Which of the following basal ganglia nucleus is primarily glutaminergic
**Core Concept**
The basal ganglia are a group of subcortical structures that play a crucial role in movement control and cognition. They are characterized by their distinct neurotransmitter profiles, with different nuclei exhibiting excitatory or inhibitory functions. The glutaminergic system is involved in the excitatory transmission within the basal ganglia.
**Why the Correct Answer is Right**
The subthalamic nucleus (STN) is primarily glutaminergic, releasing glutamate as its neurotransmitter. This excitatory input from the STN to the globus pallidus interna (GPi) and substantia nigra pars reticulata (SNr) is crucial for the regulation of motor function. The glutaminergic transmission in the STN is mediated by NMDA and AMPA receptors, which are involved in the excitatory synaptic transmission.
**Why Each Wrong Option is Incorrect**
* **Option A:** The globus pallidus externa (GPe) is primarily GABAergic, releasing GABA as its neurotransmitter. The GPe receives input from the striatum and projects to the subthalamic nucleus and globus pallidus interna.
* **Option B:** The substantia nigra pars compacta (SNc) is primarily dopaminergic, releasing dopamine as its neurotransmitter. The SNc projects to the striatum and is involved in the regulation of motor function.
* **Option D:** The entopeduncular nucleus (EPN) is also known as the ventral pallidum and is primarily GABAergic, releasing GABA as its neurotransmitter. The EPN receives input from the globus pallidus interna and projects to the thalamus.
**Clinical Pearl / High-Yield Fact**
The subthalamic nucleus is a key target for deep brain stimulation in the treatment of Parkinson's disease, as it helps to regulate motor function and alleviate symptoms such as tremors and rigidity.
**Correct Answer: C. Subthalamic nucleus**