Neuromodulation and Plasticity Flashcards Preview

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Flashcards in Neuromodulation and Plasticity Deck (16):
1

neuromodulation

refers to mechanisms that change how info is being processed through nervous system. Modulate neurons and neural circuits. Good drug target

2

Two dominant mechanisms for neuromodulation

1. changing intracellular Ca2+ to trigger activation of specific Ca2+ regulatory enzyme systems
2. Activation of specific G-proteins that couple to the activation or inhibition of different enzyme cascades

3

What are the two primary ways that intracellular Ca is raised?

- NMDA receptor
- voltage gated Ca channel

4

What are the primary neuromodulatory systems?

- cholinergic (CNS Ach = neuromodulatory)
- catacholamines - (i.e. dopamine)
- indoleamines - (i.e. serotonin)
- neuropeptides - change state or regulate pain

5

What is the primary indoleamine?

serotonin

6

How are peptide transmitters synthesized?

into VESICLES in ER as inactive precoursers. Proteolytic cleavage within vesicle produces active peptides

7

Learning/memory vs. plasticity

learning = ORGANISM LEVEL changes, change in behavior, experience

plasticity = cellular/circuit change within nervous system, changes in firing in response to the same stimulus

8

What is the key factor involved in learning/memory and plasticity?

EXPERIENCE!

changes can be related to a pattern of preceding experiences that trigger interonal neronal mechanisms that modulate nervous system function

9

Two main classes of plasticity?

excitability - changes in likelihood of firing APs in response to same stimuli

synaptic - changes in the strengths of connections between neurons

10

plasticity temporal domains (time classifications)

short term - (msec to sec). Involves changes in gates/cellular Ca

intermediate - (seconds to hours) - involves covalent bonds, phosphorylation, proteolysis, red-ox sensitivity

long term - (hours to days) - transcription, translation, alt splicing....needs an opposing long term plasticity mechanism to revert...HARD TO REVERSE

11

How are neuronal connectivity patterns regulated?

genetically regulated

12

How are synaptic strengths and neuronal excitability modulated?

EXPERIENCE

13

coincidence detection

involves response to multiple factors at the same time. specific molecular mechanisms exist that can create an association between multiple factors and produce a conditional change in enuronal function

14

What is the classic example of coincidence detection?

NMDA receptor

15

What is involved in NMDA receptor in coincidence detection?

Mg2+ blocking...this means that when Mg blocking is active, NMDA receptors can only pass current when cell is depolarized.

EXTRACELLULAR MG2+ IONS BLOCK NMDA CURRENTS AT NEGATIVE POTENTIALS

16

What is still flowing inward, despite a Mg block?

Ca!!!!

During an Mg block, Ca ions are flowing into the cell when a spike in glutamate happens while all other outward things are