Giving speech a hand: gesture modulates activity in auditory cortex during speech perception

Viewing hand gestures during face-to-face communication affects speech perception and comprehension. Despite the visible role played by gesture in social interactions, relatively little is known about how the brain integrates hand gestures with co-occurring speech. Here we used functional magnetic resonance imaging (fMRI) and an ecologically valid paradigm to investigate how beat gesture-a fundamental type of hand gesture that marks speech prosody-might impact speech perception at the neural level. Subjects underwent fMRI while listening to spontaneously-produced speech accompanied by beat gesture, nonsense hand movement, or a still body; as additional control conditions, subjects also viewed beat gesture, nonsense hand movement, or a still body all presented without speech. Validating behavioral evidence that gesture affects speech perception, bilateral nonprimary auditory cortex showed greater activity when speech was accompanied by beat gesture than when speech was presented alone. Further, the left superior temporal gyrus/sulcus showed stronger activity when speech was accompanied by beat gesture than when speech was accompanied by nonsense hand movement. Finally, the right planum temporale was identified as a putative multisensory integration site for beat gesture and speech (i.e., here activity in response to speech accompanied by beat gesture was greater than the summed responses to speech alone and beat gesture alone), indicating that this area may be pivotally involved in synthesizing the rhythmic aspects of both speech and gesture. Taken together, these findings suggest a common neural substrate for processing speech and gesture, likely reflecting their joint communicative role in social interactions.     

Role of dietary polyphenols in platelet aggregation. A review of the supplementation studies

Epidemiological studies suggest that high polyphenols intake from diet is associated with reduced risk for cardiovascular diseases. Platelet aggregation is a crucial mechanism in the pathogenesis and clinical expression of coronary acute syndrome, and there is extensive evidence that antiplatelet therapy reduces cardiovascular disease risk. In this review, the available literature on the effect of polyphenols supplementation on platelet aggregation in humans or animal models has been critically analyzed, taking into consideration the different experimental protocols employed. In some studies, polyphenols supplementation did not show any effect on platelet aggregation. However, in the most of the studies, polyphenols supplementation, either as purified compounds or food extracts, showed some inhibitory effects, both in humans and in animal models. The extent of the inhibition varies in a wide range, depending on the experimental conditions used. The observed inhibitory effect of polyphenols on platelet aggregation might explain, at least in part, the epidemiological data on beneficial effect of dietary polyphenols on cardiovascular disease risk and suggests a role for polyphenols in helping to prevent cardiovascular diseases.     

Magnetic resonance spectroscopy reveals an epileptic network in juvenile myoclonic epilepsy

Purpose: To investigate the cerebral metabolic differences between patients with juvenile myoclonic epilepsy (JME) and normal controls and to evaluate to what extent these metabolic alterations reflect involvement of an epileptic network. Methods: Sixty patients with JME were submitted to multi‐voxel proton spectroscopy (1H‐MRS) at 1.5 T over medial prefrontal cortex (MPC), primary motor cortex (PMC), thalamus, striatum, posterior cingulate gyrus (PCG), and insular, parietal, and occipital cortices. We determined ratios for integral values of N‐acetyl‐aspartate (NAA) and glutamate‐glutamine (GLX) over creatine‐phosphocreatine (Cr). The control group (CTL) consisted of 30 age‐ and sex‐matched healthy volunteers. Results: The NAA/Cr ratio, a measure of neuronal injury, was reduced in PMC, MPC, and thalamus among patients. In addition, they had an altered GLX/Cr ratio, which is involved in excitatory activity, on PMC, MPC, and PCG, where it was reduced, whereas it was increased on insula and striatum. Multiple regression analysis revealed the strongest correlation between thalamus and MPC, but the thalamus was also correlated with insula, occipital cortex, and striatum among patients. Lower NAA/Cr was observed with advancing age and duration of epilepsy, regardless of frequency of seizures and antiepileptic drug therapy in thalamus and frontal cortex. Discussion: The identification of a specific network of neurochemical dysfunction in patients with JME, with diverse involvement of particular structures within the thalamocortical circuitry, suggests that cortical hyperexcitability in JME is not necessarily diffuse, supporting the knowledge that the focal/generalized distinction of epileptogenesis should be reconsidered. Furthermore, evidence is provided toward progressive neuronal dysfunction in JME.     

GROWTH HORMONE ATTENUATES MYOCARDIAL FIBROSIS IN RATS WITH CHRONIC PRESSURE OVERLOAD-INDUCED LEFT VENTRICULAR HYPERTROPHY

• 1 The role of growth hormone (GH) in cardiac remodelling and function in chronic and persistent pressure overload‐induced left ventricular hypertrophy has not been defined. The aim of the present study was to assess short‐term GH treatment on left ventricular function and remodelling in rats with chronic pressure overload‐induced hypertrophy.
• 2 Twenty‐six weeks after induction of ascending aortic stenosis (AAS), rats were treated with daily subcutaneous injections of recombinant human GH (1 mg/kg per day; AAS‐GH group) or saline (AAS‐P group) for 14 days. Sham‐operated animals served as controls. Left ventricular function was assessed by echocardiography before and after GH treatment. Myocardial fibrosis was evaluated by histological analysis.
• 3 Before GH treatment, AAS rats presented similar left ventricular function and structure. Treatment of rats with GH after the AAS procedure did not change bodyweight or heart weight, both of which were higher in the AAS groups than in the controls. After GH treatment, posterior wall shortening velocity (PWSV) was lower in the AAS‐P group than in the control group. However, in the AAS‐GH group, PWSV was between that in the control and AAS‐P groups and did not differ significantly from either group. Fractional collagen (% of total area) was significantly higher in the AAS‐P and AAS‐GH groups compared with control (10.34 ± 1.29, 4.44 ± 1.37 and 1.88 ± 0.88%, respectively; P < 0.05) and was higher still in the AAS‐P group compared with the AAS‐GH group.
• 4 The present study has shown that short‐term administration of GH to rats with chronic pressure overload‐induced left ventricular hypertrophy induces cardioprotection by attenuating myocardial fibrosis.