Final answer:
The deficiency found in narcolepsy is related to the neurotransmitter orexin, which ceases its discharge during sleep, leading to the disorder's symptoms. Treatment for narcolepsy has been evolving, with new medications targeting the orexin system.
Step-by-step explanation:
Deficiency Substance in Narcolepsy
The substance whose deficiency is found in narcolepsy is orexin (also known as hypocretin). Narcolepsy is characterized by reduced levels of this signaling molecule in certain areas of the brain. The specific neurons releasing orexin stop discharging during sleep, which affects the sleep-wake cycle and can lead to the symptoms of narcolepsy. It is important to note that traditional psychomotor stimulant drugs used to treat narcolepsy, such as amphetamines, do not have direct effects on the orexin system. There is ongoing research into new medications that target the hypocretin system directly to treat narcolepsy more effectively.
Other mentioned substances, such as GABA (gamma-aminobutyric acid), acetylcholine, and glutamate, are also neurotransmitters with their own functions and systems within the central nervous system. For instance, GABA is the main inhibitory neurotransmitter and plays a crucial role in regulating neuronal network activity and maintaining the excitatory-inhibitory balance.