postsynaptic neuron

(noun)

The nerve cell that bears receptors for neurotransmitters released into the synaptic cleft by the presynaptic neuron.

Related Terms

Examples of postsynaptic neuron in the following topics:

  • Postsynaptic Potentials and Their Integration at the Synapse

    • Postsynaptic potentials are changes in the membrane potential of the postsynaptic terminal of a chemical synapse.
    • Chemical synapses are either excitatory or inhibitory depending on how they affect the membrane potential of the postsynaptic neuron.
    • This is an excitatory postsynaptic potential (EPSP) as it brings the neuron's potential closer to its firing threshold (about -50mV).
    • Neurotransmitter binding at inhibitory synapses reduces a postsynaptic neuron's ability to generate an action potential.
    • A single EPSP at one synapse is generally far too small to trigger an action potential in the postsynaptic neuron.

  • The Synapse

    • The neuron transmitting the electrical impulse away from the synapse is called postsynaptic neuron.
    • At a synapse , the presynaptic neuron sends information and postsynaptic neuron receives the information.
    • Most neurons, function as both as presynaptic and postsynaptic neurons.
    • In a chemical synapse, the plasma membrane of the signal-passing neuron (the presynaptic neuron) comes into close apposition with the membrane of the target (postsynaptic) cell.
    • A: Neuron (Presynaptic) B: Neuron (Postsynaptic)MitochondriaSynaptic vesicle full of neurotransmitterAutoreceptorSynaptic cleftNeurotransmitter receptorCalcium ChannelFused vesicle releasing neurotransmitterNeurotransmitter re-uptake pump

  • Autonomic Ganglia

    • The axons of dorsal root ganglion neurons are known as afferents.
    • The first neuron in this pathway is referred to as the preganglionic or presynaptic neuron.
    • This second neuron is referred to as the postganglionic or postsynaptic neuron.
    • As a result, the postsynaptic parasympathetic nerve fibers are very short.
    • The pathways of the ciliary ganglion include sympathetic neurons (red), parasympathetic neurons (green), and sensory neurons (blue).

  • Function and Physiology of the Spinal Nerves

    • In the parasympathetic system, ganglionic neurons use acetylcholine as a neurotransmitter to stimulate muscarinic receptors.
    • At the adrenal medulla, there is no postsynaptic neuron.
    • Instead the presynaptic neuron releases acetylcholine to act on nicotinic receptors.
    • Upper motor neurons release acetylcholine.
    • Acetylcholine is released from the axon terminal knobs of alpha motor neurons and received by postsynaptic receptors (nicotinic acetylcholine receptors) of muscles, thereby relaying the stimulus to contract muscle fibers.

  • Postganglionic Neurons

    • At the synapses within the ganglia, the preganglionic neurons release acetylcholine, a neurotransmitter that activates nicotinic acetylcholine receptors on postganglionic neurons.
    • The postsynaptic cell then goes on to innervate the targeted end effector (i.e., gland, smooth muscle, etc.).
    • Because paravertebral and prevertebral ganglia are relatively close to the spinal cord, presynaptic neurons are generally much shorter than their postsynaptic counterparts, which must extend throughout the body to reach their destinations.
    • The axons of presynaptic parasympathetic neurons are usually long.
    • As a result, the postsynaptic parasympathetic nerve fibers are very short.

  • Development of Nervous Tissue

    • Embryonic neural development includes the birth and differentiation of neurons from stem cell precursors.
    • In vertebrates, landmarks of embryonic neural development include the birth and differentiation of neurons from stem cell precursors, the migration of immature neurons from their birthplaces in the embryo to their final positions, outgrowth of axons from neurons and guidance of the motile growth cone through the embryo towards postsynaptic partners, the generation of synapses between these axons and their postsynaptic partners, and finally the lifelong changes in synapses which are thought to underlie learning and memory.
    • A GMC divides once, to give rise to either a pair of neurons or a pair of glial cells.
    • In all, a neuroblast is capable of generating an indefinite number of neurons or glia.
    • DNT1 shares structural similarity with all known neurotrophins and is a key factor in the fate of neurons in Drosophila.

  • Preganglionic Neurons

    • The ANS is unique in that it requires a sequential two-neuron efferent pathway; the preganglionic neuron must first cross a synapse onto a postganglionic neuron before innervating the target organ.
    • These cell bodies are GVE (general visceral efferent) neurons and are the preganglionic neurons.
    • There are several locations where preganglionic neurons create synapses with their postganglionic neurons:
    • These are the preganglionic neurons that synapse with the postganglionic neurons in these locations :
    • Another major difference between the two ANS systems is divergence, or the number of postsynaptic fibers a single preganglionic fiber creates a synapse with.

  • Types of Neurotransmitters by Function

    • Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse.
    • They are released into and diffuse across the synaptic cleft, where they bind to specific receptors in the membrane on the postsynaptic side of the synapse.
    • Acetylcholine-releasing neurons are also found in the central nervous system (CNS).
    • Additionally, some motor neurons of the ANS release catecholamines like NE.
    • Chemical synapses are specialized junctions through which neurons signal to each other and to non-neuronal cells such as those in muscles or glands.

  • Parasympathetic (Craniosacral) Division

    • The motor root carries presynaptic parasympathetic nerve fibers (general visceral efferent fibers) that terminate in the ganglion by creating a synapse for the postsynaptic fibers traveling to target organs.
    • The sympathetic root carries postsynaptic sympathetic fibers (general visceral efferent fibers) that traverse the ganglion without creating a synapse.
    • The parasympathetic division has craniosacral outflow, meaning that the neurons begin at the cranial nerves (CN3, CN7, CN9, CN10) and the sacral spinal cord (S2–S4).

  • Peripheral Motor Endings

    • A neuromuscular junction is the synapse or junction of the axon terminal of a motor neuron with the motor end plate, as shown in Figures 1 and 2.
    • Upon the arrival of an action potential at the presynaptic neuron terminal, voltage-dependent calcium channels open and Ca2+ ions flow from the extracellular fluid into the presynaptic neuron's cytosol.
    • This influx of Ca2+ causes neurotransmitter-containing vesicles to dock and fuse to the presynaptic neuron's cell membrane, which results in the emptying of the vesicle's contents (acetylcholine) into the synaptic cleft; this process is known as exocytosis.
    • The affects of myasthenia gravis illustrate the importance of effective and functioning neuromuscular junctions for communication between neurons and muscles to allow contraction and relaxation of muscle fibers.
    • Postsynaptic densities are visible on the tips between the folds.