The code provided is part of a computational model designed to simulate synaptic inputs on the dendrites of neurons. This model specifically focuses on excitatory synapses mediated by AMPA and NMDA receptors, which play crucial roles in synaptic transmission and plasticity in the mammalian brain. Below, we explore the biological foundation of this model:
Dendritic Spines and Shafts: The model incorporates two types of synaptic inputs based on their location:
The code distinguishes between these based on the shaftInput
variable and determines synaptic placement accordingly.
AMPA Receptors (AMPARs):
Exp2Syn
for simulating AMPAR-mediated synapses.NMDA Receptors (NMDARs):
Exp2SynNMDA
for simulating NMDAR-mediated synapses.These receptors' time constants (tau1
and tau2
) are set based on empirical research (e.g., Harnett et al., 2012).
The dynamic alteration of synaptic weights (weightAmpa
and weightNmda
) and the ability to modify synaptic start times (nsAmpa
and nsNmda
) mirror the plastic nature of synapses, highlighting synaptic strength changes and timing crucial for learning processes like Hebbian plasticity.
The section involving synapse placement and movement reflects the biological concept of synaptic clustering versus distributed inputs:
The function getParentX()
to access parent compartment values emphasizes the model's consideration of dendritic morphology, impacting how inputs integrate across the dendritic tree.
In summary, the code models critical aspects of synaptic transmission and plasticity, reflecting biological processes in neuronal dendrites. This encompasses the interaction between AMPA and NMDA receptor-mediated inputs, their contribution to synaptic plasticity, and the spatial organization of synapses on dendrites, vital for information processing and cognitive functions in the brain.