Synaptic and Jucntional Transmission Flashcards
What is the basic functional unit of the brain
Neuron
this is where the incoming signals enter and this also determines where the signal will go
Synapse
where is synapse located?
Dendrites and Cell bodies
output signal travels through this
Axon
This is the Junction point from one neuron to another
Synapse
this area is where two neurons come close together enough to exchange information
Synapse
This is the space where neurotransmitters are released from presynaptic and binds to post synaptic
Synaptic Cleft
information transmitted in the CNS in the form of nerve action potentials
Nerve impulse
Transmission of Information via Two Types
- Presynaptic
- Post synaptic
this transmission sends info and where info is initiated
Presynaptic
this transmission receives info
Postsynaptic Neuron
2 types of synapses
- -Electrical
- Chemical Synapse
this synapse secretes chemical substance neurotransmitter
Chemical Synapse
this synapse is directly connect to the cluster of ion channes called gap junctions
Electrical Synapses
this synapse give bidirectional transmission of the synapse
-in reflex pathways
Electrical Synapse
Cluster of Ions that has a plaque like structure
- allows free movement
- has connexin (6)
Gap junctions
the hexagonal unit in the gap junctions is called
Connexon
this is the most used type of synapse
- neurotransmitter
- excites or inhibits
- one way conduction
- presy to postsy
Chemical Synapse
this synapse has a principle of one way conduction
pre to postsy
Chemical Synapse
This terminal vesicle contains the neurotransmitter when released by the synaptic cleft
Presynaptic Cleft
This terminal responses based on the receptor present in the
Post synaptic terminal
What is the most studied neurotransmitter in the presynaptic terminal
Acetylcholine
What are the components of receptor proteins
- Binding Component
- Intracellular component
this is where the neurotransmitter from the presynaptic binds
Binding component
this component passes all the way through the postsynaptic into the post synaptic neuron
Intracellular Component
Types of Receptor proteins
-Ionotropic
-Metabotropic
-
this type of receptor protein is: - ligate ion channeled - allows passage of ions - Fast synpase -
Ionotropic
Two types of Ionotropic receptor
- Cation
- Anion
this type of ionotrpic allows passage of CL
- opened by inhibitory neurotransmitter
- Anion channel
this type of ionotropic allows passage of K, NA, Calcium
- opened by excitatory neurotransmitter
Cation Channels
This type of protein receptor:
- activates 2ndary g-proteins
- secondary relays message which causes increase or decrease of cell activity
- prolonged effect
Metabotropic
2 states of Metabotropic
- Inactive state
- Activation state
this metabotropic state :
- free in the cytosol
- has alpha, beta, gamma are bound together
- gdp is attached to alpha
Inactivated state
this metabotropic type:
- attaches from presyp
- changes form
- g protein binds
- simultaneous release of gdp
- beta and gamma disassociate
- alpha is free to move
Activation metabotropic state
What are the Functions of Activation state of Metabotropic
- opens specific ion channels through post synaptic
- activates camp
- activates gene
- hydrolysis
- beta and y attaches to @
- stable G-p
This is the gap between motor neuron and skeletal muscle fiber
Neuromuscular Junction
Mechanism of Neuromuscular junction
- Voltage Ca2+ opens
- ca2+ flows
- influx of CA+ and ACh
- ACH binds
- influx of NA+
- End plate
How does Ach form
- Choline transfers
What enzyme forms ACh
Choline Acetyltransferase
(Acetyl-CoA) + (Choline) . (ACh) + (CoA)
Choline is recycled from ACh by Acetylcholinesterase
(AChE).
(ACh) . (Acetyl-CoA) + (Choline)
This brings the membrane potential of postsynap closer to threshold providing excitatory effects
Postsynaptic Potentials
This is a result of Ion fast channels or slow channels.
- brings membrane potential closer to threshold
- increase RMP to high enough positive
Excitatory Postsynaptic Potentials (EPSP)
type of EPSP facilitated by ionotropic receptors
- efflux of K and influx of NA
- NA entering potential is higher
Fast Excitatory Postsynaptic Potential
PEPSP
type of epsp created from metabotropic
- this activates the gprotein
- produces Camp
- protein kinase
- inhibits K from intracellular
Slow excitatory Post synnaptic potential
SEPSP
types of Inhibitory Post synaptic potential (IPSP)
- Fast IPSP
The goal of this is to bring the PostP to threshold by hyperpolarizing or by stabilizing resting membrane potential
IPSP
How is IPSP accomplised
-Opening potassium channels that increases conductance
of potassium ions out of the neuron
- Opening potassium channels that increases conductance
of potassium ions out of the neuron
another mechanism of IPSP
inhibition is the activation of
receptor enzymes that inhibit cellular metabolic functions
that increase the number of inhibitory synaptic receptors or
the occurence of IPSP is very fast so it only uses Ionotropic receptors
True
Two channels in the IPSP
- K
- CL
Increases internal negativity
Hyper polarization
This channel
- opens K channels will allow ++ to go out to make inner –
Potassium channels
this channel opens chloride pump
- chloride channels open so negative chloride ions enter into interrior membrane to make it more negative (-70mv)
Chloride channel
this moves out of the cell to make it negative when opened
Potassium
this moves inside the cell to make it negative when opened
Chloride
neuromuscular junction represents a simple type of
synapse type of synapse
neuromuscular junction represents a simple type of
synapse type of synapse
this type of neuromuscular synapse: - input and out are same - AP from presyp will induce AP in postp - 1 is to 1 AP in post -
One is to one synapse
this type of neuromuscular synapse:
- action potential in a presynaptic cell= several
action potential in a postsynaptic cell.
One is to Many synapse
this type of neuromuscular synapse:
- one action potential in the presynaptic cell
is not enough to make postsynaptic terminal fire an action
potential
- many AP arrives
- used by the brain
MANY TO ONE SYNAPSE
how many synapse are need to form intermediate memory
In order to form memory traces that could be converted
into an intermediate memory, two presynaptic neurons.
