Substance P: Difference between revisions

Line 1:

[[File:Substance_P.png|~~thumbnail~~|Substance P.]]

[[File:Substance_P.png|thumb|right|600px||The molecular structure of Substance P.]]

'''Substance P''' (SP) is a neuropeptide that functions as a neurotransmitter and neuromodulator affecting the neurokinin receptors. It has most closely been associated with nociception (pain perception),<ref name="pain">Substance P: Transmitter of nociception (minireview) | https://www.sav.sk/journals/endo/full/er0400e.pdf</ref> but seems to have a wide range of effects including an important role in nausea, emesis (vomiting), the rewarding effects of opiates, and likely in regulating stress responses and anxiety/depression-related behavior.<ref name="mood">The role of substance P in stress and anxiety responses | http://search.proquest.com/docview/68938022</ref> SP is found throughout the body, ~~both~~ in the brain, in peripheral nerve endings and in the spine. The full extent of its involvement in neurotransmission and its possible therapeutic or recreational implications is unclear.

'''Substance P''' (SP) is a neuropeptide that functions as a neurotransmitter and neuromodulator affecting the neurokinin receptors. It has most closely been associated with nociception (pain perception),<ref name="pain">Substance P: Transmitter of nociception (minireview) | https://www.sav.sk/journals/endo/full/er0400e.pdf</ref> but seems to have a wide range of effects including an important role in nausea, emesis (vomiting), the rewarding effects of opiates, and likely in regulating stress responses and anxiety/depression-related behavior.<ref name="mood">The role of substance P in stress and anxiety responses | http://search.proquest.com/docview/68938022</ref> SP is found throughout the body, in the brain, peripheral nerve endings and the spine. The full extent of its involvement in neurotransmission and its possible therapeutic or recreational implications is unclear.

==Chemical composition==

Line 12:

Line 13:

===Function as a neurotransmitter or neuromodulator===

Substance P does not function like a typical neurotransmitter. There exists no SP transporter to pump the peptide back into the axon terminal, unlike neurotransmitters like [[dopamine]] or [[serotonin]] which have protein pumps that function to recycle the neurotransmitter once it has left the receptor. Instead, SP must be ~~synthesized~~ from scratch again. However, SP is believed to be released beyond the synapse and may diffuse over larger distances than traditional neurotransmitters, which are limited to the [[synapse]], the tiny gap between one neuron on the sending end and one on the receiving one. Certain regions of the brain have many NK1 receptors but little Substance P or vice versa, which may have different explanations. One possible explanation is that SP may float over larger distances and subsist in the plasma surrounding cells for longer periods of time.

Substance P does not function like a typical neurotransmitter. There exists no SP transporter to pump the peptide back into the axon terminal, unlike neurotransmitters like [[dopamine]] or [[serotonin]] which have protein pumps that function to recycle the neurotransmitter once it has left the receptor. Instead, SP must be synthesised from scratch again. However, SP is believed to be released beyond the synapse and may diffuse over larger distances than traditional neurotransmitters, which are limited to the [[synapse]], the tiny gap between one neuron on the sending end and one on the receiving one. Certain regions of the brain have many NK1 receptors but little Substance P or vice versa, which may have different explanations. One possible explanation is that SP may float over larger distances and subsist in the plasma surrounding cells for longer periods of time.

==Role in pain perception and interaction with opioids==

@@ Line 1: / Line 1: @@
-[[File:Substance_P.png|thumbnail|Substance P.]]
+[[File:Substance_P.png|thumb|right|600px||The molecular structure of Substance P.]]
-'''Substance P''' (SP) is a neuropeptide that functions as a neurotransmitter and neuromodulator affecting the neurokinin receptors. It has most closely been associated with nociception (pain perception),<ref name="pain">Substance P: Transmitter of nociception (minireview) | https://www.sav.sk/journals/endo/full/er0400e.pdf</ref> but seems to have a wide range of effects including an important role in nausea, emesis (vomiting), the rewarding effects of opiates, and likely in regulating stress responses and anxiety/depression-related behavior.<ref name="mood">The role of substance P in stress and anxiety responses | http://search.proquest.com/docview/68938022</ref> SP is found throughout the body, both in the brain, in peripheral nerve endings and in the spine. The full extent of its involvement in neurotransmission and its possible therapeutic or recreational implications is unclear.
+'''Substance P''' (SP) is a neuropeptide that functions as a neurotransmitter and neuromodulator affecting the neurokinin receptors. It has most closely been associated with nociception (pain perception),<ref name="pain">Substance P: Transmitter of nociception (minireview) | https://www.sav.sk/journals/endo/full/er0400e.pdf</ref> but seems to have a wide range of effects including an important role in nausea, emesis (vomiting), the rewarding effects of opiates, and likely in regulating stress responses and anxiety/depression-related behavior.<ref name="mood">The role of substance P in stress and anxiety responses | http://search.proquest.com/docview/68938022</ref> SP is found throughout the body, in the brain, peripheral nerve endings and the spine. The full extent of its involvement in neurotransmission and its possible therapeutic or recreational implications is unclear.
 ==Chemical composition==
@@ Line 12: / Line 13: @@
 ===Function as a neurotransmitter or neuromodulator===
-Substance P does not function like a typical neurotransmitter. There exists no SP transporter to pump the peptide back into the axon terminal, unlike neurotransmitters like [[dopamine]] or [[serotonin]] which have protein pumps that function to recycle the neurotransmitter once it has left the receptor. Instead, SP must be synthesized from scratch again. However, SP is believed to be released beyond the synapse and may diffuse over larger distances than traditional neurotransmitters, which are limited to the [[synapse]], the tiny gap between one neuron on the sending end and one on the receiving one. Certain regions of the brain have many NK1 receptors but little Substance P or vice versa, which may have different explanations. One possible explanation is that SP may float over larger distances and subsist in the plasma surrounding cells for longer periods of time.
+Substance P does not function like a typical neurotransmitter. There exists no SP transporter to pump the peptide back into the axon terminal, unlike neurotransmitters like [[dopamine]] or [[serotonin]] which have protein pumps that function to recycle the neurotransmitter once it has left the receptor. Instead, SP must be synthesised from scratch again. However, SP is believed to be released beyond the synapse and may diffuse over larger distances than traditional neurotransmitters, which are limited to the [[synapse]], the tiny gap between one neuron on the sending end and one on the receiving one. Certain regions of the brain have many NK1 receptors but little Substance P or vice versa, which may have different explanations. One possible explanation is that SP may float over larger distances and subsist in the plasma surrounding cells for longer periods of time.
 ==Role in pain perception and interaction with opioids==