Mesial temporal dopamine: From biology to behaviour

While colloquially recognized for its role in pleasure, reward, and affect, dopamine is also necessary for proficient action control. Many motor studies focus on dopaminergic transmission along the nigrostriatal pathway, using Parkinson's disease as a model of a dorsal striatal lesion. Less attention to the mesolimbic pathway and its role in motor control has led to an important question related to the limbic-motor network. Indeed, secondary targets of the mesolimbic pathway include the hippocampus and amygdala, and these are linked to the motor cortex through the substantia nigra and thalamus. The modulatory impact of dopamine in the hippocampus and amygdala in humans is a focus of current investigations. This review explores dopaminergic activity in the mesial temporal lobe by summarizing dopaminergic networks and transmission in these regions and examining their role in behaviour and disease. Dopaminergic activity in the mesial temporal lobe (MTL) plays a role in both behaviour and cognition in healthy humans and symptoms in neurological disorders. Dopamine (DA) projections to the MTL can arise from the midbrain and locus coeruleus and subsequently interact with D1-like and D2-like receptors. MTL dopamine activity is instrumental in memory and impulsivity, with changes to the MTL dopaminergic system contributing to emotional dysregulation, memory loss, and psychotic symptoms in disease states.image

Automated summary

Dopamine plays a crucial role not only in pleasure, reward, and affect, but also in proficient action control. The mesolimbic pathway, connecting regions such as the hippocampus and amygdala to the motor cortex via the substantia nigra and thalamus, has been less studied compared to the nigrostriatal pathway. Dopaminergic activity in the mesial temporal lobe is involved in memory, impulsivity, and emotional regulation, and alterations in this system can contribute to neurological disorders.