answers: reward and movement
context: Luigi Rolando. It corresponds to Rexed lamina II. The substantia gelatinosa is one point (the nucleus proprius being the other) where first order neurons of the spinothalamic tract synapse. Many μ and κ-opioid receptors, presynaptic and postsynaptic, are found on these nerve cells; they can be targeted to manage pain of distal origin. For instance, neuraxial administration of opioids results in analgesia primarily by action in the dorsal horn of the spinal cord in the substantia gelatinosa where they inhibit release of excitatory neurotransmitters such as substance P and glutamate and inhibit afferent neural transmission to the brain from incoming </s> Unlike the midbrain tectum (which is a sensory structure located posteriorly), the midbrain tegmentum, which locates anteriorly, is related to a number of motor functions. Within the tegmentum, the red nucleus is in charge of motor coordination (specifically for limb movements) and the periaqueductal gray matter (PAG) contains critical circuits for modulating behavioral responses to pains. The substantia nigra (black substance) serves an important role in rewarding behaviors such as approaching desired objects. In addition, the substantia nigra forms reciprocal connections with the basal ganglia which are highly correlated with motor functions and learning. The midbrain tegmentum is also an </s> Substantia nigra The substantia nigra (SN) is a basal ganglia structure located in the midbrain that plays an important role in reward and movement. "Substantia nigra" is Latin for "black substance", reflecting the fact that parts of the substantia nigra appear darker than neighboring areas due to high levels of neuromelanin in dopaminergic neurons. It was discovered in 1784 by Félix Vicq-d'Azyr, and Samuel Thomas von Sömmerring alluded to this structure in 1791. Parkinson's disease is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta. Although the substantia nigra appears as a continuous band in brain
question: the midbrain includes the substantia nigra which is responsible for what