  In this paper, we are aiming to propose a novel mathematical model that
studies the dynamics of synaptic damage in terms of concentrations of toxic
neuropeptides/neurotransmitters during neurotransmission processes. Our primary
objective is to employ Wardrop's first and second principles within a neural
network of the brain. In order to comprehensively incorporate Wardrop's first
and second principles into the neural network of the brain, we introduce two
novel concepts: \textit{neuropeptide's (neurotransmitter's) equilibrium} and
\textit{synapses optimum}. The \textit{neuropeptide/neurotransmitter
equilibrium} refers to \textit{a distribution of toxic
neuropeptides/neurotransmitters that leads to uniform damage across all
synaptic links}. Meanwhile, \textit{synapses optimum} is \textit{the most
desirable distribution of toxic neuropeptides/neurotransmitters that minimizes
the cumulative damage experienced by all synapses}. In the context of a neural
network within the brain, an analogue of the price of anarchy is \textit{the
price of cognition} which is \textit{the most unfavorable ratio between the
overall impairment caused by toxic neuropeptide's (neurotransmitter's)
equilibrium in comparison to the optimal state of synapses (synapses optimum)}.
To put it differently, \textit{the price of cognition} measures \textit{the
loss of cognitive ability resulting from increased concentrations of toxic
neuropeptides/neurotransmitters}. Additionally, a replicator equation is
proposed within this framework that leads to the establishment of the synapses
optimum during the neurotransmission process.
