An Excitatory Adrenergic Synapse

An adrenergic synapse employs the neurotransmitter norepinephrine (NE), also called noradrenaline. NE, other monoamines, and neuropeptides act through second-messenger systems such as cyclic AMP (cAMP). The receptor is not an ion gate but an integral protein associated with a G protein. The binding of NE activates the G protein, which activates adenylate cyclase, which converts ATP to cAMP (fig. 12.20). The cAMP can have multiple effects such as stimulating the synthesis of new enzymes, activating preexisting enzymes, or opening ligand-regulated gates and producing a postsynaptic potential.

Figure 12.20 Transmission at an Adrenergic Synapse. The norepinephrine receptor is not an ion channel. It activates a second-messenger system with a variety of possible effects in the postsynaptic cell.

As complex as synaptic events may seem, they typically require only 0.5 msec or so—an interval called synaptic delay. This is the time from the arrival of a signal at the axon terminal of a presynaptic cell to the beginning of an action potential in the postsynaptic cell.

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Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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Responses

  • Martin
    What is the order of an excitatory adrenergic synapse?
    1 year ago
  • birgit
    What does g actin do in excitatory adrenergic synapse?
    9 months ago
  • jennifer
    Which neurotransmitter is found in an adrenergic synapse?
    7 months ago
  • jo
    What is the advantage of an adrenergic synapse?
    4 months ago

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