Medical pharmacology – Chapter 12 – pharmacological control in
the central nervous system
Acetylcholine
Serves as neurotransmitter at skeletal neuromuscular junctions and at
neuromuscular synapse. Involved in cholinergic neurotransmission
High concentration in corpus striatum and thalamus.
Low concentration in cerebellum
Neurotransmitter receptor
1. Nicotinic (AchM); substantia nigra, locus coeruleus, septum
2. Muscarinic (AchN); midbrain, pons and medulla
Defects in cholinergic neurotransmission lead to dementia (Alzheimer’s/ Huntington
disease)
Glutamate
Most important transmitter for normal brain function. It mediates excitatory input in
the brain
Neurotransmitter receptor:
1. AMPA, NMDA, kainite – ionotropic
2. Muscarinic glutamate receptor – metabotropic
GABA
GABA and glycine play a role in the brain as inhibitory transmitter.
Glucose --> glutamate --> GABA + pyridoxal phosphate by glutamic acid
decarboxylase (GAD)
GAT is responsible for re-uptake in neuron.
Neurotransmitter receptor
1. GABA-A; inotropic
Binding site for: GABA: increases Cl influx and cause hyperpolarization.
Binding site for: benzodiazepines (Valium, barbiturates); more
hyperpolarization, so more inhibiting cell. They suppress CNS so muscle
relaxant, induces sleep, fear inhibition, anti-spasm
2. GABA-B; metabotropic
Dopamine
inhibiotry and excitatory transmitter
3 systems:
1. Substantia nigra spread into neostriatum (caudate nucleus and putamen) =
Nigro-striatal system. Regulate motor skills. Hypofunction results in
Parkinson’s disease (motor disturbance)
2. Ventral tegmentum spread into limbic system or into neocortex = meso-limbic
and/or meso-cortical system. Regulate affection.
Libic – motiviation and rewards (belonging)
Cortical – attention and mental performance
the central nervous system
Acetylcholine
Serves as neurotransmitter at skeletal neuromuscular junctions and at
neuromuscular synapse. Involved in cholinergic neurotransmission
High concentration in corpus striatum and thalamus.
Low concentration in cerebellum
Neurotransmitter receptor
1. Nicotinic (AchM); substantia nigra, locus coeruleus, septum
2. Muscarinic (AchN); midbrain, pons and medulla
Defects in cholinergic neurotransmission lead to dementia (Alzheimer’s/ Huntington
disease)
Glutamate
Most important transmitter for normal brain function. It mediates excitatory input in
the brain
Neurotransmitter receptor:
1. AMPA, NMDA, kainite – ionotropic
2. Muscarinic glutamate receptor – metabotropic
GABA
GABA and glycine play a role in the brain as inhibitory transmitter.
Glucose --> glutamate --> GABA + pyridoxal phosphate by glutamic acid
decarboxylase (GAD)
GAT is responsible for re-uptake in neuron.
Neurotransmitter receptor
1. GABA-A; inotropic
Binding site for: GABA: increases Cl influx and cause hyperpolarization.
Binding site for: benzodiazepines (Valium, barbiturates); more
hyperpolarization, so more inhibiting cell. They suppress CNS so muscle
relaxant, induces sleep, fear inhibition, anti-spasm
2. GABA-B; metabotropic
Dopamine
inhibiotry and excitatory transmitter
3 systems:
1. Substantia nigra spread into neostriatum (caudate nucleus and putamen) =
Nigro-striatal system. Regulate motor skills. Hypofunction results in
Parkinson’s disease (motor disturbance)
2. Ventral tegmentum spread into limbic system or into neocortex = meso-limbic
and/or meso-cortical system. Regulate affection.
Libic – motiviation and rewards (belonging)
Cortical – attention and mental performance
