Using multiunit recording of action potentials from the whole nerve with the aid of external perfusion, we investigated the effects of dopamine (DOP) agonists that are involved in modulatory actions on synaptic transmission in the isolated labyrinth preparations of frogs. The external application of DOP (0.1–1 mM), the D₁ agonist chloro-APB hydrobromide (CAPB, 50–100 μM) and the D₂ agonist quinerolane (QUI, 50–100 μM) induced a dose-dependent and reversible decline in the resting discharge frequency. In this concentration range, the potency of applied CAPB considerably exceeded that of QUI. AMPA, NMDA and ACPD responses were inhibited by the D₁ and D₂ agonists, implicating both subtypes of DOP receptors in the modulation of both ionotropic and metabotropic glutamate receptors. The inhibitory action of the DOP agonists on L-glutamate responses persisted in a high Mg²⁺ solution in conditions of selective activation of the postsynaptic membrane. The results obtained suggest that DOP may interact with both D₁ and D₂ receptor subtypes, most likely located postsynaptically on the afferent nerve fibers. This dopaminergic control mechanism may result in the reduction of the activated firing rate, thus preventing over-excitation and excitotoxic injury of the afferent dendrites after the external application of L-glutamate and excessive receptor stimulation.

An emerging interest regarding nanoparticles (NPs) concerns their potential immunomodulatory and pro-inflammatory activities, as well as their impact in the circulatory system. These biological activities of NPs can be related to the intensity and type of the responses, which can raise concerns about adverse side effects and limit the biomedical applicability of these nanomaterials. Therefore, the purpose of this study was to investigate the impact of a library of cationic cellulose nanocrystals (CNCs) in the human blood and endothelial cells using cell-based assays. First, we evaluated whether the cationic CNCs would cause hemolysis and aggregation or alteration on the morphology of red blood cells (RBC). We observed that although these nanomaterials did not alter RBC morphology or cause aggregation, at 24 h exposure, a mild hemolysis was detected mainly with unmodified CNCs. Then, we analyzed the effect of various concentrations of CNCs on the cell viability of human umbilical vein endothelial cells (HUVECs) in a time-dependent manner. None of the cationic CNCs caused a dose-response decrease in the cell viability of HUVEC at 24 h or 48 h of exposure. The findings of this study, together with the immunomodulatory properties of these cationic CNCs previously published, support the development of engineered cationic CNCs for biomedical applications, in particular as vaccine nanoadjuvants.

The possibility of the utilization of the galvanic skin response (GSR) as a test for the analysis of compensatory processes under the conditions of natural compensation and with the use of functional biofeedback was studied in experiments on cats anesthetized with chloralose and immobilized with flaxedil, as well as in clinical conditions in healthy children and children suffering from childhood cerebral palsy (CCP). It was demonstrated in this study that the habituation of the GSR is disturbed in the case of unilateral brain trauma. These differences level out a year after the brain trauma. When functional biofeedback is used to accelerate habituation processes of a compensatory character, the GSR of the right and left sides of the body equalize and approximate that observed in healthy children. This study is yet another confirmation of the advantage of functional biofeedback as compared with traditional treatment methods. The data obtained also make it possible to believe that the habituation of the GSR may be useful not only for the analysis of the depth and level of the injury of nerve tissue, but for the objective assessment of compensatory restorative processes as well.