Photo

Tue, 18 Jun 2013 20:15:19 -0700

Photo

Tue, 18 Jun 2013 19:22:55 -0700

Photo

Tue, 18 Jun 2013 18:30:22 -0700

“Color is a matter of taste and of sensitivity.” -Eduardo Manet

Tue, 18 Jun 2013 18:24:05 -0700

“Color is a matter of taste and of sensitivity.”

-Eduardo Manet

Photo

Tue, 18 Jun 2013 18:23:40 -0700

thekhooll: Soccer ! Ross Brown. Lurzers Archive rates him...

Tue, 18 Jun 2013 18:23:32 -0700

thekhooll:

Soccer !

Ross Brown. Lurzers Archive rates him among the top 200 Advertising Photographers worldwide.

Photo

Thu, 28 Mar 2013 17:38:00 -0700

“With a new day comes new strengths and new thoughts.” -Eleanor Roosevelt

Thu, 28 Mar 2013 16:45:28 -0700

“With a new day comes new strengths and new thoughts.”

-Eleanor Roosevelt

Photo

Thu, 28 Mar 2013 15:52:53 -0700

cinoh: (via Urban Alchemy/Gordon Matta-Clark: October 30, 2009...

Wed, 27 Mar 2013 21:07:58 -0700

cinoh:

(via Urban Alchemy/Gordon Matta-Clark: October 30, 2009 - June 5, 2010)

softpyramid: Tim PughBeech Weave

Wed, 27 Mar 2013 20:15:33 -0700

softpyramid:

Tim Pugh
Beech Weave

Photo

Wed, 27 Mar 2013 19:23:02 -0700

kacper-kiec: trudne wybory / thought choices

Wed, 27 Mar 2013 18:30:24 -0700

kacper-kiec:

trudne wybory / thought choices

Photo

Wed, 27 Mar 2013 17:38:03 -0700

"Once in a golden hour, I cast to earth a seed, And up there grew a flower, That others called a..."

Wed, 27 Mar 2013 16:45:36 -0700

“Once in a golden hour,
I cast to earth a seed,
And up there grew a flower,
That others called a weed.”

- Alfred Tennyson

neurosciencestuff: Mapping blank spots in the cheeseboard...

Wed, 27 Mar 2013 15:53:05 -0700

neurosciencestuff:

Mapping blank spots in the cheeseboard maze

IST Austria Professor Jozsef Csicsvari together with collaborators succeeds in uncovering processes in which the formation of spatial memory is manifested in a map representation • Researchers investigate timescale of map formation • Inhibitory interneurons possibly involved in selection of map

During learning, novel information is transformed into memory through the processing and encoding of information in neural circuits. In a recent publication in Neuron, IST Austria Professor Jozsef Csicsvari, together with his collaborator David Dupret at the University of Oxford, and Joseph O’Neill, postdoc in Csicsvari’s group, uncovered a novel role for inhibitory interneurons in the rat hippocampus during the formation of spatial memory.

During spatial learning, space is represented in the hippocampus through plastic changes in the connections between neurons. Jozsef Csicsvari and his collaborators investigate spatial learning in rats using the cheeseboard maze apparatus. This apparatus contains many holes, some of which are selected to hide food in order to test spatial memory. During learning trials, animals learn where the rewards are located, and after a period sleep, the researchers test whether the animal can recall these reward locations. In previous work, they and others have shown that memory of space is encoded in the hippocampus through changes in the firing of excitatory pyramidal cells, the so-called “place cells”. A place cell fires when the animal arrives at a particular location. Normally, place cells always fire at the same place in an environment; however, during spatial learning the place of their firing can change to encode where the reward is found, forming memory maps.

In their new publication, the researchers investigated the timescale of map formation, showing that during spatial learning, pyramidal neuron maps representing previous and new reward locations “flicker”, with both firing patterns occurring. At first, old maps and new maps fluctuate, as the animal is unsure whether the location change is transient or long-lasting. At a later stage, the new map and so the relevant new information dominates.

The scientists also investigated the contribution of inhibitory interneuron circuits to learning. They show that these interneurons, which are extensively interconnected with pyramidal cells, change their firing rates during map formation and flickering: some interneurons fire more often when the new pyramidal map fires, while others fire less often with the new map. These changes in interneuron firing were only observed during learning, not during sleep or recall. The scientists also show that the changes in firing rate are due to map-specific changes in the connections between pyramidal cells and interneurons. When a pyramidal cell is part of a new map, the strengthening of a connection with an interneuron causes an increase in the firing of this interneuron. Conversely, when a pyramidal cell is not part of a new map, the weakening of the connection with the interneuron causes a decrease in interneuron firing rate. Both, the increase and the decrease in firing rate can be beneficial for learning, allowing the regulation of plasticity between pyramidal cells and controlling the timing in their firing.

The new research therefore shows that not only excitatory neurons modify their behaviour and exhibit plastic connection changes during learning, but also the inhibitory interneuron circuits. The researchers suggest that inhibitory interneurons could be involved in map selection – helping one map dominate and take over during learning, so that the relevant information is encoded.

Photo

Tue, 26 Mar 2013 21:02:47 -0700

Photo

Tue, 26 Mar 2013 21:02:09 -0700

Photo

Tue, 26 Mar 2013 21:02:00 -0700

"Crystals grew inside rock like arithmetic flowers."

Thu, 08 Nov 2012 20:15:22 -0800

“Crystals grew inside rock like arithmetic flowers.”

- Annie Dillard

Burning Torch

Photo

Photo

Photo

“Color is a matter of taste and of sensitivity.” -Eduardo Manet

Photo

thekhooll: Soccer ! Ross Brown. Lurzers Archive rates him...

Soccer !

Photo

“With a new day comes new strengths and new thoughts.” -Eleanor Roosevelt

Photo

cinoh: (via Urban Alchemy/Gordon Matta-Clark: October 30, 2009...

softpyramid: Tim PughBeech Weave

Photo

kacper-kiec: trudne wybory / thought choices

Photo

"Once in a golden hour, I cast to earth a seed, And up there grew a flower, That others called a..."

neurosciencestuff: Mapping blank spots in the cheeseboard...

Photo

Photo

Photo

"Crystals grew inside rock like arithmetic flowers."