PCR). Plasma erythropoietin was measured by enzyme linked immunosorbent assay (ELISA). RESULTS: After 2-weeks of hypoxia, erythropoietin transcripts and erythropoietin plasma levels were significantly increased in hypoxic animals compared with control animals. Ghrelin treatment decreased both plasma erythropoietin and erythropoietin gene expression only in the hypoxic rats. CONCLUSIONS: Our data indicate that ghrelin might induce polycythemia through an erythropoietin-independent manner. However, to confirm this hypothesis and to find out the precise mechanism of this phenomenon further investigations are needed.

Asunto(s)

RESUMEN

BACKGROUND: Oxidative stress forms the foundation for the induction of multiple cellular pathways which can lead to the complications of diabetes mellitus that the most debilitating ones are diseases of the nervous system. In this study, we evaluated whether treadmill running could alleviate oxidative stress and apoptosis rate in the hippocampus of streptozotocin- induced diabetic rats. METHODS: Forty male Wistar rats were randomly divided into four groups (n=10): Control group (CR), exercised group (CE), diabetic group (DR) and diabetic-exercised group (DE). Diabetes was induced by injection of streptozotocin in male rats. All rats in the trained group run on a rodent motor-driven treadmill for eight weeks. At the end of eight weeks, hippocampi of animals were immediately removed on ice and kept frozen. The light supernatant was taken and stored at -80°C. They were used for determination of antioxidant enzymes and TBARs level. Index of apoptosis was detected by cell death detection ELISA Kit. RESULTS: Levels of TBARs in DR and DE groups were significantly higher than CR group. SOD and GPx activities significantly increased in CE group and decreased in DR group. CAT activity significantly decreased in DR group versus CR group. The apoptosis rate significantly increased and decreased in DR and CE groups respectively compared to CR. CONCLUSION: Exercise had beneficial effects in the diabetic exercised rats, possibly in part because of alterations in the ability to adapt to exercise-induced oxidative stress.

RESUMEN

OBJECTIVE: The present study was designed to evaluate whether long-term resveratrol administration has beneficial effects on the metabolic control and oxidative stress in diabetic rats. METHODS: Male Wistar rats were divided into four groups: normal control, diabetic control, normal treated with resveratrol, and diabetic treated with resveratrol. Diabetes was induced by injection of streptozotocin (50 mg/kg; i.p.), fifteen minutes after the administration of nicotinamide (110 mg/kg; i.p.) in 12 h fasted rats. RESULTS: Four-month oral resveratrol administration (5 mg/kg/day) significantly attenuated the elevated levels of the blood glucose, glycosylated hemoglobin, total protein, albumin, urea, creatinine, and 8-isoprostane in diabetic rats. Moreover, resveratrol administration to diabetic rats improved the reduced levels of glutathione, total antioxidant capacity, and the antioxidant enzymes activities (superoxide dismutase, glutathione peroxidase, and catalase). No significant differences were observed in the activities of plasma aminotransferases (ALT and AST) and insulin levels between diabetic rats treated with resveratrol and diabetic controls. CONCLUSION: The results suggest that chronic resveratrol administration is safe and effective, and may be considered as a beneficial therapeutic compound in diabetes.

Asunto(s)

RESUMEN

INTRODUCTION: Protein kinase C (PKC), can be activated in pulmonary arterial smooth muscle cells during hypoxia, leading to hypoxic pulmonary vasoconstriction (HPV). Studies are going on to detect the strict PKC isoform involved in the phenomenon. It has been shown that ghrelin, a 28-amino-acid peptide, may protect lungs from HPV side effects, to some extent. The aim of study was to evaluate the effect of exogenous ghrelin on PKC-ε and PKC-δ gene expression during chronic hypoxia. MATERIAL AND METHODS: Twenty-four adult male Wistar rats were divided randomly in 3 groups. Hypoxic rats with saline or ghrelin treatment were placed in a normobaric hypoxic chamber for 2 weeks. Controls remained in room air. PKC-ε and PKC-δ gene expression was measured by real-time RT-PCR. RESULTS: Morphometric analysis showed that ghrelin reversed the hypoxia induced pulmonary artery wall thickness. In hypoxic animals, there was a 2- and 4-fold increment in PKC-ε and PKC- δ gene expression, respectively. Ghrelin treatment reduced the overexpression of PKC-ε and PKC-δ to control animals' value. CONCLUSION: Ghrelin by decreasing the expression of PKC-ε and PKC-δ in hypoxic animals reduces the HPV. Although more studies are needed, it could be an honest deduction that ghrelin affects HPV in a multifunctional manner and might be used as a therapeutic agent in the future.

Asunto(s)

RESUMEN

Our objective was to study the relationships between colostral somatic cell counts (SCC, a criterion for mastitis severity at parturition) and early calf growth, blood indicators of immunity, and pre-weaning faecal and health states. Sixty-nine Holstein cows were assigned to three groups of greater (n = 21, 5051 × 10(3)), medium (n = 38, 2138 × 10(3)) and lower (n = 10, 960 × 10(3)) colostral SCC (per ml) in a completely randomized design. Calves received 2 l of colostrum on day 1, and jugular blood was sampled at birth, at 3 h after the first colostrum feeding and at 42 days of age for immunoglobulin G (IgG) measurements. Calves were fed transition milk from their dams until 3 days of age and whole milk from 4 to 60 days of age twice daily at 10% of body weight. Health status and faecal physical scores were recorded daily for 42 days. Increased colostral SCC was associated with increased serum IgG at parturition. Colostral pH increased and fat percentage decreased linearly with the rising SCC. Feeding colostrum with greater SCC was associated with reduced serum IgG concentrations at 3 h after first colostrum feeding, greater incidences of diarrhoea and compromised health status during the first 42 days of age, and reduced weaning weight gain, but had no effects on calf body length and withers height. Colostral volume and percentages of protein, lactose, solids-non-fat, total solids and IgG were comparable among groups. Results suggest a role for SCC, as an indicator of mastitis and colostral health quality, in affecting calf health. As a result of the novelty of calf health dependence on colostral SCC found, future studies to further characterize such relationships and to uncover or rule out possible mediators are required before colostral SCC could be recommended for routine on-farm use in managing dry cow and calf production.

Asunto(s)

RESUMEN

OBJECTIVES: The aim of this study was to enhance the antimicrobial efficacy of a liposomal gentamicin formulation with gallium metal (Lipo-Ga-GEN) against clinical isolates of Pseudomonas aeruginosa. METHODS: Sputum isolates of P. aeruginosa from cystic fibrosis patients were used to determine the MIC and MBC of Lipo-Ga-GEN. P. aeruginosa biofilms were formed and used to compare the minimum biofilm eradication concentration of the conventional drugs with that of Lipo-Ga-GEN. Quorum sensing (QS) molecule reduction of P. aeruginosa was determined by monitoring N-acyl homoserine lactone production using Agrobacterium tumefaciens reporter strain (A136). Viability of the cultured human lung epithelial cells (A549) was determined by Trypan Blue assay in order to assess Ga toxicity. RESULTS: MIC and MBC values indicated that gentamicin was more effective against a highly resistant strain of P. aeruginosa (PA-48913) when delivered as a Lipo-Ga-GEN formulation (256 mg/L free gentamicin versus 2 mg/L Lipo-Ga-GEN). Lipo-Ga-GEN was the only formulation that completely eradicated biofilms and blocked QS molecules at a very low concentration (0.94 mg/L gentamicin). The decrease in cell viability was less in A549 cells exposed to Lipo-Ga, suggesting that encapsulated Ga is safer. CONCLUSIONS: The results clearly indicate that the Lipo-Ga-GEN formulation is more effective than gentamicin alone in eradicating antibiotic-resistant P. aeruginosa isolates growing in a planktonic or biofilm community.

Asunto(s)

RESUMEN

Chronically administered insulin returns enhanced maximal glucose transport capacity induced by diabetes to its normal state. In this study, the direct and acute effects of insulin on glucose transport in different parts of isolated small intestine were investigated. Mucosal Fluid Transport (MFT), Mucosal Glucose Transport (MGT) and Serosal Glucose Transport (SGT) were measured in the presence and absence of insulin in averted sacs, prepared from female Wistar rats. This study shows that the presence of insulin in vitro (40 and 80 microU/mL) can reduce MGT and SGT in different segments of the small intestine (duodenum, jejunum and ileum) after 30 min whereas it had no effect on MFT. Mucosal glucose transfer rates in the duodenum, jejunum and ileum of the controls were 6.07+/-0.4, 6.34+/-0.62 and 6.43+/-0.47 mg/g tissue respectively which were significantly reduced to 3.82+/-0.93, 3.60+/-0.50 and 1.17+/-0.45 in the presence of 80 microU/mL of insulin. Serosal glucose transfer too was decreased significantly from 0.3+/-0.05, 0.57+/-0.07 and 0.43+/-.07 in the duodenum, jejunum and ileum to 0.16+/-0.03, 0.16+/-0.04 and .07+/-.02 respectively. Mucosal fluid transfer was not affected by insulin. Insulin was as effective whether it was added on the mucosal or the serosal side. The results of this study show that insulin can directly affect glucose transport in the small intestine; its physiological role must be examined. Direct effect of insulin deficiency on glucose absorption in diabetic patients may play a role in the pathophysiology of the disease.

Asunto(s)

RESUMEN

The anterograde projections of the motorcortical tongue area to the hypoglossal nucleus and neighbouring structures were studied in the rhesus monkey, squirrel monkey, saddle-back tamarin and tree shrew. Biotin dextranamine served as tracer. Direct projections into the hypoglossal nucleus were only found in the rhesus monkey and squirrel monkey. All four species, however, showed a direct projection into the dorsal and parvocellular reticular formation which in turn projects into the hypoglossal nucleus. The findings suggest a phylogenetic trend in the projections of the motorcortical tongue area from non-primate mammals via non-human primates to man in the sense that the cortico-motoneuronal connection is strengthened towards man. This might be one reason for the superior role the tongue plays in human vocal behaviour in contrast to non-human vocalization.

Asunto(s)