Spiking Neural Networks (SNNs) model biological neural dynamics more faithfully than classical artificial networks, but their stochastic, event-driven computation -- rooted in ion-channel noise and unreliable synaptic vesicle release -- demands probabilistic models for which deterministic abstractions are mathematically inadequate. Formal verification of such models via probabilistic model checking faces a fundamental barrier: the state space explosion problem, where the Discrete-Time Markov Chain (DTMC) encoding grows exponentially with the number of neurons. General-purpose quotient model abstractions [1] can in principle mitigate this growth by partitioning membrane potentials into equivalence classes, but a naïve application to SNNs discards synaptic weight information, limiting the properties that can be verified. This paper introduces a weight-discretized quotient model abstraction that maps continuous synaptic weights to a compact integer range while preserving the relative contribution of each synapse, and presents CogSpike, a unified workbench that integrates SNN design, simulation, and PRISM-based formal verification within a single isomorphic tool chain. The discretization is accompanied by formal correctness guarantees: a two-sided fidelity theorem confines any firing disagreement to a bounded gray zone around threshold, and an Asymptotic Silence theorem gives the exact limit guarantee that unforced neurons fall permanently silent. A topology-dependent scaling analysis shows that the state space reduction compounds exponentially -- approximately $17\times$ per neuron for discretization parameter $W = 3$ -- enabling verification of networks that are otherwise intractable, as confirmed empirically across seven canonical topologies.
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