Basic Neurophysiology - Revision history

Wdoyon: /* Signal to Noise Ratio */

2021-08-19T00:59:46Z

Signal to Noise Ratio

← Older revision		Revision as of 19:59, 18 August 2021
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	=== Signal to Noise Ratio ===		=== Signal to Noise Ratio ===

	Signal to noise ratio refers to the electrical or ~~neuruphysiological~~ signal and the concurrent interference (noise). Interference occurs both naturally and artificially. For example, “noise” from the body (extraneous biological activity) or perisurgical such as the use of instrumentation or electrical interference. The amplitude of the signal and the amplitude of the noise overlap given that the frequency content of noise contains a myriad of all frequencies and the specific frequency content of the signal would be within that range of all frequencies (Zouridakis and Papanicoloau, 2000). Therefore, to increase specificity and detection of the electrical signal, the signal to noise ratio, the interference must be dampened which can be accomplished using filters as described above and the signal may be increased using averaging.		Signal to noise ratio refers to the electrical or neurophysiological signal and the concurrent interference (noise). Interference occurs both naturally and artificially. For example, “noise” from the body (extraneous biological activity) or perisurgical such as the use of instrumentation or electrical interference. The amplitude of the signal and the amplitude of the noise overlap given that the frequency content of noise contains a myriad of all frequencies and the specific frequency content of the signal would be within that range of all frequencies (Zouridakis and Papanicoloau, 2000). Therefore, to increase specificity and detection of the electrical signal, the signal to noise ratio, the interference must be dampened which can be accomplished using filters as described above and the signal may be increased using averaging.

	=== Signal Averaging ===		=== Signal Averaging ===

Bpw: /* References */

2018-04-12T11:57:07Z

References

← Older revision		Revision as of 06:57, 12 April 2018
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	# Hodgkin AL and Huxley AF. "A quantitative description of membrane current and its application to conduction and excitation in nerve". The Journal of Physiology 117.4 (1952): 500–544.		# Hodgkin AL and Huxley AF. "A quantitative description of membrane current and its application to conduction and excitation in nerve". The Journal of Physiology 117.4 (1952): 500–544.

	# Moller, A. (1995). Intraoperative Neurophysiologic Monitoring. Informa Healthcare.		# Moller, A. (1995). Intraoperative Neurophysiologic Monitoring. Informa Healthcare.

	# Pinel, J. P. J. (2014). Biopsychology. Harlow, Essex: Pearson Education Limited.		# Pinel, J. P. J. (2014). Biopsychology. Harlow, Essex: Pearson Education Limited.

	# Zouridakis, G. and Papanicoloau, A.C. (2000). A Concise Guide to Intraoperative Monitoring. CRC Press: Taylor and Francis Group.		# Zouridakis, G. and Papanicoloau, A.C. (2000). A Concise Guide to Intraoperative Monitoring. CRC Press: Taylor and Francis Group.

Bpw: /* References */

2018-04-12T11:56:51Z

References

← Older revision		Revision as of 06:56, 12 April 2018
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	==References==		==References==

	Hodgkin AL and Huxley AF. "A quantitative description of membrane current and its application to conduction and excitation in nerve". The Journal of Physiology 117.4 (1952): 500–544.		# Hodgkin AL and Huxley AF. "A quantitative description of membrane current and its application to conduction and excitation in nerve". The Journal of Physiology 117.4 (1952): 500–544.

	Moller, A. (1995). Intraoperative Neurophysiologic Monitoring. Informa Healthcare.		# Moller, A. (1995). Intraoperative Neurophysiologic Monitoring. Informa Healthcare.

	Pinel, J. P. J. (2014). Biopsychology. Harlow, Essex: Pearson Education Limited.		# Pinel, J. P. J. (2014). Biopsychology. Harlow, Essex: Pearson Education Limited.

	Zouridakis, G. and Papanicoloau, A.C. (2000). A Concise Guide to Intraoperative Monitoring. CRC Press: Taylor and Francis Group.		# Zouridakis, G. and Papanicoloau, A.C. (2000). A Concise Guide to Intraoperative Monitoring. CRC Press: Taylor and Francis Group.

Bpw: /* Propagated Neural Activity */

2018-04-11T23:35:10Z

Propagated Neural Activity

← Older revision		Revision as of 18:35, 11 April 2018
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	An action potential is generated near the axon hillock when the threshold is reached (-65 mV), the signal is then propagated down (travels) the axon. Active axonal conduction is due to the diffusion of Na+ into the cell which creates waves of depolarization whereas passive axonal conduction occurs as the signal travels down a myelinated axon along each segment, an action potential is generated at each node of Ranvier between the segments (Pinel, 2017) propagated from one node to the next (saltatory conduction).		An action potential is generated near the axon hillock when the threshold is reached (-65 mV), the signal is then propagated down (travels) the axon. Active axonal conduction is due to the diffusion of Na+ into the cell which creates waves of depolarization whereas passive axonal conduction occurs as the signal travels down a myelinated axon along each segment, an action potential is generated at each node of Ranvier between the segments (Pinel, 2017) propagated from one node to the next (saltatory conduction).

	[[File:ion-~~channels~~.png\|center\|974px\|560px]]		[[File:ion-channels2.png\|center\|974px\|560px]]

	(Source: Wikipedia, https://en.wikipedia.org/wiki/Saltatory_conduction)		(Source: Wikipedia, https://en.wikipedia.org/wiki/Saltatory_conduction)

Bpw: /* Synaptic Transmission */

2018-04-11T23:28:28Z

Synaptic Transmission

← Older revision		Revision as of 18:28, 11 April 2018
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	The process by which neurons communicate with each other is synaptic transmission which occurs across synapses using either electrical or chemical signals. Electrical signaling occurs as an action potential travels from the pre- to the postsynaptic neuron via gap junctions. However, most synaptic transmission involves chemical signals. These chemicals are neurotransmitters, molecules which can function either directly (ionotropic) or indirectly via second messengers (metabotropic). The steps in chemical neurotransmission are: synthesis of the neurotransmitter (in the soma), storage of the neurotransmitter in the vesicles, release into the synapse, binding to the receptor on the postsynaptic neuron, and inactivation of the neurotransmitter via reuptake or enzymatic degradation which terminates the action of the neurotransmitter in the synapse.		The process by which neurons communicate with each other is synaptic transmission which occurs across synapses using either electrical or chemical signals. Electrical signaling occurs as an action potential travels from the pre- to the postsynaptic neuron via gap junctions. However, most synaptic transmission involves chemical signals. These chemicals are neurotransmitters, molecules which can function either directly (ionotropic) or indirectly via second messengers (metabotropic). The steps in chemical neurotransmission are: synthesis of the neurotransmitter (in the soma), storage of the neurotransmitter in the vesicles, release into the synapse, binding to the receptor on the postsynaptic neuron, and inactivation of the neurotransmitter via reuptake or enzymatic degradation which terminates the action of the neurotransmitter in the synapse.

	synapses.png		[[File:synapses.png\|center\|600px\|387px]]

			(Source: http://biology4alevel.blogspot.com/2016/06/122-synapses.html)

	== Recording Techniques ==		== Recording Techniques ==

Bpw: /* Synaptic Transmission */

2018-04-11T23:25:26Z

Synaptic Transmission

← Older revision		Revision as of 18:25, 11 April 2018
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	The process by which neurons communicate with each other is synaptic transmission which occurs across synapses using either electrical or chemical signals. Electrical signaling occurs as an action potential travels from the pre- to the postsynaptic neuron via gap junctions. However, most synaptic transmission involves chemical signals. These chemicals are neurotransmitters, molecules which can function either directly (ionotropic) or indirectly via second messengers (metabotropic). The steps in chemical neurotransmission are: synthesis of the neurotransmitter (in the soma), storage of the neurotransmitter in the vesicles, release into the synapse, binding to the receptor on the postsynaptic neuron, and inactivation of the neurotransmitter via reuptake or enzymatic degradation which terminates the action of the neurotransmitter in the synapse.		The process by which neurons communicate with each other is synaptic transmission which occurs across synapses using either electrical or chemical signals. Electrical signaling occurs as an action potential travels from the pre- to the postsynaptic neuron via gap junctions. However, most synaptic transmission involves chemical signals. These chemicals are neurotransmitters, molecules which can function either directly (ionotropic) or indirectly via second messengers (metabotropic). The steps in chemical neurotransmission are: synthesis of the neurotransmitter (in the soma), storage of the neurotransmitter in the vesicles, release into the synapse, binding to the receptor on the postsynaptic neuron, and inactivation of the neurotransmitter via reuptake or enzymatic degradation which terminates the action of the neurotransmitter in the synapse.

			synapses.png

	== Recording Techniques ==		== Recording Techniques ==

Bpw: /* Propagated Neural Activity */

2018-04-11T23:24:14Z

Propagated Neural Activity

← Older revision		Revision as of 18:24, 11 April 2018
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	[[File:ion-channels.png\|center\|974px\|560px]]		[[File:ion-channels.png\|center\|974px\|560px]]

			(Source: Wikipedia, https://en.wikipedia.org/wiki/Saltatory_conduction)

	Axons that are wrapped in myelin (fatty substance), which serves as insulation of the signal, have faster communication than unmyelinated axons. The nodes of Ranvier are unmyelinated areas on the axon where the ions flow (e.g., Na+, K+).		Axons that are wrapped in myelin (fatty substance), which serves as insulation of the signal, have faster communication than unmyelinated axons. The nodes of Ranvier are unmyelinated areas on the axon where the ions flow (e.g., Na+, K+).

Bpw: /* Propagated Neural Activity */

2018-04-11T23:23:16Z

Propagated Neural Activity

← Older revision		Revision as of 18:23, 11 April 2018
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	An action potential is generated near the axon hillock when the threshold is reached (-65 mV), the signal is then propagated down (travels) the axon. Active axonal conduction is due to the diffusion of Na+ into the cell which creates waves of depolarization whereas passive axonal conduction occurs as the signal travels down a myelinated axon along each segment, an action potential is generated at each node of Ranvier between the segments (Pinel, 2017) propagated from one node to the next (saltatory conduction).		An action potential is generated near the axon hillock when the threshold is reached (-65 mV), the signal is then propagated down (travels) the axon. Active axonal conduction is due to the diffusion of Na+ into the cell which creates waves of depolarization whereas passive axonal conduction occurs as the signal travels down a myelinated axon along each segment, an action potential is generated at each node of Ranvier between the segments (Pinel, 2017) propagated from one node to the next (saltatory conduction).

	[[File:ion-channels.png\|center\|~~730px~~\|~~420px~~]]		[[File:ion-channels.png\|center\|974px\|560px]]

	Axons that are wrapped in myelin (fatty substance), which serves as insulation of the signal, have faster communication than unmyelinated axons. The nodes of Ranvier are unmyelinated areas on the axon where the ions flow (e.g., Na+, K+).		Axons that are wrapped in myelin (fatty substance), which serves as insulation of the signal, have faster communication than unmyelinated axons. The nodes of Ranvier are unmyelinated areas on the axon where the ions flow (e.g., Na+, K+).

Bpw: /* Propagated Neural Activity */

2018-04-11T23:22:48Z

Propagated Neural Activity

← Older revision		Revision as of 18:22, 11 April 2018
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	An action potential is generated near the axon hillock when the threshold is reached (-65 mV), the signal is then propagated down (travels) the axon. Active axonal conduction is due to the diffusion of Na+ into the cell which creates waves of depolarization whereas passive axonal conduction occurs as the signal travels down a myelinated axon along each segment, an action potential is generated at each node of Ranvier between the segments (Pinel, 2017) propagated from one node to the next (saltatory conduction).		An action potential is generated near the axon hillock when the threshold is reached (-65 mV), the signal is then propagated down (travels) the axon. Active axonal conduction is due to the diffusion of Na+ into the cell which creates waves of depolarization whereas passive axonal conduction occurs as the signal travels down a myelinated axon along each segment, an action potential is generated at each node of Ranvier between the segments (Pinel, 2017) propagated from one node to the next (saltatory conduction).

	[[File:ion-channels.png]]		[[File:ion-channels.png\|center\|730px\|420px]]

	Axons that are wrapped in myelin (fatty substance), which serves as insulation of the signal, have faster communication than unmyelinated axons. The nodes of Ranvier are unmyelinated areas on the axon where the ions flow (e.g., Na+, K+).		Axons that are wrapped in myelin (fatty substance), which serves as insulation of the signal, have faster communication than unmyelinated axons. The nodes of Ranvier are unmyelinated areas on the axon where the ions flow (e.g., Na+, K+).

Bpw: /* Propagated Neural Activity */

2018-04-11T23:16:54Z

Propagated Neural Activity

← Older revision		Revision as of 18:16, 11 April 2018
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	An action potential is generated near the axon hillock when the threshold is reached (-65 mV), the signal is then propagated down (travels) the axon. Active axonal conduction is due to the diffusion of Na+ into the cell which creates waves of depolarization whereas passive axonal conduction occurs as the signal travels down a myelinated axon along each segment, an action potential is generated at each node of Ranvier between the segments (Pinel, 2017) propagated from one node to the next (saltatory conduction).		An action potential is generated near the axon hillock when the threshold is reached (-65 mV), the signal is then propagated down (travels) the axon. Active axonal conduction is due to the diffusion of Na+ into the cell which creates waves of depolarization whereas passive axonal conduction occurs as the signal travels down a myelinated axon along each segment, an action potential is generated at each node of Ranvier between the segments (Pinel, 2017) propagated from one node to the next (saltatory conduction).

			[[File:ion-channels.png]]

	Axons that are wrapped in myelin (fatty substance), which serves as insulation of the signal, have faster communication than unmyelinated axons. The nodes of Ranvier are unmyelinated areas on the axon where the ions flow (e.g., Na+, K+).		Axons that are wrapped in myelin (fatty substance), which serves as insulation of the signal, have faster communication than unmyelinated axons. The nodes of Ranvier are unmyelinated areas on the axon where the ions flow (e.g., Na+, K+).