Activation of which of the following receptors would be expected to decrease anxiety
**Core Concept**
Activation of GABA_A receptors is a therapeutic target for anxiolytic medications, as it enhances inhibitory neurotransmission in the brain. GABA_A receptors are chloride channels that, when activated, promote hyperpolarization of neurons, reducing excitability and anxiety.
**Why the Correct Answer is Right**
The correct answer is associated with the activation of GABA_A receptors, which increases the inhibitory neurotransmission in the brain. This is achieved through the binding of agonists to the receptor, such as benzodiazepines (e.g., diazepam), which enhance the receptor's activity. The activation of GABA_A receptors leads to the opening of chloride channels, resulting in an influx of chloride ions and a hyperpolarization of the neurons, which in turn reduces neuronal excitability and anxiety.
**Why Each Wrong Option is Incorrect**
* **Option A:** This receptor is associated with the activation of the sympathetic nervous system, leading to increased anxiety and stress. Activation of this receptor would not decrease anxiety.
* **Option B:** This receptor is involved in the regulation of pain and inflammation, and its activation would not directly affect anxiety.
* **Option C:** This receptor is associated with the regulation of blood pressure and cardiovascular function, and its activation would not directly decrease anxiety.
**Clinical Pearl / High-Yield Fact**
Benzodiazepines, which activate GABA_A receptors, are commonly used as anxiolytics, but they can be habit-forming and should be used with caution.
**Correct Answer: D. GABA_A receptors**