Basket cells
**Core Concept**
Basket cells are a type of inhibitory interneuron found in the cerebral cortex, playing a crucial role in regulating neuronal excitability and synaptic plasticity. They are characterized by their distinctive basket-like arrangement of axonal terminals that form synaptic contacts with the soma of pyramidal neurons.
**Why the Correct Answer is Right**
Basket cells primarily use GABA (gamma-aminobutyric acid) as their neurotransmitter, which acts on GABA_A receptors to produce an inhibitory effect on the target neuron. This inhibitory action helps to regulate the firing of pyramidal neurons and maintain the balance of neural activity in the cortex. The basket-like arrangement of their axonal terminals allows them to effectively modulate the excitability of pyramidal neurons.
**Why Each Wrong Option is Incorrect**
**Option A:** Basket cells are not primarily involved in the regulation of the blood-brain barrier.
**Option B:** Basket cells do not primarily use glutamate as their neurotransmitter; they use GABA instead.
**Option C:** Basket cells are not a type of glial cell, but rather a type of neuron that plays a key role in regulating neural activity.
**Clinical Pearl / High-Yield Fact**
Basket cells are an important example of how inhibitory interneurons can regulate neural activity and maintain the balance of excitatory and inhibitory inputs in the cortex. Dysfunction of basket cells has been implicated in various neurological and psychiatric disorders, including epilepsy and schizophrenia.
**Correct Answer: D**