Nociception sleep

The plant alkaloids mimic the endogenous peptides enkephalins and endorphins (Chapter 12), which meditate nociception and sleep. There are three types of widely distributed opiate receptors. Mu receptors are concentrated in neocortex, striatum, thalamus, hippocampus, amygdala and spinal cord, delta receptors in neocortex and amydala, and kappa receptors in striatum, amygdala and hypothalamus (Mansour et al., 1988). 

For almost one century, acetylcholine has been recognized as a neurotransmitter both in the central nervous system and the peripheral nervous system. In the peripheral nervous system, acetylcholine has been identified as the neurotransmitter of autonomic ganglia and the neuromuscular junction. Acetylcholine is involved in different peripheral functions such as heart rate, blood flow, gastrointestinal tract motility, and sweat production and smooth muscle activity. In the CNS, cholinergic neurotransmission plays a crucial role in a variety of CNS functions including sensory perception, motor function, cognitive processing, memory, arousal, attention, sleep, nociception, motivation, reward, mood, and psychosis. 

Serotonin (5-hydroxytryptamine 5-HT) is involved in the regulation of the cardiovascular and respiratory systems, sleep, aggression, sexual behavior, food intake, anxiety, mood, motor output, neuroendocrine secretion, nociception, and analgesia. 

---