Thalamocortical loop
Encyclopedia
Thalamocortical radiations are the fibers between the thalamus
Thalamus
The thalamus is a midline paired symmetrical structure within the brains of vertebrates, including humans. It is situated between the cerebral cortex and midbrain, both in terms of location and neurological connections...

 and the cerebral cortex
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...

.

The "thalamocortical loop" is the functional loop between these two structures. The loop consists of projections from thalamus to cortex (feedforward and driving inputs) and from cortex back to thalamus. These projections usually remain within the same sensory or motor nuclei and cortex areas. The loops are involved in the production of sleep spindles, absence seizures, and the control of the propagation of sensory information.

Evolutionary significance

Computational neuroscientists are particularly interested in thalamocortical loops because they represent a structure that is disproportionally larger in humans than other mammals (when body size is taken into account) and thus may make a significant contribution to humans' special cognitive abilities.

Clinical significance

Thalamocortical Oscillations are constantly working in a normal human brain and when disrupted cause Petit Mal Seizures or Absence Seizures
Absence seizure
Absence seizures are one of several kinds of seizures. These seizures are sometimes referred to as petit mal seizures ....

 where the affected will stare into space and obtain a momentary lapse of consciousness. This is a form of Epilepsy
Epilepsy
Epilepsy is a common chronic neurological disorder characterized by seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or hypersynchronous neuronal activity in the brain.About 50 million people worldwide have epilepsy, and nearly two out of every three new cases...

where depending on the person the seizure can force purposeless bodily jerks and/or eye twitches which can differ from 10 times a day to 100.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK