Thread: additional thoghts about dreaming

Regarding the % of brain matter used and such there has been alot of debate on this forum. It was generally agreed that it isn't true how people say that we use hardly any of our brains, however we use small different parts all the time.
You will need O'nus around on the forum, he can answer your questions about brain chemicals and dreaming ect.

First, I will comment about the percentage of the brain.

I find this sentence very confusing, "We only use 10% of our brains potential". The problem with this is how can you place a percentage on a potential or rate the use of the brain when you do not even know the full extent. The truth is, you only need a certain percentage of your brain to do certain tasks. You do not need to use every sense in your body to eat a burger now do you?

Yes, the hemispheres have their own individual tasks, but they are still very correlated and work in harmony. There were rumous around that they are not connected, which is very false. The hemispheres work together all the time and are connected by the corpus callosum.

To quote a text from Pierce J. Howard (PhD in Neurobiology), "We do know that the left brain is the seat of language, logic, interpretation, and arithmetic, while the right brain is the seat of geometry, nonverbal processes, visual pattern recognition (faces, lines), auditory discrimination, and spatial skills. We know that the left hemisphere governs activity on the right side of the body and the right hemisphere governs activity on the left side. We know that people of all ages inwardly exhibit measurable left-brain activity when they outardly engage in approach behaviors, cheerfulness, and other such positive emotions."

And last, the parts of the brain responsible for dream acitivity. To elucidate this, I will quote my tutorial(Click here):

Wakefulness is maintained by activity in two systems of brainstem neurons. Nerve cells that make the neurotransmitter acetylcholine stimulate the thalamus, which activates the cerebral cortex. Full wakefulness also requires cortical activation by other neurons that make monoamine neurotransmitters (MAOI's) such as norepinephrine, serotonin, and histamine. During slow wave sleep, neuron activity in both pathways slows down. During rapid eye movement sleep, the neurons using acetylcholine fire rapidly, producing a dreaming state, but the monoamine cells stop firing altogether.

The difference is supplied by three sets of nerve cells in the upper part of the brainstem: nerve cells in the locus coeruleus that contain the neurotransmitter norepinephrine; in the dorsal and median raphe groups that contain serotonin; and in the tuberomammillary cell group that contains histamine. These monoamine neurons fire most rapidly during wakefulness, but they slow down during slow wave sleep, and they stop during REM sleep.

The brainstem cell groups that control arousal are in turn regulated by two groups of nerve cells in the hypothalamus, part of the brain that controls basic body cycles. One groups of nerve cells, in the ventrolateral preoptic nucleus, contain inhibitory neurotransmitters, galanin and gamma-amino butyric acid (GABA). When the ventrolateral preoptic neurons fire, they are thought to turn off the arousal systems, causing sleep. Damage to the ventrolateral nucleus produces irreversible nsomnia.

A second group of nerve cells in the lateral hypothalamus act as an activation switch. They contain the neurotransmitters orexin and dynorphin, which provide an excitatory signal to the arousal system, particularly to the monoamine neurons. In experiments in which the gene for the neurotransmitter orexin was experimentally removed in mice, the animals became narcoleptic. Similarly, in two dog strains with naturally occurring narcolepsy, an abnormality was discovered for the gene for the type 2 orexin receptor. (I couldn't find out which chromosome or gene, though, sorry). Recent studies show that in humans with narcolepsy, the orexin levels in the brain and spinal fluid are abnormally low. Thus, orexin appears to play a critical role in activating the monoamine system, and preventing abnormal transitions, particularly into REM sleep.

Two main signals control this circuitry. First, there is homeostasis, or the body's need to seek a natural equilibrium. There is an intrinsic need for a certain amount of sleep each day. The mechanism for accumulating sleep need is not yet clear. Some people think that a chemical called adenosine may accumulate in the brain during prolonged wakefulness, and that may drive sleep homeostasis. Interestingly, the drug caffeine, which is widely used to prevent sleepiness, acts as an adenosine blocker, to prevent its effects.

To sum it up essentially: dreams are the dancing ACh within the cortex with absense of monoamine neurotransmitters.

Chemicals Involved:
(See tutorial for details)
- Acetylcholine (ACh)
- Melatonin
- Serotonin and other precursor melatonin reproducers ie. vitamin b6 (pyridoxine)

Hope I have been enlightening.

yeh that's what i was going to say

thanks again for the replies.that makes things a little clearer.far-out!! looks like i have lots of homework to do.