Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology of Neuroscience 1 > Sensory 2 > Flashcards

Sensory 2 Flashcards

1
Q

Types of synaptic potentials

A

1) Postsynaptic potentials
2) Presynaptic potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Types of postsynaptic potentials

A

1) EPSP
2) IPSP
3) GPSP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Types of presynaptic potentials

A

1) Presynaptic Inhibition
2) Presynaptic facilitation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is EPSP?

A
  • A local state of partial depolarization of the postsynaptic membrane.
  • Produced as a result of binding of an exitatory neurotransmittrer with its receptors.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Ionic basis of EPSP

A
  • Opening of ligand-gated Na+ (or Ca++) channels.
  • Closure of Cl- channels.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

EPSP on neuron potential

A

It makes the inside of the cell membrane less negative, thereby more excitable as it is now nearer to the firing level.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Maximum of EPSP after…

A

1 - 5 msec.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Types of Summation

A

1) Time summation
2) Space summatiom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Time Summation

A

One presynaptic neuron is stimulated repetitively.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Space Summation

A

Several presynaptic neurons are stimulated simultaneously.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is IPSP?

A
  • A local state of partial hyperpolarization of the post synaptic membrane.
  • Produced as a result of binding of an inhibitory neurotansmitter with its receptors.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Ionic basis of IPSP

A
  • Opening of ligand-gated Cl- channels.
  • Closure of Na+ (or Ca++) channels.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

IPSP on neuron potential

A

It makes the inside of the cell membrane more negative, thereby less excitable as it is now away from the firing level.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Maximum of IPSP after…

A

1 - 2 msec.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is GPSP ?

A

It is the summation of all EPSPs & IPSPs occurring at the same time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Outcomes of GPSP

A
  • A balance of excitatory & inhibitory inputs, so the PSMP remains close to the RMP.
  • If Excitatory inputs slightly > Inhibitory inputs, Excitatory state (facilitation).
  • If Excitatory inputs much > Inhibitory inputs, threshold is reached an AP will be generated.
  • If Inhibitory inputs > Excitatory inputs, Inhibitory state (inhibition).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Postsynaptic Potentails

A
  • Do not obey all or none law.
  • Graded.
  • No absolute refractory period.
  • Summated.
  • Not blocked by anesthesia.
  • Not propagated.
  • 20 msec.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Action Potentials

A
  • Obey all or none law.
  • Can not be graded.
  • Absolute refractory period.
  • Can not be summated.
  • Blocked by anesthesia.
  • Propagated.
  • 1 msec.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Lowest threshold potentail is at…

A

Axon Hillox

20
Q

Presynaptic Inhibition

A
  • 3rd Inhibitory neuron.
  • Axo-axonic synapse.
  • Excitatory Presynaptic neuron.
  • Inhibitory Neurotransmitter e.g. GABA.
  • Ionic basis: Openning of Cl- or K+ channels.
  • Hyperpolarization ==> reduced Ca++ influx ==> reduced release of neurotransmitter ==> reduced transmission.
21
Q

Presynaptic Facilitation

A
  • 3rd Excitatory neuron.
  • Axo-axonic synapse.
  • Excitatory Presynaptic neuron.
  • Excitatory Neurotransmitter e.g. 5-HT.
  • Increases cAMPin presynaptic terminals ==> Closure of K+ channels
  • Prolongated Depolarization ==> more Ca++ influx ==> more release of neurotransmitter ==> more transmission.
22
Q

Characters of Synaptic transmission

A

1) Unidirectional
2) Synaptic delay
3) Fatigue
4) Synaptic plasticity

23
Q

Unidirectionality

A

One way only.
From Presynaptic to Postsynaptic neuron.

24
Q

Synaptic Delay

A

The time taken by an impulse to be conducted through the synapse.

25
Q

The Synaptic Delay represents …

A

1) The release of the chemical transmitter.
2) Its union with the receptors.
3) Opening of ionic channels.
4) Efflux of ions and building up of the postsynaptic potential to threshold value by summation.

26
Q

Usage of Synaptic Delay

A

Calculation of Number of synapses in any reflex arc.

27
Q

Fatigue

A

Decreased rate of impulses discharged from POSTsynaptic neuron after repetitive stimulation of PREsynaptic neuron.

28
Q

Causes of Fatigue state

A

1) Exhaustion of synaptic vesicles in the presynaptic terminals by repetitive stimulation.
2) Inactivation of postsynaptic receptors.

29
Q

Importance of Synaptic Fatigue

A

It stablizes the nervous system e.g. stopping discharge from overexcited areas in CNS during epileptic seizures.

30
Q

Synaptic Plasticity

A

The ability to change or remodulate the function according to the demand placed on the synapse. So the synaptic transmission can be strengthened or weakened for short or long duration based on past experience.
These changes can be Presynaptic or Postsynaptic.

31
Q

Importance of Synaptic Plasticity

A

They represent forms of learning and memory.

32
Q

Forms of Synaptic Plasticity

A

1) Post-tetanic Potentiation.
2) Habituation.
3) Sensitization.
4) Long-term Potentiation.
5) Long-term Depression.

33
Q

Post-tetanic Potentiation (PTP) Definition

A
  • Continuous discharge from POSTsynaptic neuron after application of BRIEF TETANIZING train of impulses to a PREsynaptic neuron.
  • It may last for few seconds to minutes.
34
Q

Ionic basis of PTP

A

Accumulation of Ca++ in the presynaptic neuron after repetitve stimulation ==> Continuous release of neuritransmitter & Enhanced EPSPs until Ca++ pump can remove it.

35
Q

Importance of PTP

A

Basic mechanism of IMMEDIATE memory.

36
Q

Habituation Definition

A

Gradual loss of response to REPEATED BENIGN or NEUTRAL stimuli.

37
Q

Ionic basis of Habituation

A

Gradual inactivation of Ca++ channels in the PREsynaptic terminals ==> decreased intracellular Ca++ ==> decreased release of neurotransmitter ==> transmission becomes weaker on repeated stimulation.

38
Q

Importance of Habituation

A

Adaptation to benign stimuli e.g. noises.

39
Q

Sensitization Definition

A

Augmented response of Postsynaptic neuron to mild stimuli after habituated stimulus is paired with a noxious stimulus.

40
Q

Ionic basis of Sensitization

A

Presynaptic Facilitation:
A noxious stimulus activates a 3rd excitatory neuron secreting Serotonin ==> cAMP ==> Closure of K + channels ==> prolonged postsynaptic depolarization ==> prolonged Ca++ influx ==> excess neurotransmitter release ==> enhanced synaptic transmission.

41
Q

Importance of Sensitization

A

1) The basis of SHORT-term memory.
2) Long-term memory ++ protein synthesis & growth of pre & post synaptic neurons and their connections.

42
Q

Long-Term Potentiation (LTP)

A
  • Persistent strengthening of the synaptic connections after repetitve stimulation.
  • Resembles PTP but much more prolonged and can last for days or weeks.
  • Various parts but specifically HIPPOCAMPUS.
43
Q

Ionic basis of LTP

A

Glutamate stimulates NMDA & AMPA receptors ==> Depolarization of the postsynaptic neuron ==> Relieves the Mg++ block in the NMDA receptors ==> Ca++ & Na+ influx ==> Insertion of additional AMPA receptors into the postsynaptic membrane ==> the postsynaptic neuron is more likely to fire in response to presynaptic stimulation.

44
Q

Long-Term Depression (LTD)

A
  • Persistent weakening of the synaptic connections after its stimulation.
  • The opposite of LTP but in the same fibers particularly in the hippocampus.
45
Q

Ionic basis of LTD

A

CA++ ions that enter the through NMDA receptors initiate a different signaling cascade ==> removal of the AMPA receptors ==> decreasing the synaptic response.

Physiology of Neuroscience 1 (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions