Result Of Rebound Research Articles

Persistent irregular activity is a result of rebound and coincident detection mechanisms: A computational study

Persistent irregular activity is defined as elevated irregular neural discharges in the brain in such a way that while the average network activity displays high frequency oscillations, the participating neurons display irregular and low frequency oscillations. This type of activity is observed in many brain regions like prefrontal cortex that plays a role in working memory. Previous studies have shown that large networks with sparse connections, networks with strong noise and persistent inhibition and networks with structured synaptic connections display persistent-irregular activity. However, experimental studies show that, not all brain regions obey these assumptions. In this study we show that a small network of excitatory–inhibitory neurons with random synaptic connections can reproduce persistent-irregular activity. In particular, the model shows that less than perfect rebound pattern in excitatory cells, coincident-sensitive inhibitory cells and sparse synaptic inhibition can account for persistent-irregular activity in an excitatory–inhibitory neural network with randomly assigned synaptic connections.

The determination of land emergence from sea level observations in southeast Alaska

Sea level observations in southeast Alaska show a maximum rate of land emergence relative to the level of the sea of 3.96 cm/yr at Bartlett Cove, Glacier Bay. A conservative estimate of total maximum emergence, based on direct observations, is 154 cm from 1922 to 1960. Land emergence at a rate greater than 1.9 cm/yr is found within an area roughly bounded by Skagway, Juneau, the outer coast, and a north-south line located about half-way between the head of Glacier Bay and Yakutat. The area of emergence is reniform, with its major axis oriented in a north-south direction. Its steepest slopes lie to the south and west. The feature appears to be the result of rebound from present localized deglaciation or the combination of present localized and general post-Wisconsin deglaciation. The study is based on 28 separated series of sea level observations extending as far back as 1887 and 5 continuous series, the oldest extending back to 1919. The oldest series of observations within the 1.9 cm/yr emergent zone dates from 1902.