Tissue layers

Usage examples of membranes.

Where they differ is in the unique properties of their cell membranes, for the nerve cell membrane is excitable - which means that in response to a signal, such as a small local fluctuation in ion concentration across the membrane, it can rapidly become permeable to the ions outside it.

They can be measured biochemically, in terms of a cellular cascade of processes which begins with the opening of ion channels in the synaptic membranes and proceeds by way of complex intracellular signals to the synthesis of new proteins which, inserted into the synaptic and dendritic membranes, are responsible for these morphological changes.

So if one group of chicks is making more nerve cell membrane, on average, than the chicks of another group, there will be more of the injected radioactive sugar in its membranes at the end of two hours.

The membranes of course contain both the proteins and the enzyme that phosphorylates them, protein kinase C.

In the hours that follow, these glycoproteins are inserted into the synaptic membranes, increasing the number of dendritic spines, and the synaptic contact areas in both left IMHV and left and right LPO.

Upon contact, the cells writhed in a time-slowed chaotic reflex as their structures were torn, their electrically balanced membranes thrown into a confused, black-limned boil that disappeared within the fog.

They could sense the charismata only through the mucous membranes of their noses and mouths.

All I need is to have a way of separating the various brain regions, purifying the membranes and measuring how much sugar has gone into them.

If I then measure much radioactivity is in the membranes - a relatively straightforward task with modern equipment - I shall be able to calculate how much sugar has been built into them.

By selecting the membranes from different brain regions, and by choosing two times to make this measurement, one beginning just after training and one five hours later, I shall be able to see in which parts of the brain the changes occur - if they do - and how long any differences between the groups last.

All the brain tissue metabolic processes, the incorporation of the radioactive sugar membranes, the post-mortem decay and dissolution of all have been halted indefinitely by the freezing.

It is a universal property of living cells that their external cell membranes are electrically charged.

If radioactive ATP is added to a tiny sample of the membranes, and incubated together for a few seconds in a miniature test-tube, the membrane proteins become both phosphorylated and radioactive.

To be precise, the synapse is the site where presynaptic terminal and postsynaptic membrane are in close contact, recognizable in the photograph as characteristic dark, thick regions where the presynaptic and postsynaptic membranes virtually - but not quite - touch.

With bald sloping brows and saggy eyes rimmed underneath by drooping blue membranes, they were half a head taller than a typical human and much heavier.