// Main VL Template
#import "../preamble.typ": *
 
#show: conf.with(
	// May add more flags here in the future
	num: 3
)

= Synapses

The synapses are the connection between two neurons.

The transportation of the signal goes in three stages $"chemical" -> "electrical" -> "chemical"$.

Chemical synapses are very common for learning.

There are different neurotransmitters.
Where as GABA is the most present inhibitory transmitter (it makes the AP more negative).
Glutamate is the most relevant exititory transmitter.
Glycine is also inhibitory. 
NMDA is a chemical agonist. It opens just certain channels.

The presynaptic signal does depolarize the other cell to be positive.

The reversal potiential does start when you open all the channels it is usually plus 30.

Q: What is LTP?

Synapses are used to trasmit signals from the axon of a source to the dendrite of a target neuron. 

There are electrical and chemical synases. 
At an electrical synapse we have direct electrial coupling 
At a chemical synapse a chemical subastanse is used to trasport the signal.

Electrical synapses operate bi -directional and are extremely fast.


AP creates a negative calcium current which are opeing the cages for the transmitters.

EPSP and IPSP

General reduction of the Hodgkin-Huxley Model

2 dimensioanl Neuron Models

$
	tau (dif u) / (dif t) = F (u,w) + I (t) \
	tau_(w) (dif w) / (dif t) =  G (u,w)
$
where $I (t)$ is a Stimulus.

This leads to the following equations where $beta and gamma$ are constants.
$ (dif u) / (dif t) =  u - (u^3 ) / (3) - w + I \
(dif w) / (dif t) =  epsilon (u +  beta - gamma w) \
$

An introductionary example is the harmonix Oscillator (already did this in physics class).

The crossing of the nullclines show the fixpoints.

Van der Pol differential equations.

