5-HT (5-hydroxytryptamine, serotonin) has a widespread occurrence in
numerous species of plants and animals. It is present for example in
several vegetables and edible fruits, in the urticant fluid of the
stinging nettle as well as in the intestine, blood platelets and nervous
system of all classes of vertebrates.
Its occurrence in the central nervous system (CNS) of both vertebrates
and invertebrates has attracted particular attention. In the CNS the
transmission of impulses from one nerve fibre to another is accomplished
by the action of chemical mediators, called neurotransmitters. The
junction between two nerve fibres is called synapse. At the arrival of
an action-potential the presynaptically stored transmitter is released
and subsequently causes the depolarization of the postsynaptic fibre as
consequence of the interaction with a specific receptor, which is a
molecular system incorporated in the post-synaptic membrane. 5-HT came
to be regarded as a possible neurotransmitter. However, direct evidence
for its neuronal localization was not presented until 1965 when Dahlstrom
and Fuxe actually demonstrated its presence within the perikarya of the
brain stem raphe nuclei and its projections in discrete regions of the
fore-brain.
Publication date
20/11/1974
Field of study
5-HT (5-hydroxytryptamine, serotonin) has a widespread occurrence in
numerous species of plants and animals. It is present for example in
several vegetables and edible fruits, in the urticant fluid of the
stinging nettle as well as in the intestine, blood platelets and nervous
system of all classes of vertebrates.
Its occurrence in the central nervous system (CNS) of both vertebrates
and invertebrates has attracted particular attention. In the CNS the
transmission of impulses from one nerve fibre to another is accomplished
by the action of chemical mediators, called neurotransmitters. The
junction between two nerve fibres is called synapse. At the arrival of
an action-potential the presynaptically stored transmitter is released
and subsequently causes the depolarization of the postsynaptic fibre as
consequence of the interaction with a specific receptor, which is a
molecular system incorporated in the post-synaptic membrane. 5-HT came
to be regarded as a possible neurotransmitter. However, direct evidence
for its neuronal localization was not presented until 1965 when Dahlstrom
and Fuxe actually demonstrated its presence within the perikarya of the
brain stem raphe nuclei and its projections in discrete regions of the
fore-brain
When employed correctly, local anaesthetics are very safe agents, though unwanted systemic reactions may still appear after administration of a local anaesthetic. Dentists should prevent these side effects as much as possible, recognize them at an early phase and treat them adequately