Synaptic Dynamics#

Synaptic dynamics refers to the processes that modulate the strength of synaptic connections between neurons in the brain. Key aspects of synaptic dynamics include:

  • Synaptic plasticity - the ability of synaptic strength to change in response to neuronal activity. This includes phenomena like long-term potentiation (LTP) and long-term depression (LTD) which increase or decrease synaptic strength based on patterns of activity. These processes allow synapses to strengthen or weaken over time and are important for learning and memory.

  • Short-term synaptic plasticity - rapid, short-lived changes in synaptic strength in response to recent activity patterns. This includes short-term facilitation and depression. These transient changes allow synapses to exhibit short-term memory and alter their function on the timescale of milliseconds to minutes.

  • Homeostatic plasticity - slower compensatory mechanisms that maintain optimal overall activity levels in neurons and networks by globally scaling up or down synaptic strengths. This stabilizes network function.

  • Neuromodulation - the ability of neuromodulators like dopamine, acetylcholine and serotonin to alter synaptic transmission, often by changing synaptic plasticity. This allows global shifts in network dynamics and learning rules.

  • Synaptic noise - fluctuations in synaptic transmission due to the stochastic nature of neurotransmitter release. This variability impacts signal transmission and synaptic plasticity.

  • Synaptic integration and dynamics - how incoming signals at many thousands of synapses are integrated and processed in individual neurons, altering their computational functions. This depends on synaptic dynamics.

So in summary, synaptic dynamics describe the various processes that change the properties of synapses in the brain over timescales ranging from milliseconds to hours/days. These dynamics ultimately regulate how information is transmitted and encoded in neural circuits.

Phenomenological synapse models#

Delta

Delta synapse model.

Expon

Exponential decay synapse model.

Alpha

Alpha synapse model.

DualExpon

Dual exponential synapse model.

DualExponV2

Dual exponential synapse model.

NMDA

NMDA synapse model.

STD

Synaptic output with short-term depression.

STP

Synaptic output with short-term plasticity.

Biological synapse models#

AMPA

AMPA synapse model.

GABAa

GABAa synapse model.

BioNMDA

Biological NMDA synapse model.

Gap junction models#

DiffusiveCoupling

Diffusive coupling.

AdditiveCoupling

Additive coupling.