Dopamine acts primarily as a neuromodulator, potentiating or attenuating synaptic transmission of classical neurotransmitters. At the level of the striatum, it stimulates dopaminergic receptors that are located near glutamatergic fronto-striatal and thalamo-striatal synapses, thus modulating information flow through fronto-striato-thalamo-frontal loops.
“Scientists have traced vulnerability to depression-like behaviors in mice to out-of-balance electrical activity inside neurons of the brain’s reward circuit and experimentally reversed it…Instead of suppressing it, researchers..boosted runaway neuronal activity even further, eventually triggering a compensatory self-stabilizing response. Once electrical balance was restored, previously susceptible animals were no longer prone to becoming withdrawn, anxious, and listless following socially stressful experiences.”
This is THE fundamental system for all behavior “seeking/craving/getting ” behavior and all business, duh.
“…dopamine may act as a filter for selecting particular inputs, and thereby exert selective effects on corticostriatal inputs that underlie various behaviors.”
- The novelty response of DA neurones habituates rapidly when a sensory stimulus is repeated in the absence of behaviourally rewarding consequences.
- A phasic DA response will emerge following the presentation of a neutral sensory stimulus that predicts a primary reward. Under these conditions the DA responses to the predicted reward gradually diminish.
- When a predicted reward is omitted, a reliable depression in the spontaneous activity of the DA neurones occurs 70-100 ms after the time of expected reward delivery. Continue reading
“People with lower levels of the brain chemical dopamine are more likely to be highly aggressive in competitive situations, a small new study indicates.
During the game, participants with lower levels of dopamine were more distracted from their attempts to win money and were more likely to show aggressive behavior,”
“Scientists at The Scripps Research Institute (TSRI) have found evidence that an emotion–related brain region called the central amygdala – whose activity promotes feelings of malaise and unhappiness – plays a major role in sustaining cocaine addiction. In experiments with rats, the TSRI researchers found signs that cocaine–induced changes in this brain system contribute to anxiety–like behavior and other unpleasant symptoms of drug withdrawal—symptoms that typically drive an addict to keep using. When the researchers blocked specific brain receptors called kappa opioid receptors in this key anxiety–mediating brain region, the rats’ signs of addiction abated.”
Social networks may inflate self-esteem, reduce self-control
Users of Facebook and other social networks should beware of allowing their self-esteem — boosted by “likes” or positive comments from close friends — to influence their behavior: It could reduce their self-control both on and offline,
“The results suggest that greater social network use is associated with:
- a higher body-mass index
- increased binge eating
- a lower credit score
- higher levels of credit-card debt
for individuals with strong ties to their social network.” Continue reading
Because reward-related neural activity often peaks transiently in response to the appearance or anticipation of motivationally-relevant stimuli, primary analyses assessed effects of interactive gameplay on reward-related mesolimbic activation during the first 2 sec following gameplay onset. Continue reading