3 ms·

Are neuromodulators released locally to a cortical column, i.e. with controlled spatial concentration? I guess they must be, to have specific effects, but they

• periheli0n 6y ago
  Locally, neuromodulators disperse through diffusion, unlike neurotransmitters which are hardly given a chance to travel far from the synaptic cleft they are released into, due to reuptake channels and enzymatic degradation. But neurons that release neuromodulators innervate large portions of the brain; that is, when one such a neuron is active it releases neuromodulators all across the brain. The mechanism how Neuromodulators can have specific effects in spite of their global delivery is one of the many open questions about brain function. Part of the solution is that different neuron types respond differently to the same neuromodulator. Depending on the abundance of certain neuron types in a circuit, different circuits can also respond differently to the same neuromodulator.