1-Introduction to Pharmacology of CNS
Drugs
A- Intro
1- Brain neurons communicate by releasing neurotransmitters that evoke postsynaptic
electrical response through binding to receptors
2- Two major classes of receptors:
‣ Receptors that are also ion channels ( ionotropic ): fast but
short response
‣ Receptors are separate than ion channels ( metabolic receptors ): Slow but longer response
B- Central Neurotransmitters:
1- Neuropeptides: relatively large transmitter molecules composed of 3 to
36 amino acids
, 2- Monoamines ( Biogenic amines )
‣ They are active in both peripheral and central nervous system and have many functions
like regulating homeostasis and cognition therefore they are implicated in most
psychiatric disorders and many drugs of abuse act through them.
• Dopamine: Major dopamine containing area in the brain is corpus striatum, which receives
input from substantia nigra ( Nigrostriatal pathway ) and play an essential role in
coordination of body movement.
◦Parkinson’s disease : the dopaminergic neurons of the substantia nigra degenerate
◦Basal ganglia: also known as the extrapyramidal system (EPS), play a crucial role in
coordinating and regulating muscular activity. They receive input from various brain
areas involved in movement, such as the cerebral cortex and
cerebellum. Unlike the pyramidal system, which directly controls
skeletal muscle activity, the extrapyramidal system helps to
modulate and ne-tune this activity. Degeneration of dopamine-
producing neurons within the basal ganglia is responsible for
Parkinson’s disease, leading to symptoms like tremors, muscular rigidity, and movement
dif culties.
◦Da control many physiological processes in the brain including reward, cognition,
memory and motor activity through 4 pathways:
‣ Mesolimbic: is associated with the reward system and to a
lesser degree the learning. Dysfunction -> addiction,
schizophrenia and psychosis ( including bipolar and
Drugs
A- Intro
1- Brain neurons communicate by releasing neurotransmitters that evoke postsynaptic
electrical response through binding to receptors
2- Two major classes of receptors:
‣ Receptors that are also ion channels ( ionotropic ): fast but
short response
‣ Receptors are separate than ion channels ( metabolic receptors ): Slow but longer response
B- Central Neurotransmitters:
1- Neuropeptides: relatively large transmitter molecules composed of 3 to
36 amino acids
, 2- Monoamines ( Biogenic amines )
‣ They are active in both peripheral and central nervous system and have many functions
like regulating homeostasis and cognition therefore they are implicated in most
psychiatric disorders and many drugs of abuse act through them.
• Dopamine: Major dopamine containing area in the brain is corpus striatum, which receives
input from substantia nigra ( Nigrostriatal pathway ) and play an essential role in
coordination of body movement.
◦Parkinson’s disease : the dopaminergic neurons of the substantia nigra degenerate
◦Basal ganglia: also known as the extrapyramidal system (EPS), play a crucial role in
coordinating and regulating muscular activity. They receive input from various brain
areas involved in movement, such as the cerebral cortex and
cerebellum. Unlike the pyramidal system, which directly controls
skeletal muscle activity, the extrapyramidal system helps to
modulate and ne-tune this activity. Degeneration of dopamine-
producing neurons within the basal ganglia is responsible for
Parkinson’s disease, leading to symptoms like tremors, muscular rigidity, and movement
dif culties.
◦Da control many physiological processes in the brain including reward, cognition,
memory and motor activity through 4 pathways:
‣ Mesolimbic: is associated with the reward system and to a
lesser degree the learning. Dysfunction -> addiction,
schizophrenia and psychosis ( including bipolar and
