One of the neurotransmitters playing a major role in addiction is dopamine. Many of the concepts that apply to dopamine apply to other neurotransmitters as well.As a chemical messenger, dopamine is similar to adrenaline. Dopamine affects brain processes that control movement, emotional response, and ability to experience pleasure and pain.
Regulation of dopamine plays a crucial role in our mental and physical health. Neurons containing the neurotransmitter dopamine are clustered in the midbrain in an area called the substantia nigra . In Parkinson’s disease, the dopamine- transmitting neurons in this area die. As a result, the brains of people with Parkinson’s disease contain almost no dopamine.
Increased dopamine tone during meditation-induced change of consciousness
“This is the first in vivo demonstration of an association between endogenous neurotransmitter release and conscious experience. Using 11C-raclopride PET we demonstrated increased endogenous dopamine release in the ventral striatum during Yoga Nidra meditation. Yoga Nidra is characterized by a depressed level of desire for action, associated with decreased blood flow in prefrontal, cerebellar and subcortical regions, structures thought to be organized in open loops subserving executive control. In the striatum, dopamine modulates excitatory glutamatergic synapses of the projections from the frontal cortex to striatal neurons, which in turn project back to the frontal cortex via the pallidum and ventral thalamus. The present study was designed to investigate whether endogenous dopamine release increases during loss of executive control in meditation. Participants underwent two 11C-raclopride PET scans: one while attending to speech with eyes closed, and one during active meditation. The tracer competes with endogenous dopamine for access to dopamine D2 receptors predominantly found in the basal ganglia. During meditation,11C-raclopride binding in ventral striatum decreased by 7.9%. This corresponds to a 65% increase in endogenous dopamine release. The reduced raclopride binding correlated significantly with a concomitant increase in EEG theta activity, a characteristic feature of meditation. All participants reported a decreased desire for action during meditation, along with heightened sensory imagery. The level of gratification and the depth of relaxation did not differ between the attention and meditation conditions. Here we show increased striatal dopamine release during meditation associated with the experience of reduced readiness for action. It is suggested that being in the conscious state of meditation causes a suppression of cortico-striatal glutamatergic transmission. To our knowledge this is the first time in vivo evidence has been provided for regulation of conscious states at a synaptic level.”
Oxytocin has an impact on “pro-social behaviors” and emotional responses that contribute to:
However, another review notes that the hormone does not act alone in the chemistry of love, but is “just one important component of a complex neurochemical system that allows the body to adapt to highly emotive situations.”
“After all, it is rather unlikely that any widely acting hormone or neurotransmitter will be narrowly funneled to modulate complex, high-order mental processes that are specific to social cognition,” say the authors of a 2013 paper.Another review has also sounded caution, calling for research to look more to the general effects than to the specific effects of oxytocin that are being interpreted.
Scientific research has nonetheless uncovered brain oxytocin’s specific ability to modulate social behavior, including effects on motherly care and aggression, bonding between couples, sexual behavior, social memory, and trust.
Brain oxytocin also reduces stress responses, including anxiety- and these anxiolytic effects have been demonstrated in a number of species.
One of the so-called ‘love hormone’ studies was published in 2012, and it examined oxytocin levels in new lovers versus those in single people. It found that there were high levels of the hormone in the first stages of romantic attachment, and these were sustained for six months.
As shown in the recent developments listed here, scientists are still busy testing the behavioral effects of oxytocin and its role in human emotions.
RECENT DEVELOPMENTS ABOUT OXYTOCIN’S EFFECTS ON EMOTION
Oxytocin: the monogamy hormone? This study, published in the journal PNAS in November 2013, examined brain scans of men who had received oxytocin or placebo via a nasal spray. The oxytocin was associated with activation of the men’s reward centres in their brains, and with greater feelings of attraction to their partners versus other women in photographs. This followed a very similar study in The Journal of Neuroscience in November 2012: A hormone can help keep men faithful.
High oxytocin levels “trigger oversensitivity to emotions of others.” Released in January 2014, this study inEmotion found that people receiving oxytocin nasal spray saw facial expression of emotions in others more intensely.
Oxytocin makes you feel more extroverted. This 2011 research paper in Psychopharmacology gave results from intranasal oxytocin improving self-perception in social situations, amplifying personality traits such as warmth, trust, altruism and openness.
The hormone that allows us to love may also encourage us to lie. This 2014 study found participants given oxytocin were more likely to lie for the benefit of the group.