VVagus Nerve Stimulation (VNS) is now being used for depression, seizures and eating disorders. Although the precise mode of action of VNS is not known, researchers suggest that VNS increases seizure threshold by causing widespread release of GABA and Glycine in the brain. Reported changes in blood flow in the cerebellum, thalamus and cortex might activate inhibitory structures in the brain reducing seizure kindling. One VNS study showed mean seizure frequency to decrease by 25%. Altered synaptic activities at sites of persisting VNS-induced cerebral blood flow changes may reflect antiseizure actions.
Depression affects some 340 million people worldwide and there is a correlation between depression and the likelihood of developing seizures. VNS increases cognitive skills reflecting a reduction in depression. Areas of the brain that are affected by Vagus Nerve Stimulation include the medulla, cerebellum, parabrachial nucleus, locus ceruleus, hypothalamus, thalamus, amygdala, hippocampus and cingulated gyrus. Noradrenergic and/or serotonergic deficits, may contribute to predisposition to some epilepsies and depressions. Evidence suggests that vagus nerve stimulation exerts at least some of its anticonvulsant and antidepressant effects through its capacity to increase noradrenaline and serotonin transmission.
The vagus is responsible for keeping the larynx open for breathing and also feeds the lungs and diaphragm. Deep breathing stimulates the vagus nerve bringing balance between the parasympathetic and sympathetic nervous systems. Since a VNS device and its surgical implantation will run at nearly $30,000 it's an expensive treatment for seizure, compulsiveness and depression...breathing however does a similar job of activating the vagus nerve and it's free.
The sense of contraction and pain in the core of ones torso and neck during the heating phase prior to popping is obviously the vagus nerve making a valiant effort to counter the revving up of the pituitary-adrenal-axis, and the sympathetic nervous system. The vagus is trying to keep the emotional-memory arousal faculties of the body repressed; hence we feel this conflict as a persistent tension in our core for up to 2 years prior to awakening.
Besides breathing it is also possible to stimulate the vagus into relaxing the body-core by turning the minds eye into ones center and actively warming and purposefully letting the area go. All thoughts, emotions and phenomena are drawn into ones core as though one is an atomic karmic disposal unit. We could call this practice Melting In The Core--turning the minds eye into actively stimulating the vagus nerve into relaxing the viscera. This alleviates depression, increases coherency, lucidity, makes for a more vibrant personality and improves health and well-being.
Scientists are investigating the existence of non-genital orgasms suggesting a more pervasive orgasmic process and its role in neuroendocrine and psychological health. There are vaginocervical sensory pathways to the brain that can produce the absence of pain without loss of consciousness (analgesia), release oxytocin, and bypass the spinal cord via the vagus nerve. That is a paraplegic woman can still have cervical and G spot orgasms because the vagina is fed by the vagus nerve while the clitoris by nerves that come out of the spine. This gives weight to the necessity of sexual intercourse for maintaining healthy balance of the nervous system. Also there might be something to the validity of having sex during an awakening to help the parasympathetic nervous system to maintain its own. Orgasm has been described as a mini-seizure of the limbic system and tends to release or lessen deep limbic activity. Dr Amen noticed that depression, sadness, feelings of hopelessness, and automatic negative thoughts correlate with a hyperactive limbic area. The supplements that seem to help limbic hyperactivity best are DL-phenylalanine (DLPA), L-tyrosine, and S-Adenosyl-Methionine (SAMe).
I find it fascinating that the parasympathetic off-switch vagus turns on activating neurotransmitters in the emotional memory systems...obviously this is a big factor in the reward/punishment building of our response system. One of the contributors to the tenacity of PTSD as well no doubt, and you know they give norepinephrine blockers to trauma victims to block the vividness of their memory.
Because stimulation of the vagus nerve activates the memory centers in the brain it is apparent that sex would be good for improving memory ability. Since memory is primary to our sense of meaning and to cognition in general, it is apparent that sex has the potential of improving intelligence and quality of life through improved brain function and freedom from depression. The counter argument to this is that the endorphins produced during sex would reduce mental alertness.
Retraining the Vagus--Lie flat on your stomach with your head to one side. Progressively relax your jaw by imagining it dropping down toward your feet. You will notice that this stimulates breathing, for you get the sense of oxygen hunger. Obviously a tight jaw is tied into the neural circuits for the suspension of breath and shallow breathing. Repeating this expercise and making this jaw-contraction more conscious will help to retrain the medulla and vagus toward deeper breathing and change the setpoint of the nervous system toward greater relaxation. That is, bringing consciousness to contracted tissue helps to get rid of the inefficient fossilized tension that perpetuates itself for no good reason.