Long-term potentiation (l.t.p.) was studied in area CA1 of rat hippocampal slices during development at post-natal days 1-8, 15 and 60. Tetanic stimulation at 100 Hz for 1 s was delivered to the fibres in stratum radiatum and the time course of potentiation was recorded in stratum pyramidale for 20 min after tetanus. L.t.p. was measured at 20 min post-tetanus as an increase in the amplitude of ...

Hsu, Fu-Chun and Sheryl S. Smith. Progesterone withdrawal reduces paired-pulse inhibition in rat hippocampus: dependence on GABAA receptor 4 subunit upregulation. J Neurophysiol 89: 186–198, 2003; 10.1152/jn.00195.2002. Withdrawal from the endogenous steroid progesterone (P) after chronic administration increases anxiety and seizure susceptibility via declining levels of its potent GABA-modulat...

The main excitatory pathway of the hippocampal formation is controlled by a network of morphologically distinct populations of GABAergic interneurons. Here we describe a novel type of GABAergic interneuron located in the outer molecular layer (OML) of the rat dentate gyrus with a long-range forward projection from the dentate gyrus to the subiculum across the hippocampal fissure. OML interneuro...

BACKGROUND The positive correlation between therapeutic exercise and memory recovery in cases of ischemia has been extensively studied; however, long-term exercise begun after ischemic neuronal death as a chronic neurorestorative strategy has not yet been thoroughly examined. OBJECTIVE The purpose of this study is to investigate possible mechanisms by which exercise ameliorates ischemia-induc...

The primary function of the skin is to act as a barrier against unwanted influences from the environment. The barrier function of the skin is located in the superficial of the skin, the stratum corneum. The stratum corneum consists of dead cells filled with keratin and water, which are embedded in lipid regions. The lipid regions are the only continuous structure in the stratum corneum. For thi...

The distributions of proteins and protein-bound sulphur have been studied by X-ray emission microanalysis in the plantar epidermis of six albino rats. Plantar skin was fixed in 10% formaldehyde for 24 h and 5-/4 paraffin sections obtained. Discrete and continuous measurements of the relative concentrations (mass/unit area) of proteins and sulphur were made along lines of scan perpendicular to t...

We investigated whether heptanol and other long-chain alcohols that are known to block gap junctions interfere with the generation or the propagation of spreading depression (SD). Waves of SD were triggered by micro-injection of concentrated KCl solution in stratum (s.) radiatum of CA1 of rat hippocampal tissue slices. DC-coupled recordings of extracellular potential (V0) were made at the injec...

The main function of the skin is to protect the body against exogenous substances. The skin barrier is located in the outermost layer of the skin, the stratum corneum. This layer consists of keratin enriched cells embedded in lipid lamellae. These lamellae form the main barrier for diffusion of substances through the skin. In diseased skin the barrier function is often impaired. For a full unde...

Under conditions of increased excitability, such as application of the K(+) channel blocker 4-aminopyridine (4-AP, 100 microM), interneurons in the hippocampal slice show an additional form of synchronized activity that is distinct from the ictal and interictal epileptiform activity induced by these manipulations. In principal neurons, i.e., pyramidal and granule cells, this synchronized intern...

The mammalian hippocampus expresses highly organized patterns of neuronal activity which form a neuronal correlate of spatial memories. These memory-encoding neuronal ensembles form on top of different network oscillations which entrain neurons in a state- and experience-dependent manner. The mechanisms underlying activation, timing and selection of participating neurons are incompletely unders...