Certain published study results have found that LLLT can cause negative reactions when an inappropriate choice of light source or an inappropriate dosage is used. There is an optimal dose of light for any particular application, and in the case of red light therapy, often lower doses are found to be more effective than higher doses. Be sure to work with a qualified LLLT practitioner whenever receiving treatments, and report any side effects, including burning, swelling, dizziness, muscle weakness or nausea. Keep in mind that seeing results from red light treatments might take patience and that responsiveness is expected to vary.
Inhaled anaesthetic agents act in different ways at the level of the central nervous system. They may disrupt normal synaptic transmission by interfering with the release of neurotransmitters from pre-synaptic nerve terminal (enhance or depress excitatory or inhibitory transmission), by altering the re-uptake of neurotransmitters, by changing the binding of neurotransmitters to the post-synaptic receptor sites or by influencing the ionic conductance change that follows activation of the post-synaptic receptor by neurotransmitters. Both pre- and post-synaptic effects have been found.
Direct interaction with the neuronal plasma membrane is very likely, but indirect action via production of a second messenger also remains possible. The high correlation between lipid solubility and anaesthetic potency suggests that inhalational anaesthetic agents have a hydrophobic site of action. Inhalational agents may bind to both membrane lipids and proteins. It is not clear which of the different theories are most likely to be the main mechanism of action of inhalational anaesthetic agents.
The Meyer-Overton theory describes the correlation between lipid solubility of inhaled anaesthetics and MAC and suggests that anaesthesia occurs when a sufficient number of inhalational anaesthetic molecules dissolve in the lipid cell membrane. The Meyer-Overton theory postulates that it is the number of molecules dissolved in the lipid cell membrane, and not the type of inhalational agent, that causes anaesthesia. Combinations of different inhaled anesthetics may have additive effects at the level of the cell membrane.
Consider what would happen if, late at night, you noticed a building on fire. Hopefully, you would dial 911 or a similar emergency number. You would inform the dispatcher of the fire, and the dispatcher would, in turn, contact and "activate" a number of firemen. The firefighters would then rapidly go to work pouring water on the fire, setting up roadblocks and the like. They would also probably activate other "players", such as police and fire investigators that would come in later to try and determine the cause of the fire. Importantly, once the fire is out (or the building totally destroyed), the firemen go back to the station and to sleep.