Spreading depression and evoked potentials recorded in the somatosensory cortex of the rat

Cortical spreading depression (CSD) is associated with changes in the caliber of surface blood vessels; others have described it as a phenomenon which arises spontaneously and repetitively following acute cortical injury in animals, including both focal ischemia and trauma, while yet other researchers consider it to be an electrophysiological substrate of migraine aura, which may trigger headache. Our group is involved in research into both migraine and ischemia-induced pathophysiological states. It therefore appeared reasonable to include the study of CSD in the methodological repertoire utilized in our laboratory. We introduced two models of CSD induction: CSD evoked during continuous topical KCl application and CSD induced through a single KCl microinjection into the cortical tissue. This paper describes details of these two methods and of basic parameters of CSDs

Variability of leaf growth characteristics in the canopy of sessile oak and Austrian oak

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Temporal disparity of action potentials triggered in axon initial segments and distal axons in the neocortex

Neural population activity determines the timing of synaptic inputs, which arrive to dendrites, cell bodies, and axon initial segments (AISs) of cortical neurons. Action potential initiation in the AIS (AIS-APs) is driven by input integration, and the phase preference of AIS-APs during network oscillations is characteristic to cell classes. Distal regions of cortical axons do not receive synaptic inputs, yet experimental induction protocols can trigger retroaxonal action potentials (RA-APs) in axons distal from the soma. We report spontaneously occurring RA-APs in human and rodent cortical interneurons that appear uncorrelated to inputs and population activity. Network-linked triggering of AIS-APs versus input-independent timing of RA-APs of the same interneurons results in disparate temporal contribution of a single cell to in vivo network operation through perisomatic and distal axonal firing

Effects of supplemental UV-B radiation on photosynthesis performance and UV-B absorbing compounds in leaves of two oak species

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Predominantly linear summation of metabotropic postsynaptic potentials follows coactivation of neurogliaform interneurons

Summation of ionotropic receptor-mediated responses is critical in neuronal computation by shaping input-output characteristics of neurons. However, arithmetics of summation for metabotropic signals are not known. We characterized the combined ionotropic and metabotropic output of neocortical neurogliaform cells (NGFCs) using electrophysiological and anatomical methods in the rat cerebral cortex. These experiments revealed that GABA receptors are activated outside release sites and confirmed coactivation of putative NGFCs in superficial cortical layers in vivo. Triple recordings from presynaptic NGFCs converging to a postsynaptic neuron revealed sublinear summation of ionotropic GABA(A) responses and linear summation of metabotropic GABA(B) responses. Based on a model combining properties of volume transmission and distributions of all NGFC axon terminals, we predict that in 83% of cases one or two NGFCs can provide input to a point in the neuropil. We suggest that interactions of metabotropic GABAergic responses remain linear even if most superficial layer interneurons specialized to recruit GABA(B) receptors are simultaneously active

Acetyl-l-carnitine normalizes the impaired long-term potentiation and spine density in a rat model of global ischemia

Aim: The aim of this study was to enhance the knowledge regarding actors and intentions in the development process of a mobile phone platform for self-management of hypertension. Methods: Our research approach was a 14-month longitudinal “real-time ethnography” method of description and analysis. Data were collected through focus groups with patients and providers, patient interviews, and design meetings with researchers and experts. The analysis was informed by the concepts of actors and inscriptions in actor-network theory (ANT). Results: Our study showed that laypersons, scientific actors, as well as technology itself, might influence development processes of support for self-management of hypertension. The intentions were inscribed into the technology design as well as the models of learning and treatment. Conclusions: The study highlighted important aspects of how actors and intentions feature in the development of the mobile phone platform to support self-management of hypertension. The study indicated the multifacetedness of the participating actors, including the prominent role of technology. The concrete results of such processes included questions in the self-report system, learning and treatment models