Ketamine alters oscillatory coupling in the hoppocampus

Recent studies show that higher order oscillatory interactions such as cross-frequency coupling are important for brain functions that are impaired in schizophrenia, including perception, attention and memory. Here we investigated the dynamics of oscillatory coupling in the hippocampus of awake rats upon NMDA receptor blockade by ketamine, a pharmacological model of schizophrenia. Ketamine (25, 50 and 75 mg/kg i.p.) increased gamma and high-frequency oscillations (HFO) in all depths of the CA1-dentate axis, while theta power changes depended on anatomical location and were independent of a transient increase of delta oscillations. Phase coherence of gamma and HFO increased across hippocampal layers. Phase-amplitude coupling between theta and fast oscillations was markedly altered in a dose-dependent manner: ketamine increased hippocampal theta-HFO coupling at all doses, while theta-gamma coupling increased at the lowest dose and was disrupted at the highest dose. Our results demonstrate that ketamine alters network interactions that underlie cognitively relevant theta-gamma coupling.

Local Field Potentials in the Gustatory Cortex Carry Taste Information

It has been recently shownthat localfield potentials (LFPs)fromthe auditory and visual cortices carry information about sensory stimuli, but whether this is a universal property of sensory cortices remains to be determined. Moreover, little is known about the temporal dynamics of sensory information contained in LFPs following stimulus onset. Here we investigated the time course of the amount of stimulus information in LFPs and spikes from the gustatory cortex of awake rats subjected to tastants and water delivery on the tongue. We found that the phase and amplitude of multiple LFP frequencies carry information about stimuli, which have specific time courses after stimulus delivery. The information carried by LFP phase and amplitude was independent within frequency bands, since the joint information exhibited neither synergy nor redundancy. Tastant information in LFPs was also independent and had a different time course from the information carried by spikes. These findings support the hypothesis that the brain uses different frequency channels to dynamically code for multiple features of a stimulus.

O uso do móbile marketing como estratégia de fidelização de clientes :um estudo e empresas do setor de comércio e serviços em natal-RN

This study aims to understand the effects of the mobile marketing use as a relationships tool for companies that operate locally, because of the lack of information about this new marketing tool, as well as the scarcity of studies in this area. This is an exploratory and qualitatively study, based on primary sources, raised through books, articles in the marketing area and the telecommunications industry organs as well as secondary sources. With the purpose to look into the issue, a semi-structured interview is made with the companies managers of the sectors of trade and services in Natal-RN. The advances in technology allow an important discussion focused on the marketing in the new communication technologies scenario. It appears that the mobile marketing adoption and use by local companies is already a reality and companies are awake to changes and technological innovations accessible, especially the mobile telephony as well as convergence with other media. There is, however, that the use of technologies offered by mobile marketing is still limited to the sending of text messages (SMS), despite the numerous possibilities of it use. Moreover, the results obtained with mobile marketing use show that companies can identify them, but there is no effective monitoring in quantity and financial terms. Only affect sales growth and support for progress in loyalty with customers. It shows up that the mentality of not measuring the results still in the plan of changes and technological innovations. The data allow saying that the mobile marketing is a reality, however has not yet signed as a tool for carrying out campaigns and marketing tool for loyalty of customers, despite presenting a wide range of possibilities to streamline and make more effective the marketing businesses process