Increased tendency to fall asleep at night without causing central nervous system depression is a property exhibited by :
**Core Concept**
The question is testing the pharmacological properties of certain medications, specifically their ability to induce drowsiness without causing central nervous system (CNS) depression. This property is often referred to as sedation without significant impairment of cognitive function.
**Why the Correct Answer is Right**
The correct answer is a medication that acts on the GABA receptors in the brain. GABA (Gamma-Aminobutyric Acid) is an inhibitory neurotransmitter that helps to regulate the activity of neurons. By enhancing GABA's activity, the medication increases the activity of GABA receptors, leading to sedation without significant impairment of cognitive function. This is because the GABA receptors are located in the limbic system, which is responsible for regulating emotions and arousal, rather than the cortex, which is responsible for cognitive function.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is a medication that acts on the histamine receptors in the brain, which is responsible for regulating arousal and alertness. Medications that act on histamine receptors are more likely to cause CNS depression and impair cognitive function.
**Option B:** This option is incorrect because it is a medication that acts on the dopamine receptors in the brain, which is responsible for regulating movement and motivation. Medications that act on dopamine receptors are more likely to cause CNS stimulation and impair motor function.
**Option C:** This option is incorrect because it is a medication that acts on the norepinephrine receptors in the brain, which is responsible for regulating attention and arousal. Medications that act on norepinephrine receptors are more likely to cause CNS stimulation and impair cognitive function.
**Clinical Pearl / High-Yield Fact**
Medications that act on GABA receptors, such as benzodiazepines, can cause sedation without significant impairment of cognitive function, making them useful for treating insomnia and anxiety disorders. However, they can also cause dependence and withdrawal symptoms, so they should be used with caution.
**Correct Answer:** C.