Homeostatic regulation of excitatory synapses on striatal medium spiny neurons expressing the D2 dopamine receptor
Abstract
Striatal medium spiny neurons (MSNs) are contacted by glutamatergic axon terminals originating from cortex, thalamus and other regions. The striatum is also innervated by dopaminergic (DAergic) terminals, some of which release glutamate as a co-transmitter. Despite evidence for functional DA release at birth in the striatum, the role of DA in the establishment of striatal circuitry is unclear. In light of recent work suggesting activity-dependent homeostatic regulation of glutamatergic terminals on MSNs expressing the D2 DA receptor (D2-MSNs), we used primary co-cultures to test the hypothesis that stimulation of DA and glutamate receptors regulates the homeostasis of glutamatergic synapses on MSNs. Co-culture of D2-MSNs with mesencephalic DA neurons or with cortical neurons produced an increase in spines and functional glutamate synapses expressing VGLUT2 or VGLUT1, respectively. The density of VGLUT2-positive terminals was reduced by the conditional knockout of this gene from DA neurons. In the presence of both mesencephalic and cortical neurons, the density of synapses reached the same total, compatible with the possibility of a homeostatic mechanism capping excitatory synaptic density. Blockade of D2 receptors increased the...Continue Reading
References
The dual dopamine-glutamate phenotype of growing mesencephalic neurons regresses in mature rat brain
Citations
Related Concepts
Related Feeds
Amygdala and Midbrain Dopamine
The midbrain dopamine system is widely studied for its involvement in emotional and motivational behavior. Some of these neurons receive information from the amygdala and project throughout the cortex. When the circuit and transmission of dopamine is disrupted symptoms may present. Here is the latest research on the amygdala and midbrain dopamine.
Basal Ganglia
Basal Ganglia are a group of subcortical nuclei in the brain associated with control of voluntary motor movements, procedural and habit learning, emotion, and cognition. Here is the latest research.