Expectation-induced modulation of metastable activity underlies faster coding of sensory stimuli.

Sensory stimuli can be recognized more rapidly when they are expected. This phenomenon depends on expectation affecting the cortical processing of sensory information. However, the mechanisms responsible for the effects of expectation on sensory circuits remain elusive. In the present study, we report a novel computational mechanism underlying the expectation-dependent acceleration of coding observed in the gustatory cortex of alert rats. We use a recurrent spiking network model with a clustered architecture capturing essential features of cortical activity, such as its intrinsically generated metastable dynamics. Relying on network theory and computer simulations, we propose that expectation exerts its function by modulating the intrinsically generated dynamics preceding taste delivery. Our model's predictions were confirmed in the experimental data, demonstrating how the modulation of ongoing activity can shape sensory coding. Altogether, these results provide a biologically plausible theory of expectation and ascribe an alternative functional role to intrinsically generated, metastable activity.

Lack of evidence for monosomy 1p36 in patients with Prader-Willi-like phenotype.

Monosomy 1p36 is the most common subtelomeric microdeletion syndrome with an incidence rate estimated to be 1 in 5000 births. A hypothesis of a similarity between patients with 1p36 deletion and those with Prader-Willi syndrome and the existence of two different phenotypes for 1p36 microdeletion has been suggested. The main objective of the present study was to determine the existence of 1p36 microdeletion in a sample of patients with mental retardation, obesity and hyperphagia who tested negative by the methylation test for Prader-Willi syndrome. Sixteen patients (7 females, 9 males), 16-26 years old, were evaluated with high-resolution cytogenetic analysis at 550-850 band levels and with 11 polymorphic microsatellite markers located in the 1p36 region. All patients had normal cytogenetic and molecular results. The results obtained by high-resolution cytogenetic methodology were confirmed by the molecular analyses. We did not detect a 1p36 microdeletion in 16 subjects with the Prader-Willi-like phenotype, which reinforces that no correlation seems to exist between Prader-Willi-like phenotype and the 1p36 microdeletion syndrome.

Lack of evidence for monosomy 1p36 in patients with Prader-Willi-like phenotype

Monosomy 1p36 is the most common subtelomeric microdeletion syndrome with an incidence rate estimated to be 1 in 5000 births. A hypothesis of a similarity between patients with 1p36 deletion and those with Prader-Willi syndrome and the existence of two different phenotypes for 1p36 microdeletion has been suggested. The main objective of the present study was to determine the existence of 1p36 microdeletion in a sample of patients with mental retardation, obesity and hyperphagia who tested negative by the methylation test for Prader-Willi syndrome. Sixteen patients (7 females, 9 males), 16-26 years old, were evaluated with high-resolution cytogenetic analysis at 550-850 band levels and with 11 polymorphic microsatellite markers located in the 1p36 region. All patients had normal cytogenetic and molecular results. The results obtained by high-resolution cytogenetic methodology were confirmed by the molecular analyses. We did not detect a 1p36 microdeletion in 16 subjects with the Prader-Willi-like phenotype, which reinforces that no correlation seems to exist between Prader-Willi-like phenotype and the 1p36 microdeletion syndrome.

Reconstruction of the health status in a past human population: the Iron Age necropolis of Monte Bibele (Bologna, Italy).

This paper examines the condition of health of an iron age population from Monte Bibele (Bologna, Italy). The vertebral spine is the site most frequently affected by disease: cleft atlas, spina bifida of the sacrum, sacralization of the 5th lumbar spine, arthrosis. Arthrosis is also present in the hip, elbow, shoulder and knee. Fractures are common. Periostitis and osteoporosis and a probable case of acromegaly are present. The majority of the pathologic changes observed in the population of Monte Bibele appears to be related to senescence or to occupational causes.

[Erythrocyte Li/Na countertransport and correlated variables in a randomized sample of population]. / Il controtrasporto Li/Na eritrocitario e le variabili ad esso correlate in un campione randomizzato di popolazione.

A genetically determined alteration of the cell membrane sodium metabolism may play a role in the pathogenesis of essential hypertension. The most consistent finding in patients with essential hypertension is an increased red blood cell Li/Na exchange (countertransport). It is genetically determined but it is also associated to potentially confounding variables (body weight, race, age and so on). The present study investigates the relationship between red cell Li/Na countertransport and various potentially confounding variables in a random sample of the population. It shows that this membrane cation transport system is increased in males compared to females and significantly correlated to body mass index in males and to blood pressure, alcohol consumption and, negatively, to urinary calcium excretion in females. Since body weight and alcohol consumption are correlated to blood pressure in several epidemiological studies, it can be hypothesized that they influence blood pressure control through an alteration of the cell membrane sodium transport.

Electrocardiographic findings in hypertensive patients of a population sample. Role of sex, age, and antihypertensive treatment.

During the initial phase of the World Health Organization (WHO) "Community Control Program of Hypertension" in Italy, 1190 subjects with high blood pressure derived from a general population random sample (5856 people of both sexes, aged 20 to 64 years) were enrolled in a hypertension register. At the registration visit (RV), each of them gave case history details and underwent a complete clinical examination, blood and urine tests, and a standard 12-lead electrocardiogram (ECG). All the ECGs were read by a single coder, using the second version of the Minnesota Code (MC). We calculated the prevalence of electrocardiographic codes according to sex, age, and the state of antihypertensive treatment. The overall prevalence of electrocardiographic abnormalities (i.e., all codes except 1:0 and isolated 9:4) was 40.8% with a slightly higher prevalence in males than in females: 42.4% versus 39.4%. Codes related to left ventricular hypertrophy (LVH) (3:1 or 3:3) were also more frequent in males (21.2%) than in females (14.5%) but not those related to ischemia (4:1-4:3 or 5:1-5:3). In fact, group 4 codes were present in 4.0% of males and 16.1% of females; group 5 codes, in 5.7% of males and 18.1% of females. Abnormal codes generally increased with increasing age, but those related to LVH did not follow this general rule in males. In fact, in the age class 20-29 years, codes 3:1 were found in 11.1% and codes 3:3 in 17.5% of the subjects, whereas the corresponding frequencies in the oldest age group (60-64 years) were 15.2% and 12.4%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

[Electrocardiographic changes in a cohort of hypertensive patients in a community intervention program]. / Modificazioni elettrocardiografiche in una coorte di ipertesi durante un programma di intervento su base comunitaria.

A pilot project for the control of hypertension in the Community was carried out in Italy as a part of the WHO Programme "Community Control of Hypertension". 1190 subjects identified as hypertensive (BP greater than or equal to 160 and/or 95 mmHg at two subsequent measurements, or under treatment) during the screening of a random sample of the population between 20 and 64 years in the District of Camposampiero (Padova) were enrolled in a Hypertension Register during a subsequent visit (Registration Visit: VR) carried out two months after the screening. In the following 5 years they were recalled about once a year at a Hypertension Clinic for a complete visit (VA). On both the VR and the VAs a resting electrocardiogram (ECG) was recorded and subsequently assessed according to the Minnesota Code (MC). Out of the 1190 registered hypertensive subjects, 872 (400 males and 472 females) participated in the last VA visit after 5 years, which corresponds to an overall participation rate of 69.4% in males (M) and 76.9% in females (F). Among subjects with normal and abnormal ECG at the VR, the participation rates at the last VA were, respectively, 67.9 and 71.5% in M (not significant difference); 80.0% and 70.8% in F (significant difference: P less than 0.001). Between the VR and the last VA the mean BP values of the 872 subjects investigated decreased from 162. 9/102.2 mmHg to 148. 6/90.4 mmHg in M and from 168. 7/102.2 mmHg to 155. 3/91.7 mmHg in F. The rate of abnormal ECGs increased from 44.0% to 50.3% in M and from 36.4% to 47.9% in F, involving most single items and all the classes of the MC with the exception of classes 8 and 9. The items which diminished generally had a rather low prevalence or were those indicating minor abnormalities. The apparent regression of some pathological patterns could actually be accounted for by a shift towards more severe abnormalities. The most remarkable changes occurred in codes indicating respectively left ventricular hypertrophy (3: 1 or 3: 3) and myocardial ischaemia (4: 1-3 or 5: 1-3 or 7: 1).(ABSTRACT TRUNCATED AT 400 WORDS)