Pigeon as a model to study peripheral projections from the horizontal semicircular canal vestibular apparatus to a brainstem target immunoreactive for AMPA

ABSTRACT Purpose: To evaluate whether the pigeon (Columba livia) is a good model for evaluating the vestibular system involved with postural maintenance during movement. Methods: This study maps the brainstem targets of the horizontal ampullary inputs from the vestibular periphery of the pigeon. We used biotin dextran amine (BDA) injection in horizontal semicircular canal (HSCC), immunohistochemistry for GluR2/3 and GluR4 AMPA and computerized histomorphology reconstruction. Results: Our results show the same distribution pattern with ipsilateral projections to vestibular nuclear complex (VNC) from the HSCC, with the majority of labeled fibers being, long, thin, with few varicosities and many ramifications. Horizontal semicircular canal projections achieve neurons belonging to all nuclei of the VNC with exception of dorsal portion of lateral vestibular nucleus and this area express GluR2/3 and GluR4 AMPA receptors reinforcing the idea of glutamate participation in these connections. Conclusions: Pigeon is an appropriated experimental model to study of projections of HSCC and reinforcing the information that the vestibular system has strong relation with the fast responses necessary for postural control. Moreover, its phylogenetic organization apparently conservation, also seems to be a fundamental characteristic for vertebrates.

Thermodynamic properties of Anacardium humile St. Hil. (cajuzinho-do-cerrado) achenes / Propriedades termodinâmicas de aquênios de Anacardium humile St. Hil.

The cajuzinho-do-cerrado is a native species of the cerrado of great potential of use and is threatened of extinction. The aim of this study was to determine and evaluate the thermodynamic properties of Anacardium humile St. Hil. achenes from the different hygroscopic equilibrium points according to the moisture content. To obtain the isotherms, the indirect static method was used at temperatures of 10, 20, 30 and 40 C and for moisture contents of 13.4, 11.1, 8.7 and 5.3% dry basis (db). The Copace model was used to describe the hygroscopic equilibrium of the achenes. The thermodynamic properties are influenced by the moisture content because the latent heat of vaporization of the water of the achenes increases with the decrease in the equilibrium moisture content, varying between 3,035.63 and 2,510.80 kJ kg-1 for moisture contents of 4.51 to 13.4% db, respectively. The differential enthalpy and entropy are closely related to the moisture content of the achenes. The isokinetic temperature of 304.67 K denotes the linear chemical compensation between the differential enthalpy and entropy of the Anacardium humile St. Hil. achenes, and the desorption process is controlled by enthalpy.(AU)

O cajuzinho-do-cerrado é uma espécie nativa do cerrado de grande potencial de uso e encontra-se ameaçada de extinção. Objetivou-se determinar e avaliar as propriedades termodinâmicas para diferentes teores de água de equilíbrio higroscópico dos aquênios de cajuzinho-do-cerrado. Para obtenção das isotermas utilizou-se o método estático indireto nas temperaturas de 10, 20, 30 e 40 C e teores de água de 13,4; 11,1; 8,7; 5,3% base seca (b.s.). O modelo de Copace foi utilizado para descrever o equilíbrio higroscópico dos aquênios. As propriedades termodinâmicas são influenciadas pelo teor de água, uma vez que o calor latente de vaporização da água dos aquênios aumenta com o decréscimo do teor de água de equilíbrio, variando entre 3.035,63 e 2.510,80 kJ kg-1 para os teores de água de 4,51 a 13,4% b.s., respectivamente. A entalpia e entropia diferencial estão intimamente conexas ao teor de água dos aquênios. A temperatura isocinética de 304,67 K denota a compensação química linear entre a entalpia e a entropia diferenciais dos aquênios de cajuzinho-do-cerrado, sendo o processo de dessorção controlado pela entalpia.(AU)

Thermodynamic properties of Anacardium humile St. Hil. (cajuzinho-do-cerrado) achenes / Propriedades termodinâmicas de aquênios de Anacardium humile St. Hil

The cajuzinho-do-cerrado is a native species of the cerrado of great potential of use and is threatened of extinction. The aim of this study was to determine and evaluate the thermodynamic properties of Anacardium humile St. Hil. achenes from the different hygroscopic equilibrium points according to the moisture content. To obtain the isotherms, the indirect static method was used at temperatures of 10, 20, 30 and 40 C and for moisture contents of 13.4, 11.1, 8.7 and 5.3% dry basis (db). The Copace model was used to describe the hygroscopic equilibrium of the achenes. The thermodynamic properties are influenced by the moisture content because the latent heat of vaporization of the water of the achenes increases with the decrease in the equilibrium moisture content, varying between 3,035.63 and 2,510.80 kJ kg-1 for moisture contents of 4.51 to 13.4% db, respectively. The differential enthalpy and entropy are closely related to the moisture content of the achenes. The isokinetic temperature of 304.67 K denotes the linear chemical compensation between the differential enthalpy and entropy of the Anacardium humile St. Hil. achenes, and the desorption process is controlled by enthalpy.

O cajuzinho-do-cerrado é uma espécie nativa do cerrado de grande potencial de uso e encontra-se ameaçada de extinção. Objetivou-se determinar e avaliar as propriedades termodinâmicas para diferentes teores de água de equilíbrio higroscópico dos aquênios de cajuzinho-do-cerrado. Para obtenção das isotermas utilizou-se o método estático indireto nas temperaturas de 10, 20, 30 e 40 C e teores de água de 13,4; 11,1; 8,7; 5,3% base seca (b.s.). O modelo de Copace foi utilizado para descrever o equilíbrio higroscópico dos aquênios. As propriedades termodinâmicas são influenciadas pelo teor de água, uma vez que o calor latente de vaporização da água dos aquênios aumenta com o decréscimo do teor de água de equilíbrio, variando entre 3.035,63 e 2.510,80 kJ kg-1 para os teores de água de 4,51 a 13,4% b.s., respectivamente. A entalpia e entropia diferencial estão intimamente conexas ao teor de água dos aquênios. A temperatura isocinética de 304,67 K denota a compensação química linear entre a entalpia e a entropia diferenciais dos aquênios de cajuzinho-do-cerrado, sendo o processo de dessorção controlado pela entalpia.