Topic 8.1 Flashcards
How is information encoded in the nervous system? (3)
- labelled lines
- spatial maps
- Pattern of nerve impulses
neural network function (3 steps)
1) input
2) computation
3) output
Most frequent nt for EPSP
glutamate
What are the 2 glutamate receptor types?
- ionotropic
- metabotropic
Most frequent nt for IPSP
GABA
GABA receptor types
GABA a : ligand gated Cl- channel
Gaba b : Gi coupled
How is anion selectivity determined for GABA a?
Charged AA side chains inside the channel
Analog receptors to GABAa (3)
- Glycine R (anion channel)
2. nACHR, 5HT3R (cation channels)
How is amplitude of combined PSP encoded?
In the AP frequency
How is rythmic bursting activity explained?
Presence of VDCC + Calcium dependant K+ channel
Types of channels in non adapting neuron?
- quick voltage gated Na+ channel
- K+ channel
Type of channel in adapting neuron
slowly activating, voltage gated K+ channel
Example of retrograde signaling
With 2-arachydonylglycerol and CB1R
Which glutamate receptors are GQ coupled?
metabotropic type 1 and 5
WHich enzyme converts DAG - 2AG
DAG lipase
What type of substance is 2-AG
endocanabinoid
What is synaptic plasticity?
If AP frequency / pattern changes, strength of connection between 2 neurons may change
What is synaptic strength?
the mean amplitude of the post synaptic response (EPSP)
4 types of synaptic strength increase
- facilitation
- Augmentation
- Potentiation
- Long term potentiation (LSP)
What can synaptic strength decrease be a result of? (3)
- habituation
- depression
- long term depression
Where is long term potentiation observed?
in the hippocampus
Volume of brain occupied by glial cells
1/2 volume of the brain
CNS glial cell types (3)
- Astrocytes
- Oligodendrocytes
- Microglial cells
Types of astrocytes (6)
- Fibrous
- Protoplasmic
- Radial glial cell
- Müller cell
- Bergmann glia
- Ependymal cell
Where are satellite cells found?
in sensory and autonomic ganglia
Glial cells in the PNS (3)
- Satellite cells
- Enteric glial cells
- Schwann cells
How can astrocytes be identified
By their specific intermediate filament GFAP
Functions of astrocytes (5)
- Provide fuel in the form of lactate
- Regulate K+ and pH of brain and ECF
- Glutamate / glutamine cycle
- Secrete trophic factors BDNF and GDNF
- Modulate cerebral blood flow (neural activity induced vasodilation)
2 ways for glucose to reach neuron
Direct path (glut 3) Transastrocyte path (glut1)
What is MCT 1 & 2
Monocarboxylate transporter : lactate and H+ co transporter
Brain ECF [K+] + during max activity
3mM or 2.8mM
Max activité : 12mM
Glutamate concentration in neuron
10mM
Glutamate concentration EC
1 microM
Where do microglial cells derive from?
Monocyte macrophage lineage
What do microglial cells release when activated?
They release cytokines, free radicals and NO
