Structure and function of the hippocampal CA3 module.

The hippocampal formation is crucial for learning and memory, with submodule CA3 thought to be the substrate of pattern completion. However, the underlying synaptic and computational mechanisms of this network are not well understood. Here, we perform circuit reconstruction of a CA3 module using three dimensional (3D) electron microscopy data and combine this with functional connectivity recordings and computational simulations to determine possible CA3 network mechanisms.

Generation of Sharp Wave-Ripple Events by Disinhibition.

Sharp wave-ripple complexes (SWRs) are hippocampal network phenomena involved in memory consolidation. To date, the mechanisms underlying their occurrence remain obscure. Here, we show how the interactions between pyramidal cells, parvalbumin-positive (PV) basket cells, and an unidentified class of anti-SWR interneurons can contribute to the initiation and termination of SWRs.

Intermittency in the Hodgkin-Huxley model.

We show that action potentials in the Hodgkin-Huxley neuron model result from a type I intermittency phenomenon that occurs in the proximity of a saddle-node bifurcation of limit cycles. For the Hodgkin-Huxley spatially extended model, describing propagation of action potential along axons, we show the existence of type I intermittency and a new type of chaotic intermittency, as well as space propagating regular and chaotic diffusion waves. Chaotic intermittency occurs in the transition from a turbulent regime to the resting regime of the transmembrane potential and is characterised by the existence of a sequence of action potential spikes occurring at irregular time intervals.

Latest QSAR study of adenosine Α₂Β receptor affinity of xanthines and deazaxanthines.

Adenosine, a widespread and endogenous nucleoside that acts as a powerful neuromodulator in the nervous system, is a promising therapeutic target in a wide range of conditions. The structural similarity between xanthine derivatives and neurotransmitter adenosine has led to the derivatives of the heterocyclic ring being among the most abundant chemical classes of ligand antagonists of adenosine receptor subtypes. Small changes in the xanthine scaffold have resulted in a wide array of adenosine receptor antagonists.