Axon terminals always form synapses rather than releasing neurotransmitters into the extracellular space
the verdict
REFUTED
the evidence says no
confidence 12/100
Axon terminals do not exclusively form classical synapses; many release neurotransmitters directly into the extracellular space to engage in volume or extrasynaptic transmission.
Evidence against · 5
Dopaminergic transmission in the rat retina: evidence for volume transmission.
1996 · cited by 78
Demonstrates that dopaminergic transmission in the retina operates via volume transmission by releasing neurotransmitters into the extracellular space where they diffuse to distant receptors.
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More against · 4
Dopaminergic neurons establish a distinctive axonal arbor with a majority of non-synaptic terminals
2020 · cited by 31
Shows that monoamine neurons, such as dopaminergic neurons, establish a majority of non-synaptic terminals that release neurotransmitters without forming classical synapses.
Wiring and Volume Transmission: An Overview of the Dual Modality for Serotonin Neurotransmission.
2023 · cited by 28
Discusses volume transmission as a dual modality where neuroactive molecules undergo extrasynaptic diffusion rather than point-to-point wiring transmission.
Molecular Anatomy of Synaptic and Extrasynaptic Neurotransmission Between Nociceptive Primary Afferents and Spinal Dorsal Horn Neurons
2025 · cited by 13
Reports that certain molecules like neuropeptides are released extrasynaptically to modulate neuronal function via volume transmission rather than forming direct synaptic contacts.
Nonsynaptic Diffusion Neurotransmission and Brain Plasticity
1996 · cited by 3
Explains nonsynaptic diffusion neurotransmission, where neurotransmitters diffuse through the extracellular fluid from remote release points to activate extrasynaptic receptors.