Dopaminergic pathways

Through separate connections to the prefrontal cortex (mesocortical) and ventral striatum (mesolimbic), the mesocorticolimbic projection has a significant role in learning, motivation, reward, memory and movement.[13] Dopamine receptor subtypes, D1 and D2 have been shown to have complementary functions in the mesocorticolimbic projection, facilitating learning in response to both positive and negative feedback.This intricate neural circuit serves as a crucial communication route within the brain, facilitating the transmission of dopamine, a neurotransmitter associated with reward, motivation, and cognitive control.[19] The prefrontal cortex, being a central hub for executive functions, relies on the input from the mesocortical pathway to modulate and fine-tune cognitive processes essential for goal-directed behavior and decision-making.This neural circuit plays a pivotal role in the regulation of hormonal balance and, specifically, in modulating the secretion of prolactin from the pituitary gland, which is responsible for breast milk production in females.The decline in estrogen levels postpartum contributes to the restoration of dopaminergic inhibition, preventing sustained hyperprolactinemia in non-pregnant and non-nursing individuals.[35] Dopamine phasic activity also increases during cues that signal negative events, however dopaminergic neuron stimulation still induces place preference, indicating its main role in evaluating a positive stimulus.This model proposes that tonic dopaminergic firing increases the activity of the direct pathway, causing a bias towards executing actions faster.[36] These models of the basal ganglia are thought to be relevant to the study of OCD,[37][38] ADHD, Tourette syndrome, Parkinson's disease, schizophrenia, and addiction.
The main dopaminergic pathways of the human brain
The mesocorticolimbic pathway originates through the VTA and passes through the amygdala, nucleus accumbens, and hippocampus. These functions are relative to memory, emotional regulation, motivation, and reward.
The nigrostriatal pathway is involved in behaviors relating to movement and motivation.
The tuberoinfundibular pathway transmits dopamine the hypothalamus to the pituitary gland.
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